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Li X, Cheng X, Xu J, Wu J, Chan LL, Cai Z, Zhou J. Dynamic patterns of carbohydrate metabolism genes in bacterioplankton during marine algal blooms. Microbiol Res 2024; 286:127785. [PMID: 38851011 DOI: 10.1016/j.micres.2024.127785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Revised: 05/01/2024] [Accepted: 05/25/2024] [Indexed: 06/10/2024]
Abstract
Carbohydrates play a pivotal role in nutrient recycling and regulation of algal-bacterial interactions. Despite their ecological significance, the intricate molecular mechanisms governing regulation of phycosphere carbohydrates by bacterial taxa linked with natural algal bloom have yet to be fully elucidated. Here, a comprehensive temporal metagenomic analysis was conducted to explore the carbohydrate-active enzyme (CAZyme) genes in two discrete algal bloom microorganisms (Gymnodinium catenatum and Phaeocystis globosa) across three distinct bloom stages: pre-bloom, peak bloom, and post-bloom. Elevated levels of extracellular carbohydrates, primarily rhamnose, galactose, glucose, and arabinose, were observed during the initial and post-peak stages. The prominent CAZyme families identified-glycoside hydrolases (GH) and carbohydrate-binding modules (CBMs)-were present in both algal bloom occurrences. In the G. catenatum bloom, GH23/24 and CBM13/14 were prevalent during the pre-bloom and peak bloom stages, whereas GH2/3/30 and CBM12/24 exhibited increased prevalence during the post-bloom phase. In contrast, the P. globosa bloom had a dominance of GH13/23 and CBM19 in the initial phase, and this was succeeded by GH3/19/24/30 and CBM54 in the later stages. This gene pool variation-observed distinctly in specific genera-highlighted the dynamic structural shifts in functional resources driven by temporal alterations in available substrates. Additionally, ecological linkage analysis underscored a correlation between carbohydrates (or their related genes) and phycospheric bacteria, hinting at a pattern of bottom-up control. These findings contribute to understanding of the dynamic nature of CAZymes, emphasizing the substantial influence of substrate availability on the metabolic capabilities of algal symbiotic bacteria, especially in terms of carbohydrates.
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Affiliation(s)
- Xinyang Li
- Marine Ecology and Human Factors Assessment Technical Innovation Center of Natural Resources Ministry, Tsinghua Shenzhen International Graduate School, Shenzhen, Guangdong Province 518055, PR China; Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong Province 518055, PR China; Shenzhen Key Laboratory of Advanced Technology for Marine Ecology, Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong Province 518055, PR China
| | - Xueyu Cheng
- Marine Ecology and Human Factors Assessment Technical Innovation Center of Natural Resources Ministry, Tsinghua Shenzhen International Graduate School, Shenzhen, Guangdong Province 518055, PR China; Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong Province 518055, PR China; Shenzhen Key Laboratory of Advanced Technology for Marine Ecology, Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong Province 518055, PR China
| | - Junjie Xu
- Marine Ecology and Human Factors Assessment Technical Innovation Center of Natural Resources Ministry, Tsinghua Shenzhen International Graduate School, Shenzhen, Guangdong Province 518055, PR China; Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong Province 518055, PR China; Shenzhen Key Laboratory of Advanced Technology for Marine Ecology, Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong Province 518055, PR China
| | - Jiajun Wu
- State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong, China
| | - Leo Lai Chan
- State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong, China
| | - Zhonghua Cai
- Marine Ecology and Human Factors Assessment Technical Innovation Center of Natural Resources Ministry, Tsinghua Shenzhen International Graduate School, Shenzhen, Guangdong Province 518055, PR China; Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong Province 518055, PR China; Shenzhen Key Laboratory of Advanced Technology for Marine Ecology, Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong Province 518055, PR China
| | - Jin Zhou
- Marine Ecology and Human Factors Assessment Technical Innovation Center of Natural Resources Ministry, Tsinghua Shenzhen International Graduate School, Shenzhen, Guangdong Province 518055, PR China; Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong Province 518055, PR China; Shenzhen Key Laboratory of Advanced Technology for Marine Ecology, Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong Province 518055, PR China.
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Hamilton M, Ferrer‐González FX, Moran MA. Heterotrophic bacteria trigger transcriptome remodelling in the photosynthetic picoeukaryote Micromonas commoda. ENVIRONMENTAL MICROBIOLOGY REPORTS 2024; 16:e13285. [PMID: 38778545 PMCID: PMC11112143 DOI: 10.1111/1758-2229.13285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 04/30/2024] [Indexed: 05/25/2024]
Abstract
Marine biogeochemical cycles are built on interactions between surface ocean microbes, particularly those connecting phytoplankton primary producers to heterotrophic bacteria. Details of these associations are not well understood, especially in the case of direct influences of bacteria on phytoplankton physiology. Here we catalogue how the presence of three marine bacteria (Ruegeria pomeroyi DSS-3, Stenotrophomonas sp. SKA14 and Polaribacter dokdonensis MED152) individually and uniquely impact gene expression of the picoeukaryotic alga Micromonas commoda RCC 299. We find a dramatic transcriptomic remodelling by M. commoda after 8 h in co-culture, followed by an increase in cell numbers by 56 h compared with the axenic cultures. Some aspects of the algal transcriptomic response are conserved across all three bacterial co-cultures, including an unexpected reduction in relative expression of photosynthesis and carbon fixation pathways. Expression differences restricted to a single bacterium are also observed, with the Flavobacteriia P. dokdonensis uniquely eliciting changes in relative expression of algal genes involved in biotin biosynthesis and the acquisition and assimilation of nitrogen. This study reveals that M. commoda has rapid and extensive responses to heterotrophic bacteria in ways that are generalizable, as well as in a taxon specific manner, with implications for the diversity of phytoplankton-bacteria interactions ongoing in the surface ocean.
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Affiliation(s)
- Maria Hamilton
- Department of Marine SciencesUniversity of GeorgiaAthensGeorgiaUSA
| | | | - Mary Ann Moran
- Department of Marine SciencesUniversity of GeorgiaAthensGeorgiaUSA
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3
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Han D, Park KT, Kim H, Kim TH, Jeong MK, Nam SI. Interaction between phytoplankton and heterotrophic bacteria in Arctic fjords during the glacial melting season as revealed by eDNA metabarcoding. FEMS Microbiol Ecol 2024; 100:fiae059. [PMID: 38621717 PMCID: PMC11067963 DOI: 10.1093/femsec/fiae059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 04/07/2024] [Accepted: 04/13/2024] [Indexed: 04/17/2024] Open
Abstract
The hydrographic variability in the fjords of Svalbard significantly influences water mass properties, causing distinct patterns of microbial diversity and community composition between surface and subsurface layers. However, surveys on the phytoplankton-associated bacterial communities, pivotal to ecosystem functioning in Arctic fjords, are limited. This study investigated the interactions between phytoplankton and heterotrophic bacterial communities in Svalbard fjord waters through comprehensive eDNA metabarcoding with 16S and 18S rRNA genes. The 16S rRNA sequencing results revealed a homogenous community composition including a few dominant heterotrophic bacteria across fjord waters, whereas 18S rRNA results suggested a spatially diverse eukaryotic plankton distribution. The relative abundances of heterotrophic bacteria showed a depth-wise distribution. By contrast, the dominant phytoplankton populations exhibited variable distributions in surface waters. In the network model, the linkage of phytoplankton (Prasinophytae and Dinophyceae) to heterotrophic bacteria, particularly Actinobacteria, suggested the direct or indirect influence of bacterial contributions on the fate of phytoplankton-derived organic matter. Our prediction of the metabolic pathways for bacterial activity related to phytoplankton-derived organic matter suggested competitive advantages and symbiotic relationships between phytoplankton and heterotrophic bacteria. Our findings provide valuable insights into the response of phytoplankton-bacterial interactions to environmental changes in Arctic fjords.
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Affiliation(s)
- Dukki Han
- Department of Marine Molecular Bioscience, Gangneung-Wonju National University, Gangneung 25457, Republic of Korea
| | - Ki-Tae Park
- Korea Polar Research Institute, Incheon 21990, Republic of Korea
- Department of Environmental Sciences and Biotechnology, Hallym University, Chuncheon 24252, Republic of Korea
| | - Haryun Kim
- East Sea Research Institute, Korea Institute of Ocean Science & Technology, Uljin 36315, Republic of Korea
| | - Tae-Hoon Kim
- Department of Oceanography, Faculty of Earth Systems and Environmental Sciences, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Man-Ki Jeong
- Department of Smart Fisheries Resources Management, Chonnam National University, Yeosu 59626, Republic of Korea
| | - Seung-Il Nam
- Korea Polar Research Institute, Incheon 21990, Republic of Korea
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4
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Wang Y, Jiao M, Zhao Z, Wang Y, Li T, Wei Y, Li R, Yang F. Insight into the role of niche concept in deciphering the ecological drivers of MPs-associated bacterial communities in mangrove forest. WATER RESEARCH 2024; 249:120995. [PMID: 38071907 DOI: 10.1016/j.watres.2023.120995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 10/22/2023] [Accepted: 12/07/2023] [Indexed: 01/03/2024]
Abstract
Myriad inherent and variable environmental features are controlling the assembly and succession of bacterial communities colonizing on mangrove microplastics (MPs). However, the mechanisms governing mangrove MPs-associated bacterial responses to environmental changes still remain unknown. Here, we assessed the dissimilarities of MPs-associated bacterial composition, diversity and functionality as well as quantified the niche variations of each taxon on plastispheres along river-mangrove-ocean and mangrove landward-to-seaward gradients in the Beibu Gulf, China, respectively. The bacterial richness and diversity as well as the niche breadth on mangrove sedimentary MPs dramatically decreased from landward to seaward regions. Characterizing the niche variations linked the difference of ecological drivers of MPs-associated bacterial populations and functions between river-mangrove-ocean (microplastic properties) and mangrove landward-to-seaward plastispheres (sediment physicochemical properties) to the trade-offs between selective stress exerted by inherent plastic substrates and microbial competitive stress imposed by environmental conditions. Notably, Rhodococcus erythropolis was predicted to be the generalist species and closely associated to biogeochemical cycles of mangrove plastispheres. Our work provides a reliable pathway for tackling the hidden mechanisms of environmental factors driving MPs-associated microbe from perspectives of niches and highlights the spatial dynamic variations of mangrove MPs-associated bacteria.
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Affiliation(s)
- Yijin Wang
- College of Light Industry and Food Engineering, Guangxi University, Nanning 530004, China; School of Marine Sciences, Guangxi University, Nanning 530004, China
| | - Meng Jiao
- School of Marine Sciences, Guangxi University, Nanning 530004, China
| | - Zhen Zhao
- College of Light Industry and Food Engineering, Guangxi University, Nanning 530004, China
| | - Yinghui Wang
- Institute of Green and Low Carbon Technology, Guangxi Institute of Industrial Technology 16 Songxiang Road, Nanning 530004, China
| | - Tiezhu Li
- School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China
| | - Yihua Wei
- School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China
| | - Ruilong Li
- College of Light Industry and Food Engineering, Guangxi University, Nanning 530004, China.
| | - Fei Yang
- State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research of Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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5
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Shibl AA, Ochsenkühn MA, Mohamed AR, Isaac A, Coe LSY, Yun Y, Skrzypek G, Raina JB, Seymour JR, Afzal AJ, Amin SA. Molecular mechanisms of microbiome modulation by the eukaryotic secondary metabolite azelaic acid. eLife 2024; 12:RP88525. [PMID: 38189382 PMCID: PMC10945470 DOI: 10.7554/elife.88525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2024] Open
Abstract
Photosynthetic eukaryotes, such as microalgae and plants, foster fundamentally important relationships with their microbiome based on the reciprocal exchange of chemical currencies. Among these, the dicarboxylate metabolite azelaic acid (Aze) appears to play an important, but heterogeneous, role in modulating these microbiomes, as it is used as a carbon source for some heterotrophs but is toxic to others. However, the ability of Aze to promote or inhibit growth, as well as its uptake and assimilation mechanisms into bacterial cells are mostly unknown. Here, we use transcriptomics, transcriptional factor coexpression networks, uptake experiments, and metabolomics to unravel the uptake, catabolism, and toxicity of Aze on two microalgal-associated bacteria, Phycobacter and Alteromonas, whose growth is promoted or inhibited by Aze, respectively. We identify the first putative Aze transporter in bacteria, a 'C4-TRAP transporter', and show that Aze is assimilated through fatty acid degradation, with further catabolism occurring through the glyoxylate and butanoate metabolism pathways when used as a carbon source. Phycobacter took up Aze at an initial uptake rate of 3.8×10-9 nmol/cell/hr and utilized it as a carbon source in concentrations ranging from 10 μM to 1 mM, suggesting a broad range of acclimation to Aze availability. For growth-impeded bacteria, we infer that Aze inhibits the ribosome and/or protein synthesis and that a suite of efflux pumps is utilized to shuttle Aze outside the cytoplasm. We demonstrate that seawater amended with Aze becomes enriched in bacterial families that can catabolize Aze, which appears to be a different mechanism from that in soil, where modulation by the host plant is required. This study enhances our understanding of carbon cycling in the oceans and how microscale chemical interactions can structure marine microbial populations. In addition, our findings unravel the role of a key chemical currency in the modulation of eukaryote-microbiome interactions across diverse ecosystems.
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Affiliation(s)
- Ahmed A Shibl
- Biology Program, New York University Abu DhabiAbu DhabiUnited Arab Emirates
| | | | - Amin R Mohamed
- Biology Program, New York University Abu DhabiAbu DhabiUnited Arab Emirates
| | - Ashley Isaac
- Biology Program, New York University Abu DhabiAbu DhabiUnited Arab Emirates
- Max Planck Institute for Marine MicrobiologyBremenGermany
| | - Lisa SY Coe
- Biology Program, New York University Abu DhabiAbu DhabiUnited Arab Emirates
| | - Yejie Yun
- Biology Program, New York University Abu DhabiAbu DhabiUnited Arab Emirates
| | - Grzegorz Skrzypek
- West Australian Biogeochemistry Centre, School of Biological Sciences, The University of Western AustraliaPerthAustralia
| | - Jean-Baptiste Raina
- Climate Change Cluster, Faculty of Science, University of Technology SydneyUltimoAustralia
| | - Justin R Seymour
- Climate Change Cluster, Faculty of Science, University of Technology SydneyUltimoAustralia
| | - Ahmed J Afzal
- Biology Program, New York University Abu DhabiAbu DhabiUnited Arab Emirates
| | - Shady A Amin
- Biology Program, New York University Abu DhabiAbu DhabiUnited Arab Emirates
- Center for Genomics and Systems Biology (CGSB), New York University Abu DhabiAbu DhabiUnited Arab Emirates
- Arabian Center for Climate and Environmental Sciences (ACCESS), New York University Abu DhabiAbu DhabiUnited Arab Emirates
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6
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Chiou YJ, Chan YF, Yu SP, Lu CY, Hsiao SSY, Chiang PW, Hsu TC, Liu PY, Wada N, Lee Y, Jane WN, Lee DC, Huang YW, Tang SL. Similar but different: Characterization of dddD gene-mediated DMSP metabolism among coral-associated Endozoicomonas. SCIENCE ADVANCES 2023; 9:eadk1910. [PMID: 37992165 PMCID: PMC10664990 DOI: 10.1126/sciadv.adk1910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 10/20/2023] [Indexed: 11/24/2023]
Abstract
Endozoicomonas are often predominant bacteria and prominently important in coral health. Their role in dimethylsulfoniopropionate (DMSP) degradation has been a subject of discussion for over a decade. A previous study found that Endozoicomonas degraded DMSP through the dddD pathway. This process releases dimethyl sulfide, which is vital for corals coping with thermal stress. However, little is known about the related gene regulation and metabolic abilities of DMSP metabolism in Endozoicomonadaceae. In this study, we isolated a novel Endozoicomonas DMSP degrader and observed a distinct DMSP metabolic trend in two phylogenetically close dddD-harboring Endozoicomonas species, confirmed genetically by comparative transcriptomic profiling and visualization of the change of DMSP stable isotopes in bacterial cells using nanoscale secondary ion spectrometry. Furthermore, we found that DMSP cleavage enzymes are ubiquitous in coral Endozoicomonas with a preference for having DddD lyase. We speculate that harboring DMSP degrading genes enables Endozoicomonas to successfully colonize various coral species across the globe.
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Affiliation(s)
- Yu-Jing Chiou
- Institute of Oceanography, National Taiwan University, Taipei 106, Taiwan
- Biodiversity Research Center, Academia Sinica, Taipei 115, Taiwan
| | - Ya-Fan Chan
- Department of Microbiology, Soochow University, Taipei 111, Taiwan
| | - Sheng-Ping Yu
- Biodiversity Research Center, Academia Sinica, Taipei 115, Taiwan
| | - Chih-Ying Lu
- Biodiversity Research Center, Academia Sinica, Taipei 115, Taiwan
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, National Chung Hsing University and Academia Sinica, Taipei 115, Taiwan
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung 402, Taiwan
| | | | - Pei-Wen Chiang
- Biodiversity Research Center, Academia Sinica, Taipei 115, Taiwan
| | - Ting-Chang Hsu
- Biodiversity Research Center, Academia Sinica, Taipei 115, Taiwan
| | - Po-Yu Liu
- School of Medicine, College of Medicine, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
| | - Naohisa Wada
- Biodiversity Research Center, Academia Sinica, Taipei 115, Taiwan
| | - Yu Lee
- Department of Chemistry, National Tsing Hua University, Hsinchu 300, Taiwan
| | - Wann-Neng Jane
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 115, Taiwan
| | - Der-Chuen Lee
- Institute of Astronomy and Astrophysics, Academia Sinica, Taipei 115, Taiwan
| | - Yu-Wen Huang
- Department of Chemistry, National Tsing Hua University, Hsinchu 300, Taiwan
| | - Sen-Lin Tang
- Institute of Oceanography, National Taiwan University, Taipei 106, Taiwan
- Biodiversity Research Center, Academia Sinica, Taipei 115, Taiwan
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7
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Priest T, von Appen WJ, Oldenburg E, Popa O, Torres-Valdés S, Bienhold C, Metfies K, Boulton W, Mock T, Fuchs BM, Amann R, Boetius A, Wietz M. Atlantic water influx and sea-ice cover drive taxonomic and functional shifts in Arctic marine bacterial communities. THE ISME JOURNAL 2023; 17:1612-1625. [PMID: 37422598 PMCID: PMC10504371 DOI: 10.1038/s41396-023-01461-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 06/06/2023] [Accepted: 06/15/2023] [Indexed: 07/10/2023]
Abstract
The Arctic Ocean is experiencing unprecedented changes because of climate warming, necessitating detailed analyses on the ecology and dynamics of biological communities to understand current and future ecosystem shifts. Here, we generated a four-year, high-resolution amplicon dataset along with one annual cycle of PacBio HiFi read metagenomes from the East Greenland Current (EGC), and combined this with datasets spanning different spatiotemporal scales (Tara Arctic and MOSAiC) to assess the impact of Atlantic water influx and sea-ice cover on bacterial communities in the Arctic Ocean. Densely ice-covered polar waters harboured a temporally stable, resident microbiome. Atlantic water influx and reduced sea-ice cover resulted in the dominance of seasonally fluctuating populations, resembling a process of "replacement" through advection, mixing and environmental sorting. We identified bacterial signature populations of distinct environmental regimes, including polar night and high-ice cover, and assessed their ecological roles. Dynamics of signature populations were consistent across the wider Arctic; e.g. those associated with dense ice cover and winter in the EGC were abundant in the central Arctic Ocean in winter. Population- and community-level analyses revealed metabolic distinctions between bacteria affiliated with Arctic and Atlantic conditions; the former with increased potential to use bacterial- and terrestrial-derived substrates or inorganic compounds. Our evidence on bacterial dynamics over spatiotemporal scales provides novel insights into Arctic ecology and indicates a progressing Biological Atlantification of the warming Arctic Ocean, with consequences for food webs and biogeochemical cycles.
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Affiliation(s)
- Taylor Priest
- Max Planck Institute for Marine Microbiology, Bremen, 28359, Germany.
| | - Wilken-Jon von Appen
- Physical Oceanography of the Polar Seas, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, 27570, Germany
| | - Ellen Oldenburg
- Institute for Quantitative and Theoretical Biology, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany
| | - Ovidiu Popa
- Institute for Quantitative and Theoretical Biology, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany
| | - Sinhué Torres-Valdés
- Physical Oceanography of the Polar Seas, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, 27570, Germany
| | - Christina Bienhold
- Max Planck Institute for Marine Microbiology, Bremen, 28359, Germany
- Deep-Sea Ecology and Technology, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, 27570, Germany
| | - Katja Metfies
- Polar Biological Oceanography, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, 27570, Germany
| | - William Boulton
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, United Kingdom
- School of Computing Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, United Kingdom
| | - Thomas Mock
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, United Kingdom
| | - Bernhard M Fuchs
- Max Planck Institute for Marine Microbiology, Bremen, 28359, Germany
| | - Rudolf Amann
- Max Planck Institute for Marine Microbiology, Bremen, 28359, Germany
| | - Antje Boetius
- Max Planck Institute for Marine Microbiology, Bremen, 28359, Germany
- Deep-Sea Ecology and Technology, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, 27570, Germany
- MARUM - Center for Marine Environmental Sciences, University of Bremen, Bremen, 28359, Germany
| | - Matthias Wietz
- Max Planck Institute for Marine Microbiology, Bremen, 28359, Germany.
- Deep-Sea Ecology and Technology, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, 27570, Germany.
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8
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Moeller FU, Herbold CW, Schintlmeister A, Mooshammer M, Motti C, Glasl B, Kitzinger K, Behnam F, Watzka M, Schweder T, Albertsen M, Richter A, Webster NS, Wagner M. Taurine as a key intermediate for host-symbiont interaction in the tropical sponge Ianthella basta. THE ISME JOURNAL 2023; 17:1208-1223. [PMID: 37188915 PMCID: PMC10356861 DOI: 10.1038/s41396-023-01420-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 04/14/2023] [Accepted: 04/20/2023] [Indexed: 05/17/2023]
Abstract
Marine sponges are critical components of marine benthic fauna assemblages, where their filter-feeding and reef-building capabilities provide bentho-pelagic coupling and crucial habitat. As potentially the oldest representation of a metazoan-microbe symbiosis, they also harbor dense, diverse, and species-specific communities of microbes, which are increasingly recognized for their contributions to dissolved organic matter (DOM) processing. Recent omics-based studies of marine sponge microbiomes have proposed numerous pathways of dissolved metabolite exchange between the host and symbionts within the context of the surrounding environment, but few studies have sought to experimentally interrogate these pathways. By using a combination of metaproteogenomics and laboratory incubations coupled with isotope-based functional assays, we showed that the dominant gammaproteobacterial symbiont, 'Candidatus Taurinisymbion ianthellae', residing in the marine sponge, Ianthella basta, expresses a pathway for the import and dissimilation of taurine, a ubiquitously occurring sulfonate metabolite in marine sponges. 'Candidatus Taurinisymbion ianthellae' incorporates taurine-derived carbon and nitrogen while, at the same time, oxidizing the dissimilated sulfite into sulfate for export. Furthermore, we found that taurine-derived ammonia is exported by the symbiont for immediate oxidation by the dominant ammonia-oxidizing thaumarchaeal symbiont, 'Candidatus Nitrosospongia ianthellae'. Metaproteogenomic analyses also suggest that 'Candidatus Taurinisymbion ianthellae' imports DMSP and possesses both pathways for DMSP demethylation and cleavage, enabling it to use this compound as a carbon and sulfur source for biomass, as well as for energy conservation. These results highlight the important role of biogenic sulfur compounds in the interplay between Ianthella basta and its microbial symbionts.
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Affiliation(s)
- Florian U Moeller
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
| | - Craig W Herbold
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
| | - Arno Schintlmeister
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
- Large-Instrument Facility for Environmental and Isotope Mass Spectrometry, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Maria Mooshammer
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
| | - Cherie Motti
- Australian Institute of Marine Science, Townsville, QLD, Australia
| | - Bettina Glasl
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
| | - Katharina Kitzinger
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
| | - Faris Behnam
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
| | - Margarete Watzka
- Centre for Microbiology and Environmental Systems Science, Division of Terrestrial Ecosystem Research, University of Vienna, Vienna, Austria
| | - Thomas Schweder
- Institute of Marine Biotechnology e.V., Greifswald, Germany
- Institute of Pharmacy, Pharmaceutical Biotechnology, University of Greifswald, Greifswald, Germany
| | - Mads Albertsen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Andreas Richter
- Centre for Microbiology and Environmental Systems Science, Division of Terrestrial Ecosystem Research, University of Vienna, Vienna, Austria
| | - Nicole S Webster
- Australian Institute of Marine Science, Townsville, QLD, Australia
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, St Lucia, QLD, Australia
- Australian Antarctic Division, Kingston, TAS, Australia
| | - Michael Wagner
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria.
- Large-Instrument Facility for Environmental and Isotope Mass Spectrometry, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria.
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark.
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9
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Schroer WF, Kepner HE, Uchimiya M, Mejia C, Rodriguez LT, Reisch CR, Moran MA. Functional annotation and importance of marine bacterial transporters of plankton exometabolites. ISME COMMUNICATIONS 2023; 3:37. [PMID: 37185952 PMCID: PMC10130141 DOI: 10.1038/s43705-023-00244-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 04/01/2023] [Accepted: 04/14/2023] [Indexed: 05/17/2023]
Abstract
Metabolite exchange within marine microbial communities transfers carbon and other major elements through global cycles and forms the basis of microbial interactions. Yet lack of gene annotations and concern about the quality of existing ones remain major impediments to revealing currencies of carbon flux. We employed an arrayed mutant library of the marine bacterium Ruegeria pomeroyi DSS-3 to experimentally annotate substrates of organic compound transporter systems, using mutant growth and compound drawdown analyses to link transporters to their cognate substrates. Mutant experiments verified substrates for thirteen R. pomeroyi transporters. Four were previously hypothesized based on gene expression data (taurine, glucose/xylose, isethionate, and cadaverine/putrescine/spermidine); five were previously hypothesized based on homology to experimentally annotated transporters in other bacteria (citrate, glycerol, N-acetylglucosamine, fumarate/malate/succinate, and dimethylsulfoniopropionate); and four had no previous annotations (thymidine, carnitine, cysteate, and 3-hydroxybutyrate). These bring the total number of experimentally-verified organic carbon influx transporters to 18 of 126 in the R. pomeroyi genome. In a longitudinal study of a coastal phytoplankton bloom, expression patterns of the experimentally annotated transporters linked them to different stages of the bloom, and also led to the hypothesis that citrate and 3-hydroxybutyrate were among the most highly available bacterial substrates. Improved functional annotation of the gatekeepers of organic carbon uptake is critical for deciphering carbon flux and fate in microbial ecosystems.
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Affiliation(s)
- William F Schroer
- Department of Marine Sciences, University of Georgia, Athens, GA, 30602, USA
| | - Hannah E Kepner
- Department of Marine Sciences, University of Georgia, Athens, GA, 30602, USA
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, AK, 99775, USA
| | - Mario Uchimiya
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
| | - Catalina Mejia
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, 32611, USA
| | | | - Christopher R Reisch
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, 32611, USA
| | - Mary Ann Moran
- Department of Marine Sciences, University of Georgia, Athens, GA, 30602, USA.
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10
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Barak-Gavish N, Dassa B, Kuhlisch C, Nussbaum I, Brandis A, Rosenberg G, Avraham R, Vardi A. Bacterial lifestyle switch in response to algal metabolites. eLife 2023; 12:e84400. [PMID: 36691727 PMCID: PMC9873259 DOI: 10.7554/elife.84400] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/05/2023] [Indexed: 01/19/2023] Open
Abstract
Unicellular algae, termed phytoplankton, greatly impact the marine environment by serving as the basis of marine food webs and by playing central roles in the biogeochemical cycling of elements. The interactions between phytoplankton and heterotrophic bacteria affect the fitness of both partners. It is becoming increasingly recognized that metabolic exchange determines the nature of such interactions, but the underlying molecular mechanisms remain underexplored. Here, we investigated the molecular and metabolic basis for the bacterial lifestyle switch, from coexistence to pathogenicity, in Sulfitobacter D7 during its interaction with Emiliania huxleyi, a cosmopolitan bloom-forming phytoplankter. To unravel the bacterial lifestyle switch, we analyzed bacterial transcriptomes in response to exudates derived from algae in exponential growth and stationary phase, which supported the Sulfitobacter D7 coexistence and pathogenicity lifestyles, respectively. In pathogenic mode, Sulfitobacter D7 upregulated flagellar motility and diverse transport systems, presumably to maximize assimilation of E. huxleyi-derived metabolites released by algal cells upon cell death. Algal dimethylsulfoniopropionate (DMSP) was a pivotal signaling molecule that mediated the transition between the lifestyles, supporting our previous findings. However, the coexisting and pathogenic lifestyles were evident only in the presence of additional algal metabolites. Specifically, we discovered that algae-produced benzoate promoted the growth of Sulfitobacter D7 and hindered the DMSP-induced lifestyle switch to pathogenicity, demonstrating that benzoate is important for maintaining the coexistence of algae and bacteria. We propose that bacteria can sense the physiological state of the algal host through changes in the metabolic composition, which will determine the bacterial lifestyle during interaction.
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Affiliation(s)
- Noa Barak-Gavish
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Bareket Dassa
- Life Sciences Core Facilities, Weizmann Institute of ScienceRehovotIsrael
| | - Constanze Kuhlisch
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Inbal Nussbaum
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Alexander Brandis
- Life Sciences Core Facilities, Weizmann Institute of ScienceRehovotIsrael
| | - Gili Rosenberg
- Department of Biological Regulation, Weizmann Institute of ScienceRehovotIsrael
| | - Roi Avraham
- Department of Biological Regulation, Weizmann Institute of ScienceRehovotIsrael
| | - Assaf Vardi
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
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11
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Ferrer-González FX, Hamilton M, Smith CB, Schreier JE, Olofsson M, Moran MA. Bacterial transcriptional response to labile exometabolites from photosynthetic picoeukaryote Micromonas commoda. ISME COMMUNICATIONS 2023; 3:5. [PMID: 36690682 PMCID: PMC9870897 DOI: 10.1038/s43705-023-00212-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 12/30/2022] [Accepted: 01/11/2023] [Indexed: 01/24/2023]
Abstract
Dissolved primary production released into seawater by marine phytoplankton is a major source of carbon fueling heterotrophic bacterial production in the ocean. The composition of the organic compounds released by healthy phytoplankton is poorly known and difficult to assess with existing chemical methods. Here, expression of transporter and catabolic genes by three model marine bacteria (Ruegeria pomeroyi DSS-3, Stenotrophomonas sp. SKA14, and Polaribacter dokdonensis MED152) was used as a biological sensor of metabolites released from the picoeukaryote Micromonas commoda RCC299. Bacterial expression responses indicated that the three species together recognized 38 picoeukaryote metabolites. This was consistent with the Micromonas expression of genes for starch metabolism and synthesis of peptidoglycan-like intermediates. A comparison of the hypothesized Micromonas exometabolite pool with that of the diatom Thalassiosira pseudonana CCMP1335, analyzed previously with the same biological sensor method, indicated that both phytoplankton released organic acids, nucleosides, and amino acids, but differed in polysaccharide and organic nitrogen release. Future ocean conditions are expected to favor picoeukaryotic phytoplankton over larger-celled microphytoplankton. Results from this study suggest that such a shift could alter the substrate pool available to heterotrophic bacterioplankton.
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Affiliation(s)
| | - Maria Hamilton
- Department of Marine Sciences, University of Georgia, Athens, GA, 30602, USA
| | - Christa B Smith
- Department of Marine Sciences, University of Georgia, Athens, GA, 30602, USA
| | - Jeremy E Schreier
- Department of Marine Sciences, University of Georgia, Athens, GA, 30602, USA
| | - Malin Olofsson
- Department of Marine Sciences, University of Georgia, Athens, GA, 30602, USA
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, 750 07, Uppsala, Sweden
| | - Mary Ann Moran
- Department of Marine Sciences, University of Georgia, Athens, GA, 30602, USA.
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12
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Pinhassi J, Farnelid H, García SM, Teira E, Galand PE, Obernosterer I, Quince C, Vila-Costa M, Gasol JM, Lundin D, Andersson AF, Labrenz M, Riemann L. Functional responses of key marine bacteria to environmental change – toward genetic counselling for coastal waters. Front Microbiol 2022; 13:869093. [DOI: 10.3389/fmicb.2022.869093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 11/11/2022] [Indexed: 12/04/2022] Open
Abstract
Coastal ecosystems deteriorate globally due to human-induced stress factors, like nutrient loading and pollution. Bacteria are critical to marine ecosystems, e.g., by regulating nutrient cycles, synthesizing vitamins, or degrading pollutants, thereby providing essential ecosystem services ultimately affecting economic activities. Yet, until now bacteria are overlooked both as mediators and indicators of ecosystem health, mainly due to methodological limitations in assessing bacterial ecosystem functions. However, these limitations are largely overcome by the advances in molecular biology and bioinformatics methods for characterizing the genetics that underlie functional traits of key bacterial populations – “key” in providing important ecosystem services, being abundant, or by possessing high metabolic rates. It is therefore timely to analyze and define the functional responses of bacteria to human-induced effects on coastal ecosystem health. We posit that categorizing the responses of key marine bacterial populations to changes in environmental conditions through modern microbial oceanography methods will allow establishing the nascent field of genetic counselling for our coastal waters. This requires systematic field studies of linkages between functional traits of key bacterial populations and their ecosystem functions in coastal seas, complemented with systematic experimental analyses of the responses to different stressors. Research and training in environmental management along with dissemination of results and dialogue with societal actors are equally important to ensure the role of bacteria is understood as fundamentally important for coastal ecosystems. Using the responses of microorganisms as a tool to develop genetic counselling for coastal ecosystems can ultimately allow for integrating bacteria as indicators of environmental change.
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13
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Pontiller B, Martínez-García S, Joglar V, Amnebrink D, Pérez-Martínez C, González JM, Lundin D, Fernández E, Teira E, Pinhassi J. Rapid bacterioplankton transcription cascades regulate organic matter utilization during phytoplankton bloom progression in a coastal upwelling system. THE ISME JOURNAL 2022; 16:2360-2372. [PMID: 35804052 PMCID: PMC9478159 DOI: 10.1038/s41396-022-01273-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 06/01/2022] [Accepted: 06/16/2022] [Indexed: 11/09/2022]
Abstract
Coastal upwelling zones are hotspots of oceanic productivity, driven by phytoplankton photosynthesis. Bacteria, in turn, grow on and are the principal remineralizers of dissolved organic matter (DOM) produced in aquatic ecosystems. However, the molecular processes that key bacterial taxa employ to regulate the turnover of phytoplankton-derived DOM are not well understood. We therefore carried out comparative time-series metatranscriptome analyses of bacterioplankton in the Northwest Iberian upwelling system, using parallel sampling of seawater and mesocosms with in situ-like conditions. The mesocosm experiment uncovered a taxon-specific progression of transcriptional responses from bloom development (characterized by a diverse set of taxa in the orders Cellvibrionales, Rhodobacterales, and Pelagibacterales), over early decay (mainly taxa in the Alteromonadales and Flavobacteriales), to senescence phases (Flavobacteriales and Saprospirales taxa). Pronounced order-specific differences in the transcription of glycoside hydrolases, peptidases, and transporters were found, supporting that functional resource partitioning is dynamically structured by temporal changes in available DOM. In addition, comparative analysis of mesocosm and field samples revealed a high degree of metabolic plasticity in the degradation and uptake of carbohydrates and nitrogen-rich compounds, suggesting these gene systems critically contribute to modulating the stoichiometry of the labile DOM pool. Our findings suggest that cascades of transcriptional responses in gene systems for the utilization of organic matter and nutrients largely shape the fate of organic matter on the time scales typical of upwelling-driven phytoplankton blooms.
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14
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Nikitashina V, Stettin D, Pohnert G. Metabolic adaptation of diatoms to hypersalinity. PHYTOCHEMISTRY 2022; 201:113267. [PMID: 35671808 DOI: 10.1016/j.phytochem.2022.113267] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/20/2022] [Accepted: 05/29/2022] [Indexed: 06/15/2023]
Abstract
Microalgae are important primary producers and form the basis for the marine food web. As global climate changes, so do salinity levels that algae are exposed to. A metabolic response of algal cells partly alleviates the resulting osmotic stress. Some metabolites involved in the response are well studied, but the full metabolic implications of adaptation remain unclear. Improved analytical methodology provides an opportunity for additional insight. We can now follow responses to stress in major parts of the metabolome and derive comprehensive charts of the resulting metabolic re-wiring. In this study, we subjected three species of diatoms to high salinity conditions and compared their metabolome to controls in an untargeted manner. The three well-investigated species with sequenced genomes Phaeodactylum tricornutum, Thalassiosira pseudonana, and Skeletonema marinoi were selected for our survey. The microalgae react to salinity stress with common adaptations in the metabolome by amino acid up-regulation, production of saccharides, and inositols. But also species-specific dysregulation of metabolites is common. Several metabolites previously not connected with osmotic stress reactions are identified, including 4-hydroxyproline, pipecolinic acid, myo-inositol, threonic acid, and acylcarnitines. This expands our knowledge about osmoadaptation and calls for further functional characterization of metabolites and pathways in algal stress physiology.
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Affiliation(s)
- Vera Nikitashina
- Institute for Inorganic and Analytical Chemistry, Bioorganic Analytics, Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Daniel Stettin
- Institute for Inorganic and Analytical Chemistry, Bioorganic Analytics, Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Georg Pohnert
- Institute for Inorganic and Analytical Chemistry, Bioorganic Analytics, Friedrich Schiller University Jena, 07743, Jena, Germany.
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15
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Reinl KL, Harris TD, Elfferich I, Coker A, Zhan Q, De Senerpont Domis LN, Morales-Williams AM, Bhattacharya R, Grossart HP, North RL, Sweetman JN. The role of organic nutrients in structuring freshwater phytoplankton communities in a rapidly changing world. WATER RESEARCH 2022; 219:118573. [PMID: 35643062 DOI: 10.1016/j.watres.2022.118573] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 04/27/2022] [Accepted: 05/07/2022] [Indexed: 06/15/2023]
Abstract
Carbon, nitrogen, and phosphorus are critical macroelements in freshwater systems. Historically, researchers and managers have focused on inorganic forms, based on the premise that the organic pool was not available for direct uptake by phytoplankton. We now know that phytoplankton can tap the organic nutrient pool through a number of mechanisms including direct uptake, enzymatic hydrolysis, mixotrophy, and through symbiotic relationships with microbial communities. In this review, we explore these mechanisms considering current and projected future anthropogenically-driven changes to freshwater systems. In particular, we focus on how naturally- and anthropogenically- derived organic nutrients can influence phytoplankton community structure. We also synthesize knowledge gaps regarding phytoplankton physiology and the potential challenges of nutrient management in an organically dynamic and anthropogenically modified world. Our review provides a basis for exploring these topics and suggests several avenues for future work on the relation between organic nutrients and eutrophication and their ecological implications in freshwater systems.
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Affiliation(s)
- Kaitlin L Reinl
- Lake Superior National Estuarine Research Reserve, University of Wisconsin-Madison Division of Extension, 14 Marina Drive, Superior, Wisconsin 54880, US; University of Wisconsin-Madison, Center for Limnology, 608 N. Park St., Madison, WI, US; University of Minnesota-Duluth, Large Lakes Observatory, 2205 E. 5th St., Duluth, MN, US.
| | - Ted D Harris
- Kansas Biological Survey and Center for Ecological Research, 2101 Constant Ave., Lawrence, KS, US
| | - Inge Elfferich
- Cardiff University, Earth and Environmental Sciences, Main Building, Park Place CF10 3AT, Cardiff, UK
| | - Ayooluwateso Coker
- University of Minnesota-Duluth, Large Lakes Observatory, 2205 E. 5th St., Duluth, MN, US
| | - Qing Zhan
- Netherlands Institute of Ecology, Dept. of Aquatic Ecology, Droevendaalsesteeg 10, Wageningen, NL
| | | | - Ana M Morales-Williams
- University of Vermont, Rubenstein School of Environment and Natural Resources, 81 Carrigan Drive, Burlington, VT, US
| | - Ruchi Bhattacharya
- University of Waterloo, Department of Earth and Environmental Sciences, 200 University Ave., N2L 1V6, Waterloo, ON, CA
| | - Hans-Peter Grossart
- Leibniz Institute for Freshwater Ecology and Inland Fisheries (IGB), Dept. Plankton and Microbial Ecology, Zur alten Fischerhuette 2, D-16775 Stechlin, DE; Potsdam University, Institute of Biochemistry and Biology, Maulbeerallee 2, 14469 Potsdam
| | - Rebecca L North
- University of Missouri-Columbia, School of Natural Resources, 303L Anheuser Busch Natural Resource Building, Columbia, MO, US
| | - Jon N Sweetman
- Pennsylvania State University, Ecological Science and Management, 457 Agriculture Sciences and Industries Building, State College, PA, US
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16
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Srinivas S, Berger M, Brinkhoff T, Niggemann J. Impact of Quorum Sensing and Tropodithietic Acid Production on the Exometabolome of Phaeobacter inhibens. Front Microbiol 2022; 13:917969. [PMID: 35801100 PMCID: PMC9253639 DOI: 10.3389/fmicb.2022.917969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 06/03/2022] [Indexed: 11/29/2022] Open
Abstract
Microbial interactions shape ecosystem diversity and chemistry through production and exchange of organic compounds, but the impact of regulatory mechanisms on production and release of these exometabolites is largely unknown. We studied the extent and nature of impact of two signaling molecules, tropodithietic acid (TDA) and the quorum sensing molecule acyl homoserine lactone (AHL) on the exometabolome of the model bacterium Phaeobacter inhibens DSM 17395, a member of the ubiquitous marine Roseobacter group. Exometabolomes of the wild type, a TDA and a QS (AHL-regulator) negative mutant were analyzed via Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Based on a total of 996 reproducibly detected molecular masses, exometabolomes of the TDA and QS negative mutant were ∼70% dissimilar to each other, and ∼90 and ∼60% dissimilar, respectively, to that of the wild type. Moreover, at any sampled growth phase, 40–60% of masses detected in any individual exometabolome were unique to that strain, while only 10–12% constituted a shared “core exometabolome.” Putative annotation revealed exometabolites of ecological relevance such as vitamins, amino acids, auxins, siderophore components and signaling compounds with different occurrence patterns in the exometabolomes of the three strains. Thus, this study demonstrates that signaling molecules, such as AHL and TDA, extensively impact the composition of bacterial exometabolomes with potential consequences for species interactions in microbial communities.
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Affiliation(s)
- Sujatha Srinivas
- Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany
| | - Martine Berger
- Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany
| | - Thorsten Brinkhoff
- Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany
| | - Jutta Niggemann
- Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany
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17
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Uchimiya M, Schroer W, Olofsson M, Edison AS, Moran MA. Diel investments in metabolite production and consumption in a model microbial system. THE ISME JOURNAL 2022; 16:1306-1317. [PMID: 34921302 PMCID: PMC9038784 DOI: 10.1038/s41396-021-01172-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 11/27/2021] [Accepted: 12/03/2021] [Indexed: 12/01/2022]
Abstract
Organic carbon transfer between surface ocean photosynthetic and heterotrophic microbes is a central but poorly understood process in the global carbon cycle. In a model community in which diatom extracellular release of organic molecules sustained growth of a co-cultured bacterium, we determined quantitative changes in the diatom endometabolome and the bacterial uptake transcriptome over two diel cycles. Of the nuclear magnetic resonance (NMR) peaks in the diatom endometabolites, 38% had diel patterns with noon or mid-afternoon maxima; the remaining either increased (36%) or decreased (26%) through time. Of the genes in the bacterial uptake transcriptome, 94% had a diel pattern with a noon maximum; the remaining decreased over time (6%). Eight diatom endometabolites identified with high confidence were matched to the bacterial genes mediating their utilization. Modeling of these coupled inventories with only diffusion-based phytoplankton extracellular release could not reproduce all the patterns. Addition of active release mechanisms for physiological balance and bacterial recognition significantly improved model performance. Estimates of phytoplankton extracellular release range from only a few percent to nearly half of annual net primary production. Improved understanding of the factors that influence metabolite release and consumption by surface ocean microbes will better constrain this globally significant carbon flux.
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Affiliation(s)
- Mario Uchimiya
- Department of Marine Sciences, University of Georgia, Athens, GA, 30602, US
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, US
| | - William Schroer
- Department of Marine Sciences, University of Georgia, Athens, GA, 30602, US
| | - Malin Olofsson
- Department of Marine Sciences, University of Georgia, Athens, GA, 30602, US
- Swedish University of Agricultural Sciences, Department of Aquatic Sciences and Assessment, Uppsala, Sweden
| | - Arthur S Edison
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, US
| | - Mary Ann Moran
- Department of Marine Sciences, University of Georgia, Athens, GA, 30602, US.
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18
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Raina JB, Lambert BS, Parks DH, Rinke C, Siboni N, Bramucci A, Ostrowski M, Signal B, Lutz A, Mendis H, Rubino F, Fernandez VI, Stocker R, Hugenholtz P, Tyson GW, Seymour JR. Chemotaxis shapes the microscale organization of the ocean's microbiome. Nature 2022; 605:132-138. [PMID: 35444277 DOI: 10.1038/s41586-022-04614-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 03/04/2022] [Indexed: 01/04/2023]
Abstract
The capacity of planktonic marine microorganisms to actively seek out and exploit microscale chemical hotspots has been widely theorized to affect ocean-basin scale biogeochemistry1-3, but has never been examined comprehensively in situ among natural microbial communities. Here, using a field-based microfluidic platform to quantify the behavioural responses of marine bacteria and archaea, we observed significant levels of chemotaxis towards microscale hotspots of phytoplankton-derived dissolved organic matter (DOM) at a coastal field site across multiple deployments, spanning several months. Microscale metagenomics revealed that a wide diversity of marine prokaryotes, spanning 27 bacterial and 2 archaeal phyla, displayed chemotaxis towards microscale patches of DOM derived from ten globally distributed phytoplankton species. The distinct DOM composition of each phytoplankton species attracted phylogenetically and functionally discrete populations of bacteria and archaea, with 54% of chemotactic prokaryotes displaying highly specific responses to the DOM derived from only one or two phytoplankton species. Prokaryotes exhibiting chemotaxis towards phytoplankton-derived compounds were significantly enriched in the capacity to transport and metabolize specific phytoplankton-derived chemicals, and displayed enrichment in functions conducive to symbiotic relationships, including genes involved in the production of siderophores, B vitamins and growth-promoting hormones. Our findings demonstrate that the swimming behaviour of natural prokaryotic assemblages is governed by specific chemical cues, which dictate important biogeochemical transformation processes and the establishment of ecological interactions that structure the base of the marine food web.
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Affiliation(s)
- Jean-Baptiste Raina
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, New South Wales, Australia.
| | - Bennett S Lambert
- Ralph M. Parsons Laboratory, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.,Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, MA, USA.,Center for Environmental Genomics, School of Oceanography, University of Washington, Seattle, WA, USA.,Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
| | - Donovan H Parks
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Christian Rinke
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Nachshon Siboni
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, New South Wales, Australia
| | - Anna Bramucci
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, New South Wales, Australia
| | - Martin Ostrowski
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, New South Wales, Australia
| | - Brandon Signal
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, New South Wales, Australia
| | - Adrian Lutz
- Metabolomics Australia, Bio21 Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - Himasha Mendis
- Metabolomics Australia, Bio21 Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - Francesco Rubino
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Vicente I Fernandez
- Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
| | - Roman Stocker
- Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
| | - Philip Hugenholtz
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Gene W Tyson
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia.,Centre for Microbiome Research, School of Biomedical Sciences, Translational Research Institute, Queensland University of Technology, Woolloongabba, Queensland, Australia
| | - Justin R Seymour
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, New South Wales, Australia.
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19
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Moran MA, Kujawinski EB, Schroer WF, Amin SA, Bates NR, Bertrand EM, Braakman R, Brown CT, Covert MW, Doney SC, Dyhrman ST, Edison AS, Eren AM, Levine NM, Li L, Ross AC, Saito MA, Santoro AE, Segrè D, Shade A, Sullivan MB, Vardi A. Microbial metabolites in the marine carbon cycle. Nat Microbiol 2022; 7:508-523. [PMID: 35365785 DOI: 10.1038/s41564-022-01090-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 02/23/2022] [Indexed: 01/08/2023]
Abstract
One-quarter of photosynthesis-derived carbon on Earth rapidly cycles through a set of short-lived seawater metabolites that are generated from the activities of marine phytoplankton, bacteria, grazers and viruses. Here we discuss the sources of microbial metabolites in the surface ocean, their roles in ecology and biogeochemistry, and approaches that can be used to analyse them from chemistry, biology, modelling and data science. Although microbial-derived metabolites account for only a minor fraction of the total reservoir of marine dissolved organic carbon, their flux and fate underpins the central role of the ocean in sustaining life on Earth.
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Affiliation(s)
- Mary Ann Moran
- Department of Marine Sciences, University of Georgia, Athens, GA, USA.
| | - Elizabeth B Kujawinski
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, USA.
| | - William F Schroer
- Department of Marine Sciences, University of Georgia, Athens, GA, USA
| | - Shady A Amin
- Division of Science, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Nicholas R Bates
- Bermuda Institute of Ocean Sciences, St George's, Bermuda.,School of Ocean and Earth Sciences, University of Southampton, Southampton, UK
| | - Erin M Bertrand
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Rogier Braakman
- Departments of Earth, Atmospheric and Planetary Sciences, and Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - C Titus Brown
- Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA
| | - Markus W Covert
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Scott C Doney
- Department of Environmental Sciences, University of Virginia, Charlottesville, VA, USA
| | - Sonya T Dyhrman
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA.,Department of Earth and Environmental Science, Columbia University, Palisades, NY, USA
| | - Arthur S Edison
- Departments of Biochemistry and Genetics, Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - A Murat Eren
- Josephine Bay Paul Center, Marine Biological Laboratory, Woods Hole, MA, USA.,Helmholtz-Institute for Functional Marine Biodiversity (HIFMB), University of Oldenburg, Oldenburg, Germany
| | - Naomi M Levine
- Marine and Environmental Biology, Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Liang Li
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Avena C Ross
- Department of Chemistry, Queen's University, Kingston, Ontario, Canada
| | - Mak A Saito
- Department of Marine Sciences, University of Georgia, Athens, GA, USA
| | - Alyson E Santoro
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA, USA
| | - Daniel Segrè
- Department of Biology and Bioinformatics Program, Boston University, Boston, MA, USA
| | - Ashley Shade
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
| | - Matthew B Sullivan
- Departments of Microbiology and Civil, Environmental, and Geodetic Engineering, and Center of Microbiome Science, The Ohio State University, Columbus, OH, USA
| | - Assaf Vardi
- Department of Plant and Environmental Sciences, The Weizmann Institute of Science, Rehovot, Israel
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20
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Olofsson M, Ferrer-González FX, Uchimiya M, Schreier JE, Holderman NR, Smith CB, Edison AS, Moran MA. Growth-stage-related shifts in diatom endometabolome composition set the stage for bacterial heterotrophy. ISME COMMUNICATIONS 2022; 2:28. [PMID: 37938663 PMCID: PMC9723723 DOI: 10.1038/s43705-022-00116-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 02/25/2022] [Accepted: 03/07/2022] [Indexed: 05/28/2023]
Abstract
Phytoplankton-derived metabolites fuel a large fraction of heterotrophic bacterial production in the global ocean, yet methodological challenges have limited our understanding of the organic molecules transferred between these microbial groups. In an experimental bloom study consisting of three heterotrophic marine bacteria growing together with the diatom Thalassiosira pseudonana, we concurrently measured diatom endometabolites (i.e., potential exometabolite supply) by nuclear magnetic resonance (NMR) spectroscopy and bacterial gene expression (i.e., potential exometabolite uptake) by metatranscriptomic sequencing. Twenty-two diatom endometabolites were annotated, with nine increasing in internal concentration in the late stage of the bloom, eight decreasing, and five showing no variation through the bloom progression. Some metabolite changes could be linked to shifts in diatom gene expression, as well as to shifts in bacterial community composition and their expression of substrate uptake and catabolism genes. Yet an overall low match indicated that endometabolome concentration was not a good predictor of exometabolite availability, and that complex physiological and ecological interactions underlie metabolite exchange. Six diatom endometabolites accumulated to higher concentrations in the bacterial co-cultures compared to axenic cultures, suggesting a bacterial influence on rates of synthesis or release of glutamate, arginine, leucine, 2,3-dihydroxypropane-1-sulfonate, glucose, and glycerol-3-phosphate. Better understanding of phytoplankton metabolite production, release, and transfer to assembled bacterial communities is key to untangling this nearly invisible yet pivotal step in ocean carbon cycling.
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Affiliation(s)
- Malin Olofsson
- Department of Marine Sciences, University of Georgia, Athens, GA, 30602, USA
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, 750 57, Uppsala, Sweden
| | | | - Mario Uchimiya
- Department of Marine Sciences, University of Georgia, Athens, GA, 30602, USA
- Department of Biochemistry and Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
| | - Jeremy E Schreier
- Department of Marine Sciences, University of Georgia, Athens, GA, 30602, USA
| | - Nicole R Holderman
- Department of Biochemistry and Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
| | - Christa B Smith
- Department of Marine Sciences, University of Georgia, Athens, GA, 30602, USA
| | - Arthur S Edison
- Department of Biochemistry and Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
| | - Mary Ann Moran
- Department of Marine Sciences, University of Georgia, Athens, GA, 30602, USA.
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21
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Hermann L, Dempwolff F, Steinchen W, Freibert SA, Smits SHJ, Seubert A, Bremer E. The MocR/GabR Ectoine and Hydroxyectoine Catabolism Regulator EnuR: Inducer and DNA Binding. Front Microbiol 2022; 12:764731. [PMID: 35003002 PMCID: PMC8739950 DOI: 10.3389/fmicb.2021.764731] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 12/01/2021] [Indexed: 11/26/2022] Open
Abstract
The compatible solutes ectoine and 5-hydroxyectoine are widely synthesized by bacteria as osmostress protectants. These nitrogen-rich tetrahydropyrimidines can also be exploited as nutrients by microorganisms. Many ectoine/5-hydroxyectoine catabolic gene clusters are associated with a regulatory gene (enuR: ectoine nutrient utilization regulator) encoding a repressor protein belonging to the MocR/GabR sub-family of GntR-type transcription factors. Focusing on EnuR from the marine bacterium Ruegeria pomeroyi, we show that the dimerization of EnuR is mediated by its aminotransferase domain. This domain can fold independently from its amino-terminal DNA reading head and can incorporate pyridoxal-5′-phosphate (PLP) as cofactor. The covalent attachment of PLP to residue Lys302 of EnuR was proven by mass-spectrometry. PLP interacts with system-specific, ectoine and 5-hydroxyectoine-derived inducers: alpha-acetyldiaminobutyric acid (alpha-ADABA), and hydroxy-alpha-acetyldiaminobutyric acid (hydroxy-alpha-ADABA), respectively. These inducers are generated in cells actively growing with ectoines as sole carbon and nitrogen sources, by the EutD hydrolase and targeted metabolic analysis allowed their detection. EnuR binds these effector molecules with affinities in the low micro-molar range. Studies addressing the evolutionary conservation of EnuR, modelling of the EnuR structure, and docking experiments with the inducers provide an initial view into the cofactor and effector binding cavity. In this cavity, the two high-affinity inducers for EnuR, alpha-ADABA and hydroxy-alpha-ADABA, are positioned such that their respective primary nitrogen group can chemically interact with PLP. Purified EnuR bound with micro-molar affinity to a 48 base pair DNA fragment containing the sigma-70 type substrate-inducible promoter for the ectoine/5-hydroxyectoine importer and catabolic gene cluster. Consistent with the function of EnuR as a repressor, the core elements of the promoter overlap with two predicted EnuR operators. Our data lend themselves to a straightforward regulatory model for the initial encounter of EnuR-possessing ectoine/5-hydroxyectoine consumers with environmental ectoines and for the situation when the external supply of these compounds has been exhausted by catabolism.
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Affiliation(s)
- Lucas Hermann
- Faculty of Biology, Philipps-University Marburg, Marburg, Germany.,Department of Biochemistry and Synthetic Metabolism, Max-Planck-Institute for Terrestrial Microbiology, Marburg, Germany
| | - Felix Dempwolff
- SYNMIKRO Research Center, Philipps-University Marburg, Marburg, Germany
| | - Wieland Steinchen
- SYNMIKRO Research Center, Philipps-University Marburg, Marburg, Germany
| | - Sven-Andreas Freibert
- Department of Medicine, Institute for Cytobiology and Cytopathology, and SYNMIKRO Research Center, Philipps-University Marburg, Marburg, Germany
| | - Sander H J Smits
- Institute of Biochemistry, Heinrich-Heine-University, Düsseldorf, Germany.,Center for Structural Studies (CSS), Faculty of Biochemistry, Heinrich-Heine-University, Düsseldorf, Germany
| | - Andreas Seubert
- Faculty of Chemistry, Philipps-University Marburg, Marburg, Germany
| | - Erhard Bremer
- Faculty of Biology, Philipps-University Marburg, Marburg, Germany.,SYNMIKRO Research Center, Philipps-University Marburg, Marburg, Germany
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22
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Deng Y, Vallet M, Pohnert G. Temporal and Spatial Signaling Mediating the Balance of the Plankton Microbiome. ANNUAL REVIEW OF MARINE SCIENCE 2022; 14:239-260. [PMID: 34437810 DOI: 10.1146/annurev-marine-042021-012353] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The annual patterns of plankton succession in the ocean determine ecological and biogeochemical cycles. The temporally fluctuating interplay between photosynthetic eukaryotes and the associated microbiota balances the composition of aquatic planktonic ecosystems. In addition to nutrients and abiotic factors, chemical signaling determines the outcome of interactions between phytoplankton and their associated microbiomes. Chemical mediators control essential processes, such as the development of key morphological, physiological, behavioral, and life-history traits during algal growth. These molecules thus impact species succession and community composition across time and space in processes that are highlighted in this review. We focus on spatial, seasonal, and physiological dynamics that occur during the early association of algae with bacteria, the exponential growth of a bloom, and its decline and recycling. We also discuss how patterns from field data and global surveys might be linked to the actions of metabolic markers in natural phytoplankton assemblages.
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Affiliation(s)
- Yun Deng
- Institute for Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, 07743 Jena, Germany;
| | - Marine Vallet
- Research Group Phytoplankton Community Interactions, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Georg Pohnert
- Institute for Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, 07743 Jena, Germany;
- Research Group Phytoplankton Community Interactions, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
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23
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OUP accepted manuscript. FEMS Microbiol Rev 2022; 46:6585976. [DOI: 10.1093/femsre/fuac020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 05/05/2022] [Accepted: 05/06/2022] [Indexed: 11/13/2022] Open
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24
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Chen X, Liu L, Gao X, Dai X, Han Y, Chen Q, Tang K. Metabolism of chiral sulfonate compound 2,3-dihydroxypropane-1-sulfonate (DHPS) by Roseobacter bacteria in marine environment. ENVIRONMENT INTERNATIONAL 2021; 157:106829. [PMID: 34425483 DOI: 10.1016/j.envint.2021.106829] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 08/12/2021] [Accepted: 08/13/2021] [Indexed: 06/13/2023]
Abstract
The sulfonate compound 2,3-dihydroxypropane-1-sulfonate (DHPS) is one of the most abundant organic sulfur compounds in the biosphere. DHPS derived from dietary intake could be transformed into sulfide by intestinal microbiota and thus impacts human health. However, little is known about its sulfur transformation and subsequent impacts in marine environment. In this study, laboratory-culturing was combined with targeted metabolomic, chemical fluorescence probing, and comparative proteomic methods to examine the bioavailability of chiral DHPS (R and S isomers) for bacteria belonging to the marine Roseobacter clade. The metabolic potential of DHPS in bacteria was further assessed based on genomic analysis. Roseobacter members Ruegeria pomeroyi DSS-3, Dinoroseobacter shibae DFL 12, and Roseobacter denitrificans OCh 114 could utilize chiral DHPS for growth, producing sulfite. They all contained a similar gene cluster for DHPS metabolism but differed in the genes encoding enzymes for desulfonation. There was no significant difference in the growth rate and DHPS consumption rate for R. pomeroyi DSS-3 between R- and S-DHPS cultures, with few proteins expressed differentially were found. Proteomic data suggested that a series of hydrogenases oxidized DHPS, after which desulfonation could proceed via three distinct enzymatic pathways. Strain R. pomeroyi DSS-3 completed the desulfonation via L-cysteate sulfo-lyase, while D. shibae DFL 12 and R. denitrificans OCh 114 primarily utilized sulfolactate sulfo-lyase, and sulfopyruvate decarboxylase followed by sulfoacetaldehyde acetyltransferase, respectively, to complete desulfonation releasing the sulfonate-moiety. The sulfite could be further oxidized or incorporated into sulfate assimilation, indicated by the proteomic data. Furthermore, DHPS metabolic pathways were found primarily in marine bacterial groups, including the majority of sequenced Roseobacter genomes. Our results suggest that chiral DHPS, as a vital reduced sulfur reservoir, could be metabolized by marine bacteria, providing a resource for bacterial growth, rather than acting as a source of toxic sulfide within the marine ecosystem.
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Affiliation(s)
- Xiaofeng Chen
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Science, Xiamen University, Xiamen 361102, Fujian, PR China
| | - Le Liu
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Science, Xiamen University, Xiamen 361102, Fujian, PR China
| | - Xiang Gao
- School of Pharmaceutical Sciences, Fujian Provincial Key Laboratory of Innovative Drug Target Research, Xiamen University, Xiamen 361102, Fujian, PR China
| | - Xi Dai
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Science, Xiamen University, Xiamen 361102, Fujian, PR China
| | - Yu Han
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Science, Xiamen University, Xiamen 361102, Fujian, PR China
| | - Quanrui Chen
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Science, Xiamen University, Xiamen 361102, Fujian, PR China
| | - Kai Tang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Science, Xiamen University, Xiamen 361102, Fujian, PR China.
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25
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Daly G, Perrin E, Viti C, Fondi M, Adessi A. Scaling down the microbial loop: data-driven modelling of growth interactions in a diatom-bacterium co-culture. ENVIRONMENTAL MICROBIOLOGY REPORTS 2021; 13:945-954. [PMID: 34541831 PMCID: PMC9293018 DOI: 10.1111/1758-2229.13010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 09/01/2021] [Accepted: 09/03/2021] [Indexed: 06/13/2023]
Abstract
An intricate set of interactions characterizes marine ecosystems. One of the most important is represented by the microbial loop, which includes the exchange of dissolved organic matter (DOM) from phototrophic organisms to heterotrophic bacteria. Here, it can be used as the major carbon and energy source. This interaction is one of the foundations of the entire ocean food-web. The carbon fixed by phytoplankton can be redirected to bacteria in two main ways; either (i) bacteria feed on dead phytoplankton cells or (ii) DOM is actively released by phytoplankton (a process resulting in up to 50% of the fixed carbon leaving the cell). Here, we have set up a co-culture of the diatom Phaeodactylum tricornutum and the chemoheterotrophic bacterium Pseudoalteromonas haloplanktis TAC125 and used this system to study the interactions between these two representatives of the microbial loop. We show that the bacterium can thrive on diatom-derived carbon and that this growth can be sustained by both diatom dead cells and diatom-released compounds. These observations were formalized in a network of putative interactions between P. tricornutum and P. haloplanktis and implemented in a model that reproduces the observed co-culture dynamics, revealing an overall accuracy of our hypotheses in explaining the experimental data.
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Affiliation(s)
- Giulia Daly
- Department of Agriculture, Food, Environment and ForestryUniversity of Florence, Piazzale delle CascineFlorence18Italy
| | - Elena Perrin
- Department of BiologyUniversity of FlorenceVia Madonna del Piano 6, Sesto F.no, FlorenceItaly
| | - Carlo Viti
- Department of Agriculture, Food, Environment and ForestryUniversity of Florence, Piazzale delle CascineFlorence18Italy
| | - Marco Fondi
- Department of BiologyUniversity of FlorenceVia Madonna del Piano 6, Sesto F.no, FlorenceItaly
- Centro Interdipartimentale per lo Studio delle Dinamiche ComplesseUniversity of FlorenceFlorenceItaly
| | - Alessandra Adessi
- Department of Agriculture, Food, Environment and ForestryUniversity of Florence, Piazzale delle CascineFlorence18Italy
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26
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Kieft B, Li Z, Bryson S, Hettich RL, Pan C, Mayali X, Mueller RS. Phytoplankton exudates and lysates support distinct microbial consortia with specialized metabolic and ecophysiological traits. Proc Natl Acad Sci U S A 2021; 118:e2101178118. [PMID: 34620710 PMCID: PMC8521717 DOI: 10.1073/pnas.2101178118] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/09/2021] [Indexed: 11/18/2022] Open
Abstract
Blooms of marine phytoplankton fix complex pools of dissolved organic matter (DOM) that are thought to be partitioned among hundreds of heterotrophic microbes at the base of the food web. While the relationship between microbial consumers and phytoplankton DOM is a key component of marine carbon cycling, microbial loop metabolism is largely understood from model organisms and substrates. Here, we took an untargeted approach to measure and analyze partitioning of four distinct phytoplankton-derived DOM pools among heterotrophic populations in a natural microbial community using a combination of ecogenomics, stable isotope probing (SIP), and proteomics. Each 13C-labeled exudate or lysate from a diatom or a picocyanobacterium was preferentially assimilated by different heterotrophic taxa with specialized metabolic and physiological adaptations. Bacteroidetes populations, with their unique high-molecular-weight transporters, were superior competitors for DOM derived from diatom cell lysis, rapidly increasing growth rates and ribosomal protein expression to produce new relatively high C:N biomass. Proteobacteria responses varied, with relatively low levels of assimilation by Gammaproteobacteria populations, while copiotrophic Alphaproteobacteria such as the Roseobacter clade, with their diverse array of ABC- and TRAP-type transporters to scavenge monomers and nitrogen-rich metabolites, accounted for nearly all cyanobacteria exudate assimilation and produced new relatively low C:N biomass. Carbon assimilation rates calculated from SIP data show that exudate and lysate from two common marine phytoplankton are being used by taxonomically distinct sets of heterotrophic populations with unique metabolic adaptations, providing a deeper mechanistic understanding of consumer succession and carbon use during marine bloom events.
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Affiliation(s)
- Brandon Kieft
- Department of Microbiology, Oregon State University, Corvallis, OR 97331;
| | - Zhou Li
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830
- Graduate School of Genome Science and Technology, The University of Tennessee, Knoxville, TN 37996
| | - Samuel Bryson
- Department of Microbiology, Oregon State University, Corvallis, OR 97331
- Department of Civil & Environmental Engineering, The University of Washington, Seattle, WA 98195
| | - Robert L Hettich
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830
| | - Chongle Pan
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830
- Graduate School of Genome Science and Technology, The University of Tennessee, Knoxville, TN 37996
- Department of Microbiology and Plant Microbiology, University of Oklahoma, Norman, OK 73019
| | - Xavier Mayali
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550
| | - Ryan S Mueller
- Department of Microbiology, Oregon State University, Corvallis, OR 97331;
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27
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Hoke AK, Reynoso G, Smith MR, Gardner MI, Lockwood DJ, Gilbert NE, Wilhelm SW, Becker IR, Brennan GJ, Crider KE, Farnan SR, Mendoza V, Poole AC, Zimmerman ZP, Utz LK, Wurch LL, Steffen MM. Genomic signatures of Lake Erie bacteria suggest interaction in the Microcystis phycosphere. PLoS One 2021; 16:e0257017. [PMID: 34550975 PMCID: PMC8457463 DOI: 10.1371/journal.pone.0257017] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 08/20/2021] [Indexed: 11/18/2022] Open
Abstract
Microbial interactions in harmful algal bloom (HAB) communities have been examined in marine systems, but are poorly studied in fresh waters. To investigate HAB-microbe interactions, we isolated bacteria with close associations to bloom-forming cyanobacteria, Microcystis spp., during a 2017 bloom in the western basin of Lake Erie. The genomes of five isolates (Exiguobacterium sp. JMULE1, Enterobacter sp. JMULE2, Deinococcus sp. JMULE3, Paenibacillus sp. JMULE4, and Acidovorax sp. JMULE5.) were sequenced on a PacBio Sequel system. These genomes ranged in size from 3.1 Mbp (Exiguobacterium sp. JMULE1) to 5.7 Mbp (Enterobacter sp. JMULE2). The genomes were analyzed for genes relating to critical metabolic functions, including nitrogen reduction and carbon utilization. All five of the sequenced genomes contained genes that could be used in potential signaling and nutrient exchange between the bacteria and cyanobacteria such as Microcystis. Gene expression signatures of algal-derived carbon utilization for two isolates were identified in Microcystis blooms in Lake Erie and Lake Tai (Taihu) at low levels, suggesting these organisms are active and may have a functional role during Microcystis blooms in aggregates, but were largely missing from whole water samples. These findings build on the growing evidence that the bacterial microbiome associated with bloom-forming algae have the functional potential to contribute to nutrient exchange within bloom communities and interact with important bloom formers like Microcystis.
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Affiliation(s)
- Alexa K. Hoke
- James Madison University, Harrisonburg, VA, United States of America
| | - Guadalupe Reynoso
- James Madison University, Harrisonburg, VA, United States of America
- Virginia Tech, Blacksburg, VA, United States of America
| | - Morgan R. Smith
- James Madison University, Harrisonburg, VA, United States of America
- Texas A&M University, College Station, TX, United States of America
| | - Malia I. Gardner
- James Madison University, Harrisonburg, VA, United States of America
| | | | - Naomi E. Gilbert
- James Madison University, Harrisonburg, VA, United States of America
- University of Tennessee, Knoxville, TN, United States of America
| | | | | | - Grant J. Brennan
- James Madison University, Harrisonburg, VA, United States of America
| | | | - Shannon R. Farnan
- James Madison University, Harrisonburg, VA, United States of America
| | - Victoria Mendoza
- James Madison University, Harrisonburg, VA, United States of America
| | - Alison C. Poole
- James Madison University, Harrisonburg, VA, United States of America
| | | | - Lucy K. Utz
- James Madison University, Harrisonburg, VA, United States of America
| | - Louie L. Wurch
- James Madison University, Harrisonburg, VA, United States of America
| | - Morgan M. Steffen
- James Madison University, Harrisonburg, VA, United States of America
- * E-mail:
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28
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Conover AE, Morando M, Zhao Y, Semones J, Hutchins DA, Webb EA. Alphaproteobacteria facilitate Trichodesmium community trimethylamine utilization. Environ Microbiol 2021; 23:6798-6810. [PMID: 34519133 DOI: 10.1111/1462-2920.15773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 08/26/2021] [Accepted: 09/09/2021] [Indexed: 11/28/2022]
Abstract
In the surface waters of the warm oligotrophic ocean, filaments and aggregated colonies of the nitrogen (N)-fixing cyanobacterium Trichodesmium create microscale nutrient-rich oases. These hotspots fuel primary productivity and harbour a diverse consortium of heterotrophs. Interactions with associated microbiota can affect the physiology of Trichodesmium, often in ways that have been predicted to support its growth. Recently, it was found that trimethylamine (TMA), a globally abundant organic N compound, inhibits N2 fixation in cultures of Trichodesmium without impairing growth rate, suggesting that Trichodesmium can use TMA as an alternate N source. In this study, 15 N-TMA DNA stable isotope probing (SIP) of a Trichodesmium enrichment was employed to further investigate TMA metabolism and determine whether TMA-N is incorporated directly or secondarily via cross-feeding facilitated by microbial associates. Herein, we identify two members of the marine Roseobacter clade (MRC) of Alphaproteobacteria as the likely metabolizers of TMA and provide genomic evidence that they converted TMA into a more readily available form of N, e.g., ammonium (NH4 + ), which was subsequently used by Trichodesmium and the rest of the community. The results implicate microbiome-mediated carbon (C) and N transformations in modulating N2 fixation and thus highlight the involvement of host-associated heterotrophs in global biogeochemical cycling.
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Affiliation(s)
- Asa E Conover
- Department of Marine and Environmental Biology, University of Southern California, CA, USA
| | - Michael Morando
- Department of Marine and Environmental Biology, University of Southern California, CA, USA
| | - Yiming Zhao
- Department of Marine and Environmental Biology, University of Southern California, CA, USA
| | - Jacob Semones
- Department of Marine and Environmental Biology, University of Southern California, CA, USA
| | - David A Hutchins
- Department of Marine and Environmental Biology, University of Southern California, CA, USA
| | - Eric A Webb
- Department of Marine and Environmental Biology, University of Southern California, CA, USA
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29
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Quorum-Sensing Signals from Epibiont Mediate the Induction of Novel Microviridins in the Mat-Forming Cyanobacterial Genus Nostoc. mSphere 2021; 6:e0056221. [PMID: 34259556 PMCID: PMC8386392 DOI: 10.1128/msphere.00562-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
The regulation of the production of oligopeptides is essential in understanding their ecological role in complex microbial communities, including harmful cyanobacterial blooms. The role of chemical communication between the cyanobacterium and the microbial community harbored as epibionts within its phycosphere is at an initial stage of research, and little is understood about its specificity. Here, we present insight into the role of a bacterial epibiont in regulating the production of novel microviridins isolated from Nostoc, an ecologically important cyanobacterial genus. Microviridins are well-known elastase inhibitors with presumed antigrazing effects. Heterologous expression and identification of specific signal molecules from the epibiont suggest the role of a quorum-sensing-based interaction. Furthermore, physiological experiments show an increase in microviridin production without affecting cyanobacterial growth and photosynthetic activity. Simultaneously, oligopeptides presenting a selective inhibition pattern provide support for their specific function in response to the presence of cohabitant epibionts. Thus, the chemical interaction revealed in our study provides an example of an interspecies signaling pathway monitoring the bacterial flora around the cyanobacterial filaments and the induction of intrinsic species-specific metabolic responses. IMPORTANCE The regulation of the production of cyanopeptides beyond microcystin is essential to understand their ecological role in complex microbial communities, e.g., harmful cyanobacterial blooms. The role of chemical communication between the cyanobacterium and the epibionts within its phycosphere is at an initial stage of research, and little is understood about its specificity. The frequency of cyanopeptide occurrence also demonstrates the need to understand the contribution of cyanobacterial peptides to the overall biological impact of cyanopeptides on aquatic organisms and vertebrates, including humans. Our results shed light on the epibiont control of microviridin production via quorum-sensing mechanisms, and we posit that such mechanisms may be widespread in natural cyanobacterial bloom community regulation.
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30
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Dow L. How Do Quorum-Sensing Signals Mediate Algae-Bacteria Interactions? Microorganisms 2021; 9:microorganisms9071391. [PMID: 34199114 PMCID: PMC8307130 DOI: 10.3390/microorganisms9071391] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 06/11/2021] [Accepted: 06/15/2021] [Indexed: 11/16/2022] Open
Abstract
Quorum sensing (QS) describes a process by which bacteria can sense the local cell density of their own species, thus enabling them to coordinate gene expression and physiological processes on a community-wide scale. Small molecules called autoinducers or QS signals, which act as intraspecies signals, mediate quorum sensing. As our knowledge of QS has progressed, so too has our understanding of the structural diversity of QS signals, along with the diversity of bacteria conducting QS and the range of ecosystems in which QS takes place. It is now also clear that QS signals are more than just intraspecies signals. QS signals mediate interactions between species of prokaryotes, and between prokaryotes and eukaryotes. In recent years, our understanding of QS signals as mediators of algae-bacteria interactions has advanced such that we are beginning to develop a mechanistic understanding of their effects. This review will summarize the recent efforts to understand how different classes of QS signals contribute to the interactions between planktonic microalgae and bacteria in our oceans, primarily N-acyl-homoserine lactones, their degradation products of tetramic acids, and 2-alkyl-4-quinolones. In particular, this review will discuss the ways in which QS signals alter microalgae growth and metabolism, namely as direct effectors of photosynthesis, regulators of the cell cycle, and as modulators of other algicidal mechanisms. Furthermore, the contribution of QS signals to nutrient acquisition is discussed, and finally, how microalgae can modulate these small molecules to dampen their effects.
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Affiliation(s)
- Lachlan Dow
- Root Microbe Interactions Laboratory, Australian National University, Canberra 0200, Australia
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Hermann L, Mais CN, Czech L, Smits SHJ, Bange G, Bremer E. The ups and downs of ectoine: structural enzymology of a major microbial stress protectant and versatile nutrient. Biol Chem 2021; 401:1443-1468. [PMID: 32755967 DOI: 10.1515/hsz-2020-0223] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 07/22/2020] [Indexed: 12/13/2022]
Abstract
Ectoine and its derivative 5-hydroxyectoine are compatible solutes and chemical chaperones widely synthesized by Bacteria and some Archaea as cytoprotectants during osmotic stress and high- or low-growth temperature extremes. The function-preserving attributes of ectoines led to numerous biotechnological and biomedical applications and fostered the development of an industrial scale production process. Synthesis of ectoines requires the expenditure of considerable energetic and biosynthetic resources. Hence, microorganisms have developed ways to exploit ectoines as nutrients when they are no longer needed as stress protectants. Here, we summarize our current knowledge on the phylogenomic distribution of ectoine producing and consuming microorganisms. We emphasize the structural enzymology of the pathways underlying ectoine biosynthesis and consumption, an understanding that has been achieved only recently. The synthesis and degradation pathways critically differ in the isomeric form of the key metabolite N-acetyldiaminobutyric acid (ADABA). γ-ADABA serves as preferred substrate for the ectoine synthase, while the α-ADABA isomer is produced by the ectoine hydrolase as an intermediate in catabolism. It can serve as internal inducer for the genetic control of ectoine catabolic genes via the GabR/MocR-type regulator EnuR. Our review highlights the importance of structural enzymology to inspire the mechanistic understanding of metabolic networks at the biological scale.
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Affiliation(s)
- Lucas Hermann
- Department of Biology, Laboratory for Microbiology, Philipps-University Marburg, Karl-von Frisch Str. 8, D-35043 Marburg, Germany.,Biochemistry and Synthetic Biology of Microbial Metabolism Group, Max Planck Institute for Terrestrial Microbiology, Karl-von Frisch Str. 10, D-35043 Marburg, Germany
| | - Christopher-Nils Mais
- Center for Synthetic Microbiology (SYNMIKRO) & Faculty of Chemistry, Philipps-University Marburg, Hans-Meerwein Str. 6, D-35043 Marburg, Germany
| | - Laura Czech
- Department of Biology, Laboratory for Microbiology, Philipps-University Marburg, Karl-von Frisch Str. 8, D-35043 Marburg, Germany.,Center for Synthetic Microbiology (SYNMIKRO) & Faculty of Chemistry, Philipps-University Marburg, Hans-Meerwein Str. 6, D-35043 Marburg, Germany
| | - Sander H J Smits
- Center for Structural Studies, Heinrich Heine University Düsseldorf, Universitätsstr. 1, D-40225 Düsseldorf, Germany.,Institute of Biochemistry, Heinrich Heine University Düsseldorf, Universitätsstr. 1, D-40225 Düsseldorf, Germany
| | - Gert Bange
- Center for Synthetic Microbiology (SYNMIKRO) & Faculty of Chemistry, Philipps-University Marburg, Hans-Meerwein Str. 6, D-35043 Marburg, Germany
| | - Erhard Bremer
- Department of Biology, Laboratory for Microbiology, Philipps-University Marburg, Karl-von Frisch Str. 8, D-35043 Marburg, Germany.,Center for Synthetic Microbiology (SYNMIKRO), Philipps University Marburg, Hans-Meerwein Str. 6, D-35043 Marburg, Germany
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Wilson JM, Chamberlain EJ, Erazo N, Carter ML, Bowman JS. Recurrent microbial community types driven by nearshore and seasonal processes in coastal Southern California. Environ Microbiol 2021; 23:3225-3239. [PMID: 33928761 DOI: 10.1111/1462-2920.15548] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 04/26/2021] [Indexed: 01/04/2023]
Abstract
A multitude of concurrent biological and physical processes contribute to microbial community turnover, especially in highly dynamic coastal environments. Characterizing what factors contribute most to shifts in microbial community structure and the specific organisms that correlate with changes in the products of photosynthesis improves our understanding of nearshore microbial ecosystem functions. We conducted high frequency sampling in nearshore Southern California in order to capture sub-weekly microbial community dynamics. Microbial communities were characterized by flow cytometry and 16S rRNA gene sequencing, and placed in the context of physicochemical parameters. Within our time-series, season and nutrient availability corresponded to changes in dominant microbial community members. Concurrent aseasonal drivers with overlapping scales of variability were also apparent when we used network analysis to assess the microbial community as subsets of the whole. Our analyses revealed the microbial community as a mosaic, with overlapping groups of taxa that varied on different timescales and correlated with unique abiotic and biotic factors. Specifically, a subnetwork associated with chlorophyll a exhibited rapid turnover, indicating that ecologically important subsets of the microbial community can change on timescales different than and in response to factors other than those that govern turnover of most members of the assemblage.
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Affiliation(s)
- Jesse M Wilson
- Scripps Institution of Oceanography, UCSD, La Jolla, CA, USA
| | | | - Natalia Erazo
- Scripps Institution of Oceanography, UCSD, La Jolla, CA, USA
| | | | - Jeff S Bowman
- Scripps Institution of Oceanography, UCSD, La Jolla, CA, USA.,Center for Microbiome Innovation, UCSD, La Jolla, CA, USA.,Center for Marine Biodiversity and Conservation, UCSD, La Jolla, CA, USA
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Smith DJ, Tan JY, Powers MA, Lin XN, Davis TW, Dick GJ. Individual Microcystis colonies harbour distinct bacterial communities that differ by Microcystis oligotype and with time. Environ Microbiol 2021; 23:3020-3036. [PMID: 33830633 DOI: 10.1111/1462-2920.15514] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 03/11/2021] [Accepted: 04/06/2021] [Indexed: 12/31/2022]
Abstract
Interactions between bacteria and phytoplankton in the phycosphere have impacts at the scale of whole ecosystems, including the development of harmful algal blooms. The cyanobacterium Microcystis causes toxic blooms that threaten freshwater ecosystems and human health globally. Microcystis grows in colonies that harbour dense assemblages of other bacteria, yet the taxonomic composition of these phycosphere communities and the nature of their interactions with Microcystis are not well characterized. To identify the taxa and compositional variance within Microcystis phycosphere communities, we performed 16S rRNA V4 region amplicon sequencing on individual Microcystis colonies collected biweekly via high-throughput droplet encapsulation during a western Lake Erie cyanobacterial bloom. The Microcystis phycosphere communities were distinct from microbial communities in whole water and bulk phytoplankton seston in western Lake Erie but lacked 'core' taxa found across all colonies. However, dissimilarity in phycosphere community composition correlated with sampling date and the Microcystis 16S rRNA oligotype. Several taxa in the phycosphere were specific to and conserved with Microcystis of a single oligotype or sampling date. Together, this suggests that physiological differences between Microcystis strains, temporal changes in strain phenotypes, and the composition of seeding communities may impact community composition of the Microcystis phycosphere.
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Affiliation(s)
- Derek J Smith
- Department of Earth & Environmental Science, The University of Michigan, 1100 N. University Building, 1100 N. University Avenue, Ann Arbor, MI, 48109, USA
| | - James Y Tan
- Department of Chemical Engineering, The University of Michigan, NCRC, 2800 Plymouth Rd., Ann Abor, MI, 48109, USA
| | - McKenzie A Powers
- Department of Earth & Environmental Science, The University of Michigan, 1100 N. University Building, 1100 N. University Avenue, Ann Arbor, MI, 48109, USA
| | - Xiaoxia N Lin
- Department of Chemical Engineering, The University of Michigan, NCRC, 2800 Plymouth Rd., Ann Abor, MI, 48109, USA
| | - Timothy W Davis
- Department of Biological Sciences, Bowling Green State University, Life Sciences Building, Corner of N. College Dr and E. Merry Avenue, Bowling Green, OH, 43403, USA
| | - Gregory J Dick
- Department of Earth & Environmental Science, The University of Michigan, 1100 N. University Building, 1100 N. University Avenue, Ann Arbor, MI, 48109, USA
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Niche dimensions of a marine bacterium are identified using invasion studies in coastal seawater. Nat Microbiol 2021; 6:524-532. [PMID: 33495621 DOI: 10.1038/s41564-020-00851-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 12/11/2020] [Indexed: 01/29/2023]
Abstract
Niche theory is a foundational ecological concept that explains the distribution of species in natural environments. Identifying the dimensions of any organism's niche is challenging because numerous environmental factors can affect organism viability. We used serial invasion experiments to introduce Ruegeria pomeroyi DSS-3, a heterotrophic marine bacterium, into a coastal phytoplankton bloom on 14 dates. RNA-sequencing analysis of R. pomeroyi was conducted after 90 min to assess its niche dimensions in this dynamic ecosystem. We identified ~100 external conditions eliciting transcriptional responses, which included substrates, nutrients, metals and biotic interactions such as antagonism, resistance and cofactor synthesis. The peak bloom was characterized by favourable states for most of the substrate dimensions, but low inferred growth rates of R. pomeroyi at this stage indicated that its niche was narrowed by factors other than substrate availability, most probably negative biotic interactions with the bloom dinoflagellate. Our findings indicate chemical and biological features of the ocean environment that can constrain where heterotrophic bacteria survive.
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Han Y, Jiao N, Zhang Y, Zhang F, He C, Liang X, Cai R, Shi Q, Tang K. Opportunistic bacteria with reduced genomes are effective competitors for organic nitrogen compounds in coastal dinoflagellate blooms. MICROBIOME 2021; 9:71. [PMID: 33762013 PMCID: PMC7992965 DOI: 10.1186/s40168-021-01022-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 02/02/2021] [Indexed: 05/29/2023]
Abstract
BACKGROUND Phytoplankton blooms are frequent events in coastal areas and increase the production of organic matter that initially shapes the growth of opportunistic heterotrophic bacteria. However, it is unclear how these opportunists are involved in the transformation of dissolved organic matter (DOM) when blooms occur and the subsequent impacts on biogeochemical cycles. RESULTS We used a combination of genomic, proteomic, and metabolomic approaches to study bacterial diversity, genome traits, and metabolic responses to assess the source and lability of DOM in a spring coastal bloom of Akashiwo sanguinea. We identified molecules that significantly increased during bloom development, predominantly belonging to amino acids, dipeptides, lipids, nucleotides, and nucleosides. The opportunistic members of the bacterial genera Polaribacter, Lentibacter, and Litoricola represented a significant proportion of the free-living and particle-associated bacterial assemblages during the stationary phase of the bloom. Polaribacter marinivivus, Lentibacter algarum, and Litoricola marina were isolated and their genomes exhibited streamlining characterized by small genome size and low GC content and non-coding densities, as well as a smaller number of transporters and peptidases compared to closely related species. However, the core proteomes identified house-keeping functions, such as various substrate transporters, peptidases, motility, chemotaxis, and antioxidants, in response to bloom-derived DOM. We observed a unique metabolic signature for the three species in the utilization of multiple dissolved organic nitrogen compounds. The metabolomic data showed that amino acids and dipeptides (such as isoleucine and proline) were preferentially taken up by P. marinivivus and L. algarum, whereas nucleotides and nucleosides (such as adenosine and purine) were preferentially selected by L. marina. CONCLUSIONS The results suggest that the enriched DOM in stationary phase of phytoplankton bloom is a result of ammonium depletion. This environment drives genomic streamlining of opportunistic bacteria to exploit their preferred nitrogen-containing compounds and maintain nutrient cycling. Video abstract.
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Affiliation(s)
- Yu Han
- State Key Laboratory of Marine Environmental Science, Fujian Key Laboratory of Marine Carbon Sequestration, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, People's Republic of China
| | - Nianzhi Jiao
- State Key Laboratory of Marine Environmental Science, Fujian Key Laboratory of Marine Carbon Sequestration, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, People's Republic of China
| | - Yao Zhang
- State Key Laboratory of Marine Environmental Science, Fujian Key Laboratory of Marine Carbon Sequestration, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, People's Republic of China
| | - Fan Zhang
- Department of Molecular Virology & Microbiology, Center for Metagenomics and Microbiome Research, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Chen He
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum (Beijing), Beijing, 102249, People's Republic of China
| | - Xuejiao Liang
- State Key Laboratory of Marine Environmental Science, Fujian Key Laboratory of Marine Carbon Sequestration, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, People's Republic of China
| | - Ruanhong Cai
- State Key Laboratory of Marine Environmental Science, Fujian Key Laboratory of Marine Carbon Sequestration, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, People's Republic of China
| | - Quan Shi
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum (Beijing), Beijing, 102249, People's Republic of China
| | - Kai Tang
- State Key Laboratory of Marine Environmental Science, Fujian Key Laboratory of Marine Carbon Sequestration, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, People's Republic of China.
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Sörenson E, Capo E, Farnelid H, Lindehoff E, Legrand C. Temperature Stress Induces Shift From Co-Existence to Competition for Organic Carbon in Microalgae-Bacterial Photobioreactor Community - Enabling Continuous Production of Microalgal Biomass. Front Microbiol 2021; 12:607601. [PMID: 33643237 PMCID: PMC7905023 DOI: 10.3389/fmicb.2021.607601] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 01/12/2021] [Indexed: 12/17/2022] Open
Abstract
To better predict the consequences of environmental change on aquatic microbial ecosystems it is important to understand what enables community resilience. The mechanisms by which a microbial community maintain its overall function, for example, the cycling of carbon, when exposed to a stressor, can be explored by considering three concepts: biotic interactions, functional adaptations, and community structure. Interactions between species are traditionally considered as, e.g., mutualistic, parasitic, or neutral but are here broadly defined as either coexistence or competition, while functions relate to their metabolism (e.g., autotrophy or heterotrophy) and roles in ecosystem functioning (e.g., oxygen production, organic matter degradation). The term structure here align with species richness and diversity, where a more diverse community is though to exhibit a broader functional capacity than a less diverse community. These concepts have here been combined with ecological theories commonly used in resilience studies, i.e., adaptive cycles, panarchy, and cross-scale resilience, that describe how the status and behavior at one trophic level impact that of surrounding levels. This allows us to explore the resilience of a marine microbial community, cultivated in an outdoor photobioreactor, when exposed to a naturally occurring seasonal stress. The culture was monitored for 6weeks during which it was exposed to two different temperature regimes (21 ± 2 and 11 ± 1°C). Samples were taken for metatranscriptomic analysis, in order to assess the regulation of carbon uptake and utilization, and for amplicon (18S and 16S rRNA gene) sequencing, to characterize the community structure of both autotrophs (dominated by the green microalgae Mychonastes) and heterotrophs (associated bacterioplankton). Differential gene expression analyses suggested that community function at warm temperatures was based on concomitant utilization of inorganic and organic carbon assigned to autotrophs and heterotrophs, while at colder temperatures, the uptake of organic carbon was performed primarily by autotrophs. Upon the shift from high to low temperature, community interactions shifted from coexistence to competition for organic carbon. Network analysis indicated that the community structure showed opposite trends for autotrophs and heterotrophs in having either high or low diversity. Despite an abrupt change of temperature, the microbial community as a whole responded in a way that maintained the overall level of diversity and function within and across autotrophic and heterotrophic levels. This is in line with cross-scale resilience theory describing how ecosystems may balance functional overlaps within and functional redundancy between levels in order to be resilient to environmental change (such as temperature).
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Affiliation(s)
- Eva Sörenson
- Department of Biology and Environmental Science, Centre of Ecology and Evolution and Microbial Model Systems, Linnaeus University, Kalmar, Sweden
| | - Eric Capo
- Department of Chemistry, Umeå University, Umeå, Sweden
| | - Hanna Farnelid
- Department of Biology and Environmental Science, Centre of Ecology and Evolution and Microbial Model Systems, Linnaeus University, Kalmar, Sweden
| | - Elin Lindehoff
- Department of Biology and Environmental Science, Centre of Ecology and Evolution and Microbial Model Systems, Linnaeus University, Kalmar, Sweden
| | - Catherine Legrand
- Department of Biology and Environmental Science, Centre of Ecology and Evolution and Microbial Model Systems, Linnaeus University, Kalmar, Sweden
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Bowerman KL, Rehman SF, Vaughan A, Lachner N, Budden KF, Kim RY, Wood DLA, Gellatly SL, Shukla SD, Wood LG, Yang IA, Wark PA, Hugenholtz P, Hansbro PM. Disease-associated gut microbiome and metabolome changes in patients with chronic obstructive pulmonary disease. Nat Commun 2020; 11:5886. [PMID: 33208745 PMCID: PMC7676259 DOI: 10.1038/s41467-020-19701-0] [Citation(s) in RCA: 178] [Impact Index Per Article: 44.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Accepted: 10/19/2020] [Indexed: 02/07/2023] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is the third commonest cause of death globally, and manifests as a progressive inflammatory lung disease with no curative treatment. The lung microbiome contributes to COPD progression, but the function of the gut microbiome remains unclear. Here we examine the faecal microbiome and metabolome of COPD patients and healthy controls, finding 146 bacterial species differing between the two groups. Several species, including Streptococcus sp000187445, Streptococcus vestibularis and multiple members of the family Lachnospiraceae, also correlate with reduced lung function. Untargeted metabolomics identifies a COPD signature comprising 46% lipid, 20% xenobiotic and 20% amino acid related metabolites. Furthermore, we describe a disease-associated network connecting Streptococcus parasanguinis_B with COPD-associated metabolites, including N-acetylglutamate and its analogue N-carbamoylglutamate. While correlative, our results suggest that the faecal microbiome and metabolome of COPD patients are distinct from those of healthy individuals, and may thus aid in the search for biomarkers for COPD. Chronic obstructive pulmonary disease (COPD) is a progressing disease, with lung but not gut microbiota implicated in its etiology. Here the authors compare the stool from patients with COPD and healthy controls to find specific gut bacteria and metabolites associated with active disease, thereby hinting at a potential role for the gut microbiome in COPD.
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Affiliation(s)
- Kate L Bowerman
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Saima Firdous Rehman
- Priority Research Centre for Healthy Lungs, Hunter Medical Research Institute, and The University of Newcastle, Newcastle, NSW, Australia
| | - Annalicia Vaughan
- Thoracic Research Centre, Faculty of Medicine, The University of Queensland, and Department of Thoracic Medicine, The Prince Charles Hospital, Brisbane, QLD, Australia
| | - Nancy Lachner
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Kurtis F Budden
- Priority Research Centre for Healthy Lungs, Hunter Medical Research Institute, and The University of Newcastle, Newcastle, NSW, Australia
| | - Richard Y Kim
- Centre for Inflammation, Centenary Institute & University of Technology Sydney, School of Life Sciences, Faculty of Science, Sydney, NSW, Australia
| | - David L A Wood
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Shaan L Gellatly
- Priority Research Centre for Healthy Lungs, Hunter Medical Research Institute, and The University of Newcastle, Newcastle, NSW, Australia
| | - Shakti D Shukla
- Priority Research Centre for Healthy Lungs, Hunter Medical Research Institute, and The University of Newcastle, Newcastle, NSW, Australia
| | - Lisa G Wood
- Priority Research Centre for Healthy Lungs, Hunter Medical Research Institute, and The University of Newcastle, Newcastle, NSW, Australia
| | - Ian A Yang
- Thoracic Research Centre, Faculty of Medicine, The University of Queensland, and Department of Thoracic Medicine, The Prince Charles Hospital, Brisbane, QLD, Australia
| | - Peter A Wark
- Priority Research Centre for Healthy Lungs, Hunter Medical Research Institute, and The University of Newcastle, Newcastle, NSW, Australia
| | - Philip Hugenholtz
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Philip M Hansbro
- Priority Research Centre for Healthy Lungs, Hunter Medical Research Institute, and The University of Newcastle, Newcastle, NSW, Australia. .,Centre for Inflammation, Centenary Institute & University of Technology Sydney, School of Life Sciences, Faculty of Science, Sydney, NSW, Australia.
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Shibl AA, Isaac A, Ochsenkühn MA, Cárdenas A, Fei C, Behringer G, Arnoux M, Drou N, Santos MP, Gunsalus KC, Voolstra CR, Amin SA. Diatom modulation of select bacteria through use of two unique secondary metabolites. Proc Natl Acad Sci U S A 2020; 117:27445-27455. [PMID: 33067398 PMCID: PMC7959551 DOI: 10.1073/pnas.2012088117] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Unicellular eukaryotic phytoplankton, such as diatoms, rely on microbial communities for survival despite lacking specialized compartments to house microbiomes (e.g., animal gut). Microbial communities have been widely shown to benefit from diatom excretions that accumulate within the microenvironment surrounding phytoplankton cells, known as the phycosphere. However, mechanisms that enable diatoms and other unicellular eukaryotes to nurture specific microbiomes by fostering beneficial bacteria and repelling harmful ones are mostly unknown. We hypothesized that diatom exudates may tune microbial communities and employed an integrated multiomics approach using the ubiquitous diatom Asterionellopsis glacialis to reveal how it modulates its naturally associated bacteria. We show that A. glacialis reprograms its transcriptional and metabolic profiles in response to bacteria to secrete a suite of central metabolites and two unusual secondary metabolites, rosmarinic acid and azelaic acid. While central metabolites are utilized by potential bacterial symbionts and opportunists alike, rosmarinic acid promotes attachment of beneficial bacteria to the diatom and simultaneously suppresses the attachment of opportunists. Similarly, azelaic acid enhances growth of beneficial bacteria while simultaneously inhibiting growth of opportunistic ones. We further show that the bacterial response to azelaic acid is numerically rare but globally distributed in the world's oceans and taxonomically restricted to a handful of bacterial genera. Our results demonstrate the innate ability of an important unicellular eukaryotic group to modulate select bacteria in their microbial consortia, similar to higher eukaryotes, using unique secondary metabolites that regulate bacterial growth and behavior inversely across different bacterial populations.
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Affiliation(s)
- Ahmed A Shibl
- Marine Microbial Ecology Laboratory, Biology Program, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
| | - Ashley Isaac
- Marine Microbial Ecology Laboratory, Biology Program, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
- International Max Planck Research School of Marine Microbiology, University of Bremen, Bremen 28334, Germany
| | - Michael A Ochsenkühn
- Marine Microbial Ecology Laboratory, Biology Program, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
| | - Anny Cárdenas
- Department of Biology, University of Konstanz, Konstanz 78467, Germany
- Red Sea Research Center, Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Cong Fei
- Marine Microbial Ecology Laboratory, Biology Program, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
| | - Gregory Behringer
- Marine Microbial Ecology Laboratory, Biology Program, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
| | - Marc Arnoux
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
| | - Nizar Drou
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
| | - Miraflor P Santos
- Marine Microbial Ecology Laboratory, Biology Program, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
| | - Kristin C Gunsalus
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY 10003
| | - Christian R Voolstra
- Department of Biology, University of Konstanz, Konstanz 78467, Germany
- Red Sea Research Center, Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Shady A Amin
- Marine Microbial Ecology Laboratory, Biology Program, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates;
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40
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Ferrer-González FX, Widner B, Holderman NR, Glushka J, Edison AS, Kujawinski EB, Moran MA. Resource partitioning of phytoplankton metabolites that support bacterial heterotrophy. ISME JOURNAL 2020; 15:762-773. [PMID: 33097854 PMCID: PMC8027193 DOI: 10.1038/s41396-020-00811-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 10/02/2020] [Accepted: 10/09/2020] [Indexed: 11/09/2022]
Abstract
The communities of bacteria that assemble around marine microphytoplankton are predictably dominated by Rhodobacterales, Flavobacteriales, and families within the Gammaproteobacteria. Yet whether this consistent ecological pattern reflects the result of resource-based niche partitioning or resource competition requires better knowledge of the metabolites linking microbial autotrophs and heterotrophs in the surface ocean. We characterized molecules targeted for uptake by three heterotrophic bacteria individually co-cultured with a marine diatom using two strategies that vetted the exometabolite pool for biological relevance by means of bacterial activity assays: expression of diagnostic genes and net drawdown of exometabolites, the latter detected with mass spectrometry and nuclear magnetic resonance using novel sample preparation approaches. Of the more than 36 organic molecules with evidence of bacterial uptake, 53% contained nitrogen (including nucleosides and amino acids), 11% were organic sulfur compounds (including dihydroxypropanesulfonate and dimethysulfoniopropionate), and 28% were components of polysaccharides (including chrysolaminarin, chitin, and alginate). Overlap in phytoplankton-derived metabolite use by bacteria in the absence of competition was low, and only guanosine, proline, and N-acetyl-D-glucosamine were predicted to be used by all three. Exometabolite uptake pattern points to a key role for ecological resource partitioning in the assembly marine bacterial communities transforming recent photosynthate.
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Affiliation(s)
| | - Brittany Widner
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA
| | - Nicole R Holderman
- Department of Biochemistry and Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
| | - John Glushka
- Department of Biochemistry and Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
| | - Arthur S Edison
- Department of Biochemistry and Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
| | - Elizabeth B Kujawinski
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA
| | - Mary Ann Moran
- Department of Marine Sciences, University of Georgia, Athens, GA, 30602, USA.
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Zecher K, Hayes KR, Philipp B. Evidence of Interdomain Ammonium Cross-Feeding From Methylamine- and Glycine Betaine-Degrading Rhodobacteraceae to Diatoms as a Widespread Interaction in the Marine Phycosphere. Front Microbiol 2020; 11:533894. [PMID: 33123096 PMCID: PMC7574528 DOI: 10.3389/fmicb.2020.533894] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 09/10/2020] [Indexed: 11/13/2022] Open
Abstract
Dissolved organic nitrogen (DON) compounds such as methylamines (MAs) and glycine betaine (GBT) occur at detectable concentrations in marine habitats and are also produced and released by microalgae. For many marine bacteria, these DON compounds can serve as carbon, energy, and nitrogen sources, but microalgae usually cannot metabolize them. Interestingly though, it was previously shown that Donghicola sp. strain KarMa—a member of the marine Rhodobacteraceae—can cross-feed ammonium such that the ammonium it produces upon degrading monomethylamine (MMA) then serves as nitrogen source for the diatom Phaeodactylum tricornutum; thus, these organisms form a mutual metabolic interaction under photoautotrophic conditions. In the present study, we investigated whether this interaction plays a broader role in bacteria–diatom interactions in general. Results showed that cross-feeding between strain KarMa and P. tricornutum was also possible with di- and trimethylamine as well as with GBT. Further, cross-feeding of strain KarMa was also observed in cocultures with the diatoms Amphora coffeaeformis and Thalassiosira pseudonana with MMA as the sole nitrogen source. Regarding cross-feeding involving other Rhodobacteraceae strains, the in silico analysis of MA and GBT degradation pathways indicated that algae-associated Rhodobacteraceae-type strains likely interact with P. tricornutum in a similar manner as the strain KarMa does. For these types of strains (such as Celeribacter halophilus, Roseobacter denitrificans, Roseovarius indicus, Ruegeria pomeroyi, and Sulfitobacter noctilucicola), ammonium cross-feeding after methylamine degradation showed species-specific patterns, whereas bacterial GBT degradation always led to diatom growth. Overall, the degradation of DON compounds by the Rhodobacteraceae family and the subsequent cross-feeding of ammonium may represent a widespread, organism-specific, and regulated metabolic interaction for establishing and stabilizing associations with photoautotrophic diatoms in the oceans.
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Affiliation(s)
- Karsten Zecher
- Institute for Molecular Microbiology and Biotechnology, University of Münster, Münster, Germany
| | - Kristiane Rebecca Hayes
- Institute for Molecular Microbiology and Biotechnology, University of Münster, Münster, Germany
| | - Bodo Philipp
- Institute for Molecular Microbiology and Biotechnology, University of Münster, Münster, Germany
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Predetermined clockwork microbial worlds: Current understanding of aquatic microbial diel response from model systems to complex environments. ADVANCES IN APPLIED MICROBIOLOGY 2020; 113:163-191. [PMID: 32948266 DOI: 10.1016/bs.aambs.2020.06.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
In the photic zone of aquatic ecosystems, microorganisms with different metabolisms and their viruses form complex interactions and food webs. Within these interactions, phototrophic microorganisms such as eukaryotic microalgae and cyanobacteria interact directly with sunlight, and thereby generate circadian rhythms. Diel cycling originally generated in microbial phototrophs is directly transmitted toward heterotrophic microorganisms utilizing the photosynthetic products as they are excreted or exuded. Such diel cycling seems to be indirectly propagated toward heterotrophs as a result of complex biotic interactions. For example, cell death of phototrophic microorganisms induced by viral lysis and protistan grazing provides additional resources of dissolved organic matter to the microbial community, and so generates diel cycling in other heterotrophs with different nutrient dependencies. Likewise, differences in the diel transmitting pathway via complex interactions among heterotrophs, and between heterotrophs and their viruses, may also generate higher variation and time lag diel rhythms in different heterotrophic taxa. Thus, sunlight and photosynthesis not only contribute energy and carbon supply, but also directly or indirectly control diel cycling of the microbial community through complex interactions in the photic zone of aquatic ecosystems.
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Liu Y, Lin Q, Feng J, Yang F, Du H, Hu Z, Wang H. Differences in metabolic potential between particle-associated and free-living bacteria along Pearl River Estuary. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 728:138856. [PMID: 32570327 DOI: 10.1016/j.scitotenv.2020.138856] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 04/15/2020] [Accepted: 04/19/2020] [Indexed: 06/11/2023]
Abstract
Particulate organic matter (POM) in aquatic ecosystem is critical for biogeochemical cycling and host distinct communities of microbes, compared to its surrounding water. In this study, the structures and functional potentials of microbial communities associated with particles or free-living in water samples from the Pearl River Estuary were investigated using 16S rRNA gene sequencing and GeoChip 5.0 analysis. Significant differences in the community structure and genetic functional potentials between particle-associated bacteria and free-living bacteria were observed across all eight sampling sites. In particle-associated bacteria communities, Rhodobacteraceae and Flavobacteriaceae were more abundant, while SAR11 clade and SAR86 clade were the most abundant in free-living bacteria communities. The richness and abundance of functional genes involved in nutrient cycling and stress response, including carbon degradation, nitrogen fixation, DMSP degradation, and polyphosphate degradation, were much higher in particle-associated bacteria compared with free-living bacteria. Thus, the particle-associated bacteria seem to play a much more important role in the biogeochemical cycles than free-living bacteria. In conclusion, the results from this study highlight the central role played by particle-associated bacteria in structuring microbial assemblages, and their importance for mediating biogeochemical cycling in the estuarine ecosystem.
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Affiliation(s)
- Yanyang Liu
- Biology Department, College of Science, Shantou University, Shantou 515063, China; Institute of Marine Sciences, Shantou University, Shantou 515063, China; Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China
| | - Qun Lin
- Biology Department, College of Science, Shantou University, Shantou 515063, China; Institute of Marine Sciences, Shantou University, Shantou 515063, China; Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China
| | - Jiarong Feng
- Biology Department, College of Science, Shantou University, Shantou 515063, China; Institute of Marine Sciences, Shantou University, Shantou 515063, China; Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China
| | - Fumin Yang
- Biology Department, College of Science, Shantou University, Shantou 515063, China; Institute of Marine Sciences, Shantou University, Shantou 515063, China; Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China
| | - Hong Du
- Biology Department, College of Science, Shantou University, Shantou 515063, China; Institute of Marine Sciences, Shantou University, Shantou 515063, China; Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China
| | - Zhong Hu
- Biology Department, College of Science, Shantou University, Shantou 515063, China; Institute of Marine Sciences, Shantou University, Shantou 515063, China; Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China
| | - Hui Wang
- Biology Department, College of Science, Shantou University, Shantou 515063, China; Institute of Marine Sciences, Shantou University, Shantou 515063, China; Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China.
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Genome Sequences and Metagenome-Assembled Genome Sequences of Microbial Communities Enriched on Phytoplankton Exometabolites. Microbiol Resour Announc 2020; 9:9/30/e00724-20. [PMID: 32703840 PMCID: PMC7378039 DOI: 10.1128/mra.00724-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
We report 11 bacterial draft genome sequences and 38 metagenome-assembled genomes (MAGs) from marine phytoplankton exometabolite enrichments. The genomes and MAGs represent marine bacteria adapted to the metabolite environment of phycospheres, organic matter-rich regions surrounding phytoplankton cells, and are useful for exploring functional and taxonomic attributes of phytoplankton-associated bacterial communities. We report 11 bacterial draft genome sequences and 38 metagenome-assembled genomes (MAGs) from marine phytoplankton exometabolite enrichments. The genomes and MAGs represent marine bacteria adapted to the metabolite environment of phycospheres, organic matter-rich regions surrounding phytoplankton cells, and are useful for exploring functional and taxonomic attributes of phytoplankton-associated bacterial communities.
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Mais CN, Hermann L, Altegoer F, Seubert A, Richter AA, Wernersbach I, Czech L, Bremer E, Bange G. Degradation of the microbial stress protectants and chemical chaperones ectoine and hydroxyectoine by a bacterial hydrolase-deacetylase complex. J Biol Chem 2020; 295:9087-9104. [PMID: 32404365 PMCID: PMC7335791 DOI: 10.1074/jbc.ra120.012722] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Revised: 05/06/2020] [Indexed: 12/12/2022] Open
Abstract
When faced with increased osmolarity in the environment, many bacterial cells accumulate the compatible solute ectoine and its derivative 5-hydroxyectoine. Both compounds are not only potent osmostress protectants, but also serve as effective chemical chaperones stabilizing protein functionality. Ectoines are energy-rich nitrogen and carbon sources that have an ecological impact that shapes microbial communities. Although the biochemistry of ectoine and 5-hydroxyectoine biosynthesis is well understood, our understanding of their catabolism is only rudimentary. Here, we combined biochemical and structural approaches to unravel the core of ectoine and 5-hydroxy-ectoine catabolisms. We show that a conserved enzyme bimodule consisting of the EutD ectoine/5-hydroxyectoine hydrolase and the EutE deacetylase degrades both ectoines. We determined the high-resolution crystal structures of both enzymes, derived from the salt-tolerant bacteria Ruegeria pomeroyi and Halomonas elongata These structures, either in their apo-forms or in forms capturing substrates or intermediates, provided detailed insights into the catalytic cores of the EutD and EutE enzymes. The combined biochemical and structural results indicate that the EutD homodimer opens the pyrimidine ring of ectoine through an unusual covalent intermediate, N-α-2 acetyl-l-2,4-diaminobutyrate (α-ADABA). We found that α-ADABA is then deacetylated by the zinc-dependent EutE monomer into diaminobutyric acid (DABA), which is further catabolized to l-aspartate. We observed that the EutD-EutE bimodule synthesizes exclusively the α-, but not the γ-isomers of ADABA or hydroxy-ADABA. Of note, α-ADABA is known to induce the MocR/GabR-type repressor EnuR, which controls the expression of many ectoine catabolic genes clusters. We conclude that hydroxy-α-ADABA might serve a similar function.
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Affiliation(s)
- Christopher-Nils Mais
- Philipps-University Marburg, Center for Synthetic Microbiology (SYNMIKRO) & Faculty of Chemistry, Marburg, Germany
| | - Lucas Hermann
- Philipps-University Marburg, Center for Synthetic Microbiology (SYNMIKRO) & Faculty of Biology, Marburg, Germany
| | - Florian Altegoer
- Philipps-University Marburg, Center for Synthetic Microbiology (SYNMIKRO) & Faculty of Chemistry, Marburg, Germany
| | - Andreas Seubert
- Philipps-University Marburg, Faculty of Chemistry, Marburg, Germany
| | - Alexandra A Richter
- Philipps-University Marburg, Center for Synthetic Microbiology (SYNMIKRO) & Faculty of Biology, Marburg, Germany
| | - Isa Wernersbach
- Philipps-University Marburg, Center for Synthetic Microbiology (SYNMIKRO) & Faculty of Chemistry, Marburg, Germany
| | - Laura Czech
- Philipps-University Marburg, Center for Synthetic Microbiology (SYNMIKRO) & Faculty of Biology, Marburg, Germany
| | - Erhard Bremer
- Philipps-University Marburg, Center for Synthetic Microbiology (SYNMIKRO) & Faculty of Biology, Marburg, Germany.
| | - Gert Bange
- Philipps-University Marburg, Center for Synthetic Microbiology (SYNMIKRO) & Faculty of Chemistry, Marburg, Germany.
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Zhong ZP, Rapp JZ, Wainaina JM, Solonenko NE, Maughan H, Carpenter SD, Cooper ZS, Jang HB, Bolduc B, Deming JW, Sullivan MB. Viral Ecogenomics of Arctic Cryopeg Brine and Sea Ice. mSystems 2020; 5:e00246-20. [PMID: 32546670 PMCID: PMC7300359 DOI: 10.1128/msystems.00246-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 05/24/2020] [Indexed: 01/09/2023] Open
Abstract
Arctic regions, which are changing rapidly as they warm 2 to 3 times faster than the global average, still retain microbial habitats that serve as natural laboratories for understanding mechanisms of microbial adaptation to extreme conditions. Seawater-derived brines within both sea ice (sea-ice brine) and ancient layers of permafrost (cryopeg brine) support diverse microbes adapted to subzero temperatures and high salinities, yet little is known about viruses in these extreme environments, which, if analogous to other systems, could play important evolutionary and ecosystem roles. Here, we characterized viral communities and their functions in samples of cryopeg brine, sea-ice brine, and melted sea ice. Viral abundance was high in cryopeg brine (1.2 × 108 ml-1) and much lower in sea-ice brine (1.3 × 105 to 2.1 × 105 ml-1), which roughly paralleled the differences in cell concentrations in these samples. Five low-input, quantitative viral metagenomes were sequenced to yield 476 viral populations (i.e., species level; ≥10 kb), only 12% of which could be assigned taxonomy by traditional database approaches, indicating a high degree of novelty. Additional analyses revealed that these viruses: (i) formed communities that differed between sample type and vertically with sea-ice depth; (ii) infected hosts that dominated these extreme ecosystems, including Marinobacter, Glaciecola, and Colwellia; and (iii) encoded fatty acid desaturase (FAD) genes that likely helped their hosts overcome cold and salt stress during infection, as well as mediated horizontal gene transfer of FAD genes between microbes. Together, these findings contribute to understanding viral abundances and communities and how viruses impact their microbial hosts in subzero brines and sea ice.IMPORTANCE This study explores viral community structure and function in remote and extreme Arctic environments, including subzero brines within marine layers of permafrost and sea ice, using a modern viral ecogenomics toolkit for the first time. In addition to providing foundational data sets for these climate-threatened habitats, we found evidence that the viruses had habitat specificity, infected dominant microbial hosts, encoded host-derived metabolic genes, and mediated horizontal gene transfer among hosts. These results advance our understanding of the virosphere and how viruses influence extreme ecosystems. More broadly, the evidence that virally mediated gene transfers may be limited by host range in these extreme habitats contributes to a mechanistic understanding of genetic exchange among microbes under stressful conditions in other systems.
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Affiliation(s)
- Zhi-Ping Zhong
- Byrd Polar and Climate Research Center, The Ohio State University, Columbus, Ohio, USA
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
| | - Josephine Z Rapp
- School of Oceanography, University of Washington, Seattle, Washington, USA
| | - James M Wainaina
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
| | | | | | - Shelly D Carpenter
- School of Oceanography, University of Washington, Seattle, Washington, USA
| | - Zachary S Cooper
- School of Oceanography, University of Washington, Seattle, Washington, USA
| | - Ho Bin Jang
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
| | - Benjamin Bolduc
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
| | - Jody W Deming
- School of Oceanography, University of Washington, Seattle, Washington, USA
| | - Matthew B Sullivan
- Byrd Polar and Climate Research Center, The Ohio State University, Columbus, Ohio, USA
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
- Department of Civil, Environmental and Geodetic Engineering, The Ohio State University, Columbus, Ohio, USA
- Center of Microbiome Science, The Ohio State University, Columbus, Ohio, USA
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Band-Schmidt CJ, Zumaya-Higuera MG, López-Cortés DJ, Leyva-Valencia I, Quijano-Scheggia SI, Hernández-Guerrero CJ. Allelopathic effects of Margalefidinium polykrikoides and Gymnodinium impudicum in the growth of Gymnodinium catenatum. HARMFUL ALGAE 2020; 96:101846. [PMID: 32560831 DOI: 10.1016/j.hal.2020.101846] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 05/23/2020] [Accepted: 05/24/2020] [Indexed: 06/11/2023]
Abstract
Harmful algae blooms (HABs) are characterized for the coexistence of phytoplankton species with dynamic and complex biotic interactions (e.g., competition, symbiosis, predation, parasitism, allelopathy), that occur at fine temporal and spatial scales, and are relevant to understand the role that different species of phytoplankton play in the regulation of HABs. In this work the allelopathic effects of Margalefidinium polykrikoides (=Cochlodinium polykrikoides) and Gymnodinium impudicum on Gymnodinium catenatum were evaluated. The allelopathic abilities of M. polykrikoides and G. impudicum were investigated in bi-algal culture experiments and in trials in which target species were co-cultured, separated by a 10 μm membrane to prevent a direct cell-to-cell contact; and also by the addition of different volumes of culture media without cells. For all trials, cells of each species were harvested during exponential phase and cultured together by triplicate at three relative abundances: 1:1 (200 Cells mL-1 of each species, G. catenatum and M. polykrikoides or G. impudicum), 2:1 (400 Cells mL-1 of G. catenatum and 200 Cells mL-1 of M. polykrikoides or G. impudicum), and 1:2 (200 cells mL-1 of G. catenatum and 400 Cells mL-1 of M. polykrikoides or G. impudicum). All bioassays were carried out by triplicate in 250 mL Erlenmeyer flasks with 150 mL of modified GSe medium with an initial inoculum of 200 or 400 Cells mL-1. During experiments G. catenatum abundances were enumerated daily. In bi-algal culture experiments mortalities of G. catenatum were from 50% to 100% after 48 h of cell contact with M. polykrikoides or G. impudicum. In the case of culture media without cells, only M. polykrikoides caused a decrease in the cell abundance and growth rate of G. catenatum. Morphological changes occurred in G. catenatum when in contact with M. polykrikoides and G. impudicum, such as membrane shedding, prominent nucleus, loss of flagella, cell lysis, as well as the separation of long chains into individual cells. These results suggest that in the natural environment M. polykrikoides and G. impudicum have allelopathic interactions in G. catenatum, which could negatively affect its growth and survival, indicating that these species could displace blooms of G. catenatum.
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Affiliation(s)
- Christine J Band-Schmidt
- Instituto Politécnico Nacional. Centro Interdisciplinario de Ciencias Marinas (IPN-CICIMAR), Apartado Postal 592, La Paz, B.C.S. 23000, Mexico.
| | - Miriam G Zumaya-Higuera
- Instituto Politécnico Nacional. Centro Interdisciplinario de Ciencias Marinas (IPN-CICIMAR), Apartado Postal 592, La Paz, B.C.S. 23000, Mexico
| | - David J López-Cortés
- Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Calle IPN #195, La Paz, B.C.S. 23096, Mexico
| | - Ignacio Leyva-Valencia
- CONACyT-Instituto Politécnico Nacional, Centro Interdisciplinario de Ciencias Marinas, Apartado Postal 592, CP 23000, La Paz, Baja California Sur, Mexico
| | - Sonia I Quijano-Scheggia
- Universidad de Colima, Centro Universitario de Investigaciones Oceanológicas, Km 20 Carretera Manzanillo-Barra de Navidad, Colonia El Naranjo, CP 28860. Manzanillo, Colima, Mexico
| | - Claudia J Hernández-Guerrero
- Instituto Politécnico Nacional. Centro Interdisciplinario de Ciencias Marinas (IPN-CICIMAR), Apartado Postal 592, La Paz, B.C.S. 23000, Mexico
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Single-cell bacterial transcription measurements reveal the importance of dimethylsulfoniopropionate (DMSP) hotspots in ocean sulfur cycling. Nat Commun 2020; 11:1942. [PMID: 32327645 PMCID: PMC7181598 DOI: 10.1038/s41467-020-15693-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 03/20/2020] [Indexed: 01/09/2023] Open
Abstract
Dimethylsulfoniopropionate (DMSP) is a pivotal compound in marine biogeochemical cycles and a key chemical currency in microbial interactions. Marine bacteria transform DMSP via two competing pathways with considerably different biogeochemical implications: demethylation channels sulfur into the microbial food web, whereas cleavage releases sulfur into the atmosphere. Here, we present single-cell measurements of the expression of these two pathways using engineered fluorescent reporter strains of Ruegeria pomeroyi DSS-3, and find that external DMSP concentration dictates the relative expression of the two pathways. DMSP induces an upregulation of both pathways, but only at high concentrations (>1 μM for demethylation; >35 nM for cleavage), characteristic of microscale hotspots such as the vicinity of phytoplankton cells. Co-incubations between DMSP-producing microalgae and bacteria revealed an increase in cleavage pathway expression close to the microalgae’s surface. These results indicate that bacterial utilization of microscale DMSP hotspots is an important determinant of the fate of sulfur in the ocean. DMSP is a ubiquitous organosulfur compound in the ocean that, once degraded by bacteria, plays key roles in global biogeochemical cycles and climate regulation. Here, the authors use single-cell measurements of transcription to investigate the intricate dynamics of bacterial DMSP degradation.
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49
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Fu H, Uchimiya M, Gore J, Moran MA. Ecological drivers of bacterial community assembly in synthetic phycospheres. Proc Natl Acad Sci U S A 2020; 117:3656-3662. [PMID: 32015111 PMCID: PMC7035482 DOI: 10.1073/pnas.1917265117] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
In the nutrient-rich region surrounding marine phytoplankton cells, heterotrophic bacterioplankton transform a major fraction of recently fixed carbon through the uptake and catabolism of phytoplankton metabolites. We sought to understand the rules by which marine bacterial communities assemble in these nutrient-enhanced phycospheres, specifically addressing the role of host resources in driving community coalescence. Synthetic systems with varying combinations of known exometabolites of marine phytoplankton were inoculated with seawater bacterial assemblages, and communities were transferred daily to mimic the average duration of natural phycospheres. We found that bacterial community assembly was predictable from linear combinations of the taxa maintained on each individual metabolite in the mixture, weighted for the growth each supported. Deviations from this simple additive resource model were observed but also attributed to resource-based factors via enhanced bacterial growth when host metabolites were available concurrently. The ability of photosynthetic hosts to shape bacterial associates through excreted metabolites represents a mechanism by which microbiomes with beneficial effects on host growth could be recruited. In the surface ocean, resource-based assembly of host-associated communities may underpin the evolution and maintenance of microbial interactions and determine the fate of a substantial portion of Earth's primary production.
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Affiliation(s)
- He Fu
- Department of Marine Sciences, University of Georgia, Athens, GA 30602
| | - Mario Uchimiya
- Department of Marine Sciences, University of Georgia, Athens, GA 30602
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602
| | - Jeff Gore
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Mary Ann Moran
- Department of Marine Sciences, University of Georgia, Athens, GA 30602;
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50
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Fenizia S, Thume K, Wirgenings M, Pohnert G. Ectoine from Bacterial and Algal Origin Is a Compatible Solute in Microalgae. Mar Drugs 2020; 18:E42. [PMID: 31935955 PMCID: PMC7024275 DOI: 10.3390/md18010042] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Revised: 12/20/2019] [Accepted: 12/23/2019] [Indexed: 02/03/2023] Open
Abstract
Osmoregulation in phytoplankton is attributed to several highly polar low-molecular-weight metabolites. A widely accepted model considers dimethylsulfoniopropionate (DMSP) as the most important and abundant osmotically active metabolite. Using an optimized procedure for the extraction and detection of highly polar metabolites, we expand the group of phytoplankton osmolytes by identifying ectoine in several microalgae. Ectoine is known as a bacterial compatible solute, but, to the best of our knowledge, was never considered as a phytoplankton-derived product. Given the ability of microalgae to take up zwitterions, such as DMSP, we tested the hypothesis that the algal ectoine is derived from associated bacteria. We therefore analyzed methanol extracts of xenic and axenic cultures of two different species of microalgae and could detect elevated concentrations of ectoine in those that harbor associated bacteria. However, also microalgae without an associated microbiome contain ectoine in smaller amounts, pointing towards a dual origin of this metabolite in the algae from their own biosynthesis as well as from uptake. We also tested the role of ectoine in the osmoadaptation of microalgae. In the model diatoms Thalassiosira weissflogii and Phaeodactylum tricornutum, elevated amounts of ectoine were found when cultivated in seawater with salinities of 50 PSU compared to the standard culture conditions of 35 PSU. Therefore, we add ectoine to the family of osmoadaptive metabolites in phytoplankton and prove a new, potentially synergistic metabolic interplay of bacteria and algae.
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Affiliation(s)
- Simona Fenizia
- Institute for Inorganic and Analytical Chemistry, Bioorganic Analytics, Friedrich Schiller University, Lessingstrasse 8, D-07743 Jena, Germany; (S.F.); (K.T.); (M.W.)
- Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, D-07745 Jena, Germany
| | - Kathleen Thume
- Institute for Inorganic and Analytical Chemistry, Bioorganic Analytics, Friedrich Schiller University, Lessingstrasse 8, D-07743 Jena, Germany; (S.F.); (K.T.); (M.W.)
| | - Marino Wirgenings
- Institute for Inorganic and Analytical Chemistry, Bioorganic Analytics, Friedrich Schiller University, Lessingstrasse 8, D-07743 Jena, Germany; (S.F.); (K.T.); (M.W.)
| | - Georg Pohnert
- Institute for Inorganic and Analytical Chemistry, Bioorganic Analytics, Friedrich Schiller University, Lessingstrasse 8, D-07743 Jena, Germany; (S.F.); (K.T.); (M.W.)
- Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, D-07745 Jena, Germany
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