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Sudo M, Osvatic J, Taylor JD, Dufour SC, Prathep A, Wilkins LGE, Rattei T, Yuen B, Petersen JM. SoxY gene family expansion underpins adaptation to diverse hosts and environments in symbiotic sulfide oxidizers. mSystems 2024; 9:e0113523. [PMID: 38747602 DOI: 10.1128/msystems.01135-23] [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: 10/25/2023] [Accepted: 04/13/2024] [Indexed: 06/19/2024] Open
Abstract
Sulfur-oxidizing bacteria (SOB) have developed distinct ecological strategies to obtain reduced sulfur compounds for growth. These range from specialists that can only use a limited range of reduced sulfur compounds to generalists that can use many different forms as electron donors. Forming intimate symbioses with animal hosts is another highly successful ecological strategy for SOB, as animals, through their behavior and physiology, can enable access to sulfur compounds. Symbioses have evolved multiple times in a range of animal hosts and from several lineages of SOB. They have successfully colonized a wide range of habitats, from seagrass beds to hydrothermal vents, with varying availability of symbiont energy sources. Our extensive analyses of sulfur transformation pathways in 234 genomes of symbiotic and free-living SOB revealed widespread conservation in metabolic pathways for sulfur oxidation in symbionts from different host species and environments, raising the question of how they have adapted to such a wide range of distinct habitats. We discovered a gene family expansion of soxY in these genomes, with up to five distinct copies per genome. Symbionts harboring only the "canonical" soxY were typically ecological "specialists" that are associated with specific host subfamilies or environments (e.g., hydrothermal vents, mangroves). Conversely, symbionts with multiple divergent soxY genes formed versatile associations across diverse hosts in various marine environments. We hypothesize that expansion and diversification of the soxY gene family could be one genomic mechanism supporting the metabolic flexibility of symbiotic SOB enabling them and their hosts to thrive in a range of different and dynamic environments.IMPORTANCESulfur metabolism is thought to be one of the most ancient mechanisms for energy generation in microorganisms. A diverse range of microorganisms today rely on sulfur oxidation for their metabolism. They can be free-living, or they can live in symbiosis with animal hosts, where they power entire ecosystems in the absence of light, such as in the deep sea. In the millions of years since they evolved, sulfur-oxidizing bacteria have adopted several highly successful strategies; some are ecological "specialists," and some are "generalists," but which genetic features underpin these ecological strategies are not well understood. We discovered a gene family that has become expanded in those species that also seem to be "generalists," revealing that duplication, repurposing, and reshuffling existing genes can be a powerful mechanism driving ecological lifestyle shifts.
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Affiliation(s)
- Marta Sudo
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Vienna, Austria
- Doctoral School in Microbiology and Environmental Science, University of Vienna, Vienna, Austria
| | - Jay Osvatic
- Joint Microbiome Facility of the Medical University of Vienna and the University of Vienna, Vienna, Austria
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - John D Taylor
- Life Sciences, The Natural History Museum, London, United Kingdom
| | - Suzanne C Dufour
- Department of Biology, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Anchana Prathep
- Department of Biology, Faculty of Science, Prince of Songkla University, HatYai, Thailand
| | - Laetitia G E Wilkins
- Eco-Evolutionary Interactions Group, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Thomas Rattei
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Vienna, Austria
| | - Benedict Yuen
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Vienna, Austria
- Eco-Evolutionary Interactions Group, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Jillian M Petersen
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Vienna, Austria
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Goffredi SK, Panossian B, Brzechffa C, Field N, King C, Moggioli G, Rouse GW, Martín-Durán JM, Henry LM. A dynamic epibiont community associated with the bone-eating polychaete genus Osedax. mBio 2023; 14:e0314022. [PMID: 37382438 PMCID: PMC10470745 DOI: 10.1128/mbio.03140-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 05/08/2023] [Indexed: 06/30/2023] Open
Abstract
Osedax, the deep-sea annelid found at sunken whalefalls, is known to host Oceanospirillales bacterial endosymbionts intracellularly in specialized roots, which help it feed exclusively on vertebrate bones. Past studies, however, have also made mention of external bacteria on their trunks. During a 14-yr study, we reveal a dynamic, yet persistent, shift of Campylobacterales integrated into the epidermis of Osedax, which change over time as the whale carcass degrades on the sea floor. The Campylobacterales associated with seven species of Osedax, which comprise 67% of the bacterial community on the trunk, appear initially dominated by the genus Arcobacter (at early time points <24 mo), the Sulfurospirillum at intermediate stages (~50 mo), and the Sulfurimonas at later stages (>140 mo) of whale carcass decomposition. Metagenome analysis of the epibiont metabolic capabilities suggests potential for a transition from heterotrophy to autotrophy and differences in their capacity to metabolize oxygen, carbon, nitrogen, and sulfur. Compared to free-living relatives, the Osedax epibiont genomes were enriched in transposable elements, implicating genetic exchange on the host surface, and contained numerous secretions systems with eukaryotic-like protein (ELP) domains, suggesting a long evolutionary history with these enigmatic, yet widely distributed deep-sea worms. IMPORTANCE Symbiotic associations are widespread in nature and we can expect to find them in every type of ecological niche. In the last twenty years, the myriad of functions, interactions and species comprising microbe-host associations has fueled a surge of interest and appreciation for symbiosis. During this 14-year study, we reveal a dynamic population of bacterial epibionts, integrated into the epidermis of 7 species of a deep-sea worm group that feeds exclusively on the remains of marine mammals. The bacterial genomes provide clues of a long evolutionary history with these enigmatic worms. On the host surface, they exchange genes and appear to undergo ecological succession, as the whale carcass habitat degrades over time, similar to what is observed for some free-living communities. These, and other annelid worms are important keystone species for diverse deep-sea environments, yet the role of attached external bacteria in supporting host health has received relatively little attention.
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Affiliation(s)
- Shana K. Goffredi
- Department of Biology, Occidental College, Los Angeles, California, USA
| | - Balig Panossian
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, United Kingdom
| | - Camille Brzechffa
- Department of Biology, Occidental College, Los Angeles, California, USA
| | - Naomi Field
- Department of Biology, Occidental College, Los Angeles, California, USA
| | - Chad King
- Monterey Bay National Marine Sanctuary, Monterey, California, USA
| | - Giacomo Moggioli
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, United Kingdom
| | - Greg W. Rouse
- Scripps Oceanography, University of California, La Jolla, California, USA
| | - José M. Martín-Durán
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, United Kingdom
| | - Lee M. Henry
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, United Kingdom
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3
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Shu Y, Wang Y, Wei Z, Gao N, Wang S, Li C, Xing Q, Hu X, Zhang X, Zhang Y, Zhang W, Bao Z, Ding W. A bacterial symbiont in the gill of the marine scallop Argopecten irradians irradians metabolizes dimethylsulfoniopropionate. MLIFE 2023; 2:178-189. [PMID: 38817626 PMCID: PMC10989825 DOI: 10.1002/mlf2.12072] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 04/23/2023] [Accepted: 05/15/2023] [Indexed: 06/01/2024]
Abstract
Microbial lysis of dimethylsulfoniopropionate (DMSP) is a key step in marine organic sulfur cycling and has been recently demonstrated to play an important role in mediating interactions between bacteria, algae, and zooplankton. To date, microbes that have been found to lyse DMSP are largely confined to free-living and surface-attached bacteria. In this study, we report for the first time that a symbiont (termed "Rhodobiaceae bacterium HWgs001") in the gill of the marine scallop Argopecten irradians irradians can lyse and metabolize DMSP. Analysis of 16S rRNA gene sequences suggested that HWgs001 accounted for up to 93% of the gill microbiota. Microscopic observations suggested that HWgs001 lived within the gill tissue. Unlike symbionts of other bivalves, HWgs001 belongs to Alphaproteobacteria rather than Gammaproteobacteria, and no genes for carbon fixation were identified in its small genome. Moreover, HWgs001 was found to possess a dddP gene, responsible for the lysis of DMSP to acrylate. The enzymatic activity of dddP was confirmed using the heterologous expression, and in situ transcription of the gene in scallop gill tissues was demonstrated using reverse-transcription PCR. Together, these results revealed a taxonomically and functionally unique symbiont, which represents the first-documented DMSP-metabolizing symbiont likely to play significant roles in coastal marine ecosystems.
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Affiliation(s)
- Yi Shu
- MOE Key Laboratory of Marine Genetics and BreedingOcean University of ChinaQingdaoChina
- Laboratory of Tropical Marine Germplasm Resources and Breeding Engineering, Sanya Oceanographic InstitutionOcean University of ChinaSanyaChina
| | - Yongming Wang
- MOE Key Laboratory of Marine Genetics and BreedingOcean University of ChinaQingdaoChina
- Laboratory of Tropical Marine Germplasm Resources and Breeding Engineering, Sanya Oceanographic InstitutionOcean University of ChinaSanyaChina
| | - Zhongcheng Wei
- MOE Key Laboratory of Marine Genetics and BreedingOcean University of ChinaQingdaoChina
| | - Ning Gao
- MOE Key Laboratory of Marine Genetics and BreedingOcean University of ChinaQingdaoChina
- Laboratory of Tropical Marine Germplasm Resources and Breeding Engineering, Sanya Oceanographic InstitutionOcean University of ChinaSanyaChina
| | - Shuyan Wang
- College of Marine Life SciencesOcean University of ChinaQingdaoChina
| | - Chun‐Yang Li
- College of Marine Life SciencesOcean University of ChinaQingdaoChina
| | - Qiang Xing
- MOE Key Laboratory of Marine Genetics and BreedingOcean University of ChinaQingdaoChina
- College of Marine Life SciencesOcean University of ChinaQingdaoChina
| | - Xiaoli Hu
- MOE Key Laboratory of Marine Genetics and BreedingOcean University of ChinaQingdaoChina
- Laboratory of Tropical Marine Germplasm Resources and Breeding Engineering, Sanya Oceanographic InstitutionOcean University of ChinaSanyaChina
| | - Xiao‐Hua Zhang
- College of Marine Life SciencesOcean University of ChinaQingdaoChina
| | - Yu‐Zhong Zhang
- College of Marine Life SciencesOcean University of ChinaQingdaoChina
| | - Weipeng Zhang
- Institute of Evolution & Marine BiodiversityOcean University of ChinaQingdaoChina
| | - Zhenmin Bao
- MOE Key Laboratory of Marine Genetics and BreedingOcean University of ChinaQingdaoChina
- Laboratory of Tropical Marine Germplasm Resources and Breeding Engineering, Sanya Oceanographic InstitutionOcean University of ChinaSanyaChina
| | - Wei Ding
- MOE Key Laboratory of Marine Genetics and BreedingOcean University of ChinaQingdaoChina
- College of Marine Life SciencesOcean University of ChinaQingdaoChina
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Dudek NK, Galaz-Montoya JG, Shi H, Mayer M, Danita C, Celis AI, Viehboeck T, Wu GH, Behr B, Bulgheresi S, Huang KC, Chiu W, Relman DA. Previously uncharacterized rectangular bacterial structures in the dolphin mouth. Nat Commun 2023; 14:2098. [PMID: 37055390 PMCID: PMC10102025 DOI: 10.1038/s41467-023-37638-y] [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: 11/01/2021] [Accepted: 03/23/2023] [Indexed: 04/15/2023] Open
Abstract
Much remains to be explored regarding the diversity of uncultured, host-associated microbes. Here, we describe rectangular bacterial structures (RBSs) in the mouths of bottlenose dolphins. DNA staining revealed multiple paired bands within RBSs, suggesting the presence of cells dividing along the longitudinal axis. Cryogenic transmission electron microscopy and tomography showed parallel membrane-bound segments that are likely cells, encapsulated by an S-layer-like periodic surface covering. RBSs displayed unusual pilus-like appendages with bundles of threads splayed at the tips. We present multiple lines of evidence, including genomic DNA sequencing of micromanipulated RBSs, 16S rRNA gene sequencing, and fluorescence in situ hybridization, suggesting that RBSs are bacterial and distinct from the genera Simonsiella and Conchiformibius (family Neisseriaceae), with which they share similar morphology and division patterning. Our findings highlight the diversity of novel microbial forms and lifestyles that await characterization using tools complementary to genomics such as microscopy.
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Affiliation(s)
- Natasha K Dudek
- Department of Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA, 95064, USA
- Quantori, Cambridge, MA, 02142, USA
| | | | - Handuo Shi
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Megan Mayer
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, 02115, USA
| | - Cristina Danita
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
| | - Arianna I Celis
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Tobias Viehboeck
- Department of Functional and Evolutionary Ecology, Environmental Cell Biology Group, University of Vienna, Vienna, Austria
- Division of Microbial Ecology, Center for Microbiology and Environmental Systems Science, and Vienna Doctoral School of Ecology and Evolution, University of Vienna, Vienna, Austria
| | - Gong-Her Wu
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
| | - Barry Behr
- Department of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Silvia Bulgheresi
- Department of Functional and Evolutionary Ecology, Environmental Cell Biology Group, University of Vienna, Vienna, Austria
| | - Kerwyn Casey Huang
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA
- Chan Zuckerberg Biohub, San Francisco, CA, 94158, USA
| | - Wah Chiu
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - David A Relman
- Department of Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA.
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, 94158, USA.
- Infectious Diseases Section, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, 94304, USA.
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5
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Wang R, Sun R, Zhang Z, Vannini C, Di Giuseppe G, Liang A. "Candidatus Euplotechlamydia quinta," a novel chlamydia-like bacterium hosted by the ciliate Euplotes octocarinatus (Ciliophora, Spirotrichea). J Eukaryot Microbiol 2023; 70:e12945. [PMID: 36039907 DOI: 10.1111/jeu.12945] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 07/15/2022] [Accepted: 08/24/2022] [Indexed: 11/29/2022]
Abstract
Our knowledge of ciliate endosymbiont diversity greatly expanded over the past decades due to the development of characterization methods for uncultivable bacteria. Chlamydia-like bacteria have been described as symbionts of free-living amoebae and other phylogenetically diverse eukaryotic hosts. In the present work, a systematic survey of the bacterial diversity associated with the ciliate Euplotes octocarinatus strain Zam5b-1 was performed, using metagenomic screening as well as classical full-cycle rRNA approach, and a novel chlamydial symbiont was characterized. The metagenomic screening revealed 16S rRNA gene sequences from Polynucleobacter necessarius, three previously reported accessory symbionts, and a novel chlamydia-like bacterium. Following the full-cycle rRNA approach, we obtained the full-length 16S rRNA gene sequence of this chlamydia-like bacterium and developed probes for diagnostic fluorescence in situ hybridizations. The phylogenetic analysis of the 16S rRNA gene sequences unambiguously places the new bacterium in the family Rhabdochlamydiaceae. This is the first report of chlamydia-like bacterium being found in Euplotes. Based on the obtained data, the bacterium is proposed as a new candidate genus and species: "Candidatus Euplotechlamydia quinta."
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Affiliation(s)
- Ruanlin Wang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan, China
| | - Ruijuan Sun
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan, China
| | - Zhiyun Zhang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan, China
| | | | | | - Aihua Liang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan, China
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6
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Kleiner M, Kouris A, Violette M, D'Angelo G, Liu Y, Korenek A, Tolić N, Sachsenberg T, McCalder J, Lipton MS, Strous M. Ultra-sensitive isotope probing to quantify activity and substrate assimilation in microbiomes. MICROBIOME 2023; 11:24. [PMID: 36755313 PMCID: PMC9909930 DOI: 10.1186/s40168-022-01454-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 12/20/2022] [Indexed: 06/18/2023]
Abstract
BACKGROUND Stable isotope probing (SIP) approaches are a critical tool in microbiome research to determine associations between species and substrates, as well as the activity of species. The application of these approaches ranges from studying microbial communities important for global biogeochemical cycling to host-microbiota interactions in the intestinal tract. Current SIP approaches, such as DNA-SIP or nanoSIMS allow to analyze incorporation of stable isotopes with high coverage of taxa in a community and at the single cell level, respectively, however they are limited in terms of sensitivity, resolution or throughput. RESULTS Here, we present an ultra-sensitive, high-throughput protein-based stable isotope probing approach (Protein-SIP), which cuts cost for labeled substrates by 50-99% as compared to other SIP and Protein-SIP approaches and thus enables isotope labeling experiments on much larger scales and with higher replication. The approach allows for the determination of isotope incorporation into microbiome members with species level resolution using standard metaproteomics liquid chromatography-tandem mass spectrometry (LC-MS/MS) measurements. At the core of the approach are new algorithms to analyze the data, which have been implemented in an open-source software ( https://sourceforge.net/projects/calis-p/ ). We demonstrate sensitivity, precision and accuracy using bacterial cultures and mock communities with different labeling schemes. Furthermore, we benchmark our approach against two existing Protein-SIP approaches and show that in the low labeling range used our approach is the most sensitive and accurate. Finally, we measure translational activity using 18O heavy water labeling in a 63-species community derived from human fecal samples grown on media simulating two different diets. Activity could be quantified on average for 27 species per sample, with 9 species showing significantly higher activity on a high protein diet, as compared to a high fiber diet. Surprisingly, among the species with increased activity on high protein were several Bacteroides species known as fiber consumers. Apparently, protein supply is a critical consideration when assessing growth of intestinal microbes on fiber, including fiber-based prebiotics. CONCLUSIONS We demonstrate that our Protein-SIP approach allows for the ultra-sensitive (0.01 to 10% label) detection of stable isotopes of elements found in proteins, using standard metaproteomics data.
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Affiliation(s)
- Manuel Kleiner
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, USA.
| | - Angela Kouris
- Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | - Marlene Violette
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, USA
| | - Grace D'Angelo
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, USA
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Yihua Liu
- Department of Geoscience, University of Calgary, Calgary, AB, Canada
- Max Planck Institute for Biology, Tübingen, Germany
| | - Abigail Korenek
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, USA
| | - Nikola Tolić
- Environmental Molecular Science Laboratory, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Timo Sachsenberg
- Institute for Bioinformatics and Medical Informatics, University of Tübingen, Tübingen, Germany
| | - Janine McCalder
- Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | - Mary S Lipton
- Environmental Molecular Science Laboratory, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Marc Strous
- Department of Geoscience, University of Calgary, Calgary, AB, Canada.
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The microbiome of a bacterivorous marine choanoflagellate contains a resource-demanding obligate bacterial associate. Nat Microbiol 2022; 7:1466-1479. [PMID: 35970961 PMCID: PMC9418006 DOI: 10.1038/s41564-022-01174-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 06/14/2022] [Indexed: 11/08/2022]
Abstract
Microbial predators such as choanoflagellates are key players in ocean food webs. Choanoflagellates, which are the closest unicellular relatives of animals, consume bacteria and also exhibit marked biological transitions triggered by bacterial compounds, yet their native microbiomes remain uncharacterized. Here we report the discovery of a ubiquitous, uncultured bacterial lineage we name Candidatus Comchoanobacterales ord. nov., related to the human pathogen Coxiella and physically associated with the uncultured marine choanoflagellate Bicosta minor. We analyse complete ‘Comchoano’ genomes acquired after sorting single Bicosta cells, finding signatures of obligate host-dependence, including reduction of pathways encoding glycolysis, membrane components, amino acids and B-vitamins. Comchoano encode the necessary apparatus to import energy and other compounds from the host, proteins for host-cell associations and a type IV secretion system closest to Coxiella’s that is expressed in Pacific Ocean metatranscriptomes. Interactions between choanoflagellates and their microbiota could reshape the direction of energy and resource flow attributed to microbial predators, adding complexity and nuance to marine food webs. Choanoflagellates are the closest living unicellular relatives of animals and are important bacterivorous predators in the ocean. Here the authors show that the microbiome of this predator includes an obligate, host resource-dependent bacterial associate.
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Evaluation of RNA later as a Field-Compatible Preservation Method for Metaproteomic Analyses of Bacterium-Animal Symbioses. Microbiol Spectr 2021; 9:e0142921. [PMID: 34704828 PMCID: PMC8549751 DOI: 10.1128/spectrum.01429-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Field studies are central to environmental microbiology and microbial ecology, because they enable studies of natural microbial communities. Metaproteomics, the study of protein abundances in microbial communities, allows investigators to study these communities "in situ," which requires protein preservation directly in the field because protein abundance patterns can change rapidly after sampling. Ideally, a protein preservative for field deployment works rapidly and preserves the whole proteome, is stable in long-term storage, is nonhazardous and easy to transport, and is available at low cost. Although these requirements might be met by several protein preservatives, an assessment of their suitability under field conditions when targeted for metaproteomic analyses is currently lacking. Here, we compared the protein preservation performance of flash freezing and the preservation solution RNAlater using the marine gutless oligochaete Olavius algarvensis and its symbiotic microbes as a test case. In addition, we evaluated long-term RNAlater storage after 1 day, 1 week, and 4 weeks at room temperature (22°C to 23°C). We evaluated protein preservation using one-dimensional liquid chromatography-tandem mass spectrometry. We found that RNAlater and flash freezing preserved proteins equally well in terms of total numbers of identified proteins and relative abundances of individual proteins, and none of the test time points was altered, compared to time zero. Moreover, we did not find biases against specific taxonomic groups or proteins with particular biochemical properties. Based on our metaproteomic data and the logistical requirements for field deployment, we recommend RNAlater for protein preservation of field-collected samples targeted for metaproteomic analyses. IMPORTANCE Metaproteomics, the large-scale identification and quantification of proteins from microbial communities, provide direct insights into the phenotypes of microorganisms on the molecular level. To ensure the integrity of the metaproteomic data, samples need to be preserved immediately after sampling to avoid changes in protein abundance patterns. In laboratory setups, samples for proteomic analyses are most commonly preserved by flash freezing; however, liquid nitrogen or dry ice is often unavailable at remote field locations, due to their hazardous nature and transport restrictions. Our study shows that RNAlater can serve as a low-hazard, easy-to-transport alternative to flash freezing for field preservation of samples for metaproteomic analyses. We show that RNAlater preserves the metaproteome equally well, compared to flash freezing, and protein abundance patterns remain stable during long-term storage for at least 4 weeks at room temperature.
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9
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Sogin EM, Kleiner M, Borowski C, Gruber-Vodicka HR, Dubilier N. Life in the Dark: Phylogenetic and Physiological Diversity of Chemosynthetic Symbioses. Annu Rev Microbiol 2021; 75:695-718. [PMID: 34351792 DOI: 10.1146/annurev-micro-051021-123130] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Possibly the last discovery of a previously unknown major ecosystem on Earth was made just over half a century ago, when researchers found teaming communities of animals flourishing two and a half kilometers below the ocean surface at hydrothermal vents. We now know that these highly productive ecosystems are based on nutritional symbioses between chemosynthetic bacteria and eukaryotes and that these chemosymbioses are ubiquitous in both deep-sea and shallow-water environments. The symbionts are primary producers that gain energy from the oxidation of reduced compounds, such as sulfide and methane, to fix carbon dioxide or methane into biomass to feed their hosts. This review outlines how the symbiotic partners have adapted to living together. We first focus on the phylogenetic and metabolic diversity of these symbioses and then highlight selected research directions that could advance our understanding of the processes that shaped the evolutionary and ecological success of these associations. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- E Maggie Sogin
- Max Planck Institute for Marine Microbiology, 28359, Bremen, Germany; ,
| | - Manuel Kleiner
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina 27607, USA
| | - Christian Borowski
- Max Planck Institute for Marine Microbiology, 28359, Bremen, Germany; , .,MARUM-Center for Marine Environmental Sciences, University of Bremen, 28359, Bremen, Germany
| | | | - Nicole Dubilier
- Max Planck Institute for Marine Microbiology, 28359, Bremen, Germany; , .,MARUM-Center for Marine Environmental Sciences, University of Bremen, 28359, Bremen, Germany
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10
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Husnik F, Tashyreva D, Boscaro V, George EE, Lukeš J, Keeling PJ. Bacterial and archaeal symbioses with protists. Curr Biol 2021; 31:R862-R877. [PMID: 34256922 DOI: 10.1016/j.cub.2021.05.049] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Most of the genetic, cellular, and biochemical diversity of life rests within single-celled organisms - the prokaryotes (bacteria and archaea) and microbial eukaryotes (protists). Very close interactions, or symbioses, between protists and prokaryotes are ubiquitous, ecologically significant, and date back at least two billion years ago to the origin of mitochondria. However, most of our knowledge about the evolution and functions of eukaryotic symbioses comes from the study of animal hosts, which represent only a small subset of eukaryotic diversity. Here, we take a broad view of bacterial and archaeal symbioses with protist hosts, focusing on their evolution, ecology, and cell biology, and also explore what functions (if any) the symbionts provide to their hosts. With the immense diversity of protist symbioses starting to come into focus, we can now begin to see how these systems will impact symbiosis theory more broadly.
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Affiliation(s)
- Filip Husnik
- Okinawa Institute of Science and Technology, Okinawa, 904-0495, Japan; Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
| | - Daria Tashyreva
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 370 05 České Budějovice, Czech Republic
| | - Vittorio Boscaro
- Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Emma E George
- Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 370 05 České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, 370 05 České Budějovice, Czech Republic
| | - Patrick J Keeling
- Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
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11
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Paredes GF, Viehboeck T, Lee R, Palatinszky M, Mausz MA, Reipert S, Schintlmeister A, Maier A, Volland JM, Hirschfeld C, Wagner M, Berry D, Markert S, Bulgheresi S, König L. Anaerobic Sulfur Oxidation Underlies Adaptation of a Chemosynthetic Symbiont to Oxic-Anoxic Interfaces. mSystems 2021; 6:e0118620. [PMID: 34058098 PMCID: PMC8269255 DOI: 10.1128/msystems.01186-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 04/20/2021] [Indexed: 11/23/2022] Open
Abstract
Chemosynthetic symbioses occur worldwide in marine habitats, but comprehensive physiological studies of chemoautotrophic bacteria thriving on animals are scarce. Stilbonematinae are coated by thiotrophic Gammaproteobacteria. As these nematodes migrate through the redox zone, their ectosymbionts experience varying oxygen concentrations. However, nothing is known about how these variations affect their physiology. Here, by applying omics, Raman microspectroscopy, and stable isotope labeling, we investigated the effect of oxygen on "Candidatus Thiosymbion oneisti." Unexpectedly, sulfur oxidation genes were upregulated in anoxic relative to oxic conditions, but carbon fixation genes and incorporation of 13C-labeled bicarbonate were not. Instead, several genes involved in carbon fixation were upregulated under oxic conditions, together with genes involved in organic carbon assimilation, polyhydroxyalkanoate (PHA) biosynthesis, nitrogen fixation, and urea utilization. Furthermore, in the presence of oxygen, stress-related genes were upregulated together with vitamin biosynthesis genes likely necessary to withstand oxidative stress, and the symbiont appeared to proliferate less. Based on its physiological response to oxygen, we propose that "Ca. T. oneisti" may exploit anaerobic sulfur oxidation coupled to denitrification to proliferate in anoxic sand. However, the ectosymbiont would still profit from the oxygen available in superficial sand, as the energy-efficient aerobic respiration would facilitate carbon and nitrogen assimilation. IMPORTANCE Chemoautotrophic endosymbionts are famous for exploiting sulfur oxidization to feed marine organisms with fixed carbon. However, the physiology of thiotrophic bacteria thriving on the surface of animals (ectosymbionts) is less understood. One longstanding hypothesis posits that attachment to animals that migrate between reduced and oxic environments would boost sulfur oxidation, as the ectosymbionts would alternatively access sulfide and oxygen, the most favorable electron acceptor. Here, we investigated the effect of oxygen on the physiology of "Candidatus Thiosymbion oneisti," a gammaproteobacterium which lives attached to marine nematodes inhabiting shallow-water sand. Surprisingly, sulfur oxidation genes were upregulated under anoxic relative to oxic conditions. Furthermore, under anoxia, the ectosymbiont appeared to be less stressed and to proliferate more. We propose that animal-mediated access to oxygen, rather than enhancing sulfur oxidation, would facilitate assimilation of carbon and nitrogen by the ectosymbiont.
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Affiliation(s)
- Gabriela F. Paredes
- University of Vienna, Department of Functional and Evolutionary Ecology, Environmental Cell Biology Group, Vienna, Austria
| | - Tobias Viehboeck
- University of Vienna, Department of Functional and Evolutionary Ecology, Environmental Cell Biology Group, Vienna, Austria
- University of Vienna, Center for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Vienna, Austria
| | - Raymond Lee
- Washington State University, School of Biological Sciences, Pullman, Washington, USA
| | - Marton Palatinszky
- University of Vienna, Center for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Vienna, Austria
| | - Michaela A. Mausz
- University of Warwick, School of Life Sciences, Coventry, United Kingdom
| | - Siegfried Reipert
- University of Vienna, Core Facility Cell Imaging and Ultrastructure Research, Vienna, Austria
| | - Arno Schintlmeister
- University of Vienna, Center for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Vienna, Austria
- University of Vienna, Center for Microbiology and Environmental Systems Science, Large-Instrument Facility for Environmental and Isotope Mass Spectrometry, Vienna, Austria
| | - Andreas Maier
- University of Vienna, Faculty of Geosciences, Geography, and Astronomy, Department of Geography and Regional Research, Geoecology, Vienna, Austria
| | - Jean-Marie Volland
- University of Vienna, Department of Functional and Evolutionary Ecology, Environmental Cell Biology Group, Vienna, Austria
| | - Claudia Hirschfeld
- University of Greifswald, Institute of Pharmacy, Department of Pharmaceutical Biotechnology, Greifswald, Germany
| | - Michael Wagner
- University of Vienna, Center for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Vienna, Austria
- Aalborg University, Department of Chemistry and Bioscience, Aalborg, Denmark
| | - David Berry
- University of Vienna, Center for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Vienna, Austria
- Joint Microbiome Facility of the Medical University of Vienna and the University of Vienna, Vienna, Austria
| | - Stephanie Markert
- University of Greifswald, Institute of Pharmacy, Department of Pharmaceutical Biotechnology, Greifswald, Germany
| | - Silvia Bulgheresi
- University of Vienna, Department of Functional and Evolutionary Ecology, Environmental Cell Biology Group, Vienna, Austria
| | - Lena König
- University of Vienna, Department of Functional and Evolutionary Ecology, Environmental Cell Biology Group, Vienna, Austria
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12
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Petersen JM, Yuen B. The symbiotic 'all-rounders': Partnerships between marine animals and chemosynthetic nitrogen-fixing bacteria. Appl Environ Microbiol 2021; 87:AEM.02129-20. [PMID: 33355107 PMCID: PMC8090883 DOI: 10.1128/aem.02129-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Nitrogen fixation is a widespread metabolic trait in certain types of microorganisms called diazotrophs. Bioavailable nitrogen is limited in various habitats on land and in the sea, and accordingly, a range of plant, animal, and single-celled eukaryotes have evolved symbioses with diverse diazotrophic bacteria, with enormous economic and ecological benefits. Until recently, all known nitrogen-fixing symbionts were heterotrophs such as nodulating rhizobia, or photoautotrophs such as cyanobacteria. In 2016, the first chemoautotrophic nitrogen-fixing symbionts were discovered in a common family of marine clams, the Lucinidae. Chemosynthetic nitrogen-fixing symbionts use the chemical energy stored in reduced sulfur compounds to power carbon and nitrogen fixation, making them metabolic 'all-rounders' with multiple functions in the symbiosis. This distinguishes them from heterotrophic symbionts that require a source of carbon from their host, and their chemosynthetic metabolism distinguishes them from photoautotrophic symbionts that produce oxygen, a potent inhibitor of nitrogenase. In this review, we consider evolutionary aspects of this discovery, by comparing strategies that have evolved for hosting intracellular nitrogen-fixing symbionts in plants and animals. The symbiosis between lucinid clams and chemosynthetic nitrogen-fixing bacteria also has important ecological impacts, as they form a nested symbiosis with endangered marine seagrasses. Notably, nitrogen fixation by lucinid symbionts may help support seagrass health by providing a source of nitrogen in seagrass habitats. These discoveries were enabled by new techniques for understanding the activity of microbial populations in natural environments. However, an animal (or plant) host represents a diverse landscape of microbial niches due to its structural, chemical, immune and behavioural properties. In future, methods that resolve microbial activity at the single cell level will provide radical new insights into the regulation of nitrogen fixation in chemosynthetic symbionts, shedding new light on the evolution of nitrogen-fixing symbioses in contrasting hosts and environments.
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Affiliation(s)
- Jillian M Petersen
- Centre for Microbiology and Environmental Systems Science, University of Vienna
| | - Benedict Yuen
- Centre for Microbiology and Environmental Systems Science, University of Vienna
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13
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Hinzke T, Kleiner M, Meister M, Schlüter R, Hentschker C, Pané-Farré J, Hildebrandt P, Felbeck H, Sievert SM, Bonn F, Völker U, Becher D, Schweder T, Markert S. Bacterial symbiont subpopulations have different roles in a deep-sea symbiosis. eLife 2021; 10:58371. [PMID: 33404502 PMCID: PMC7787665 DOI: 10.7554/elife.58371] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 12/05/2020] [Indexed: 12/13/2022] Open
Abstract
The hydrothermal vent tubeworm Riftia pachyptila hosts a single 16S rRNA phylotype of intracellular sulfur-oxidizing symbionts, which vary considerably in cell morphology and exhibit a remarkable degree of physiological diversity and redundancy, even in the same host. To elucidate whether multiple metabolic routes are employed in the same cells or rather in distinct symbiont subpopulations, we enriched symbionts according to cell size by density gradient centrifugation. Metaproteomic analysis, microscopy, and flow cytometry strongly suggest that Riftia symbiont cells of different sizes represent metabolically dissimilar stages of a physiological differentiation process: While small symbionts actively divide and may establish cellular symbiont-host interaction, large symbionts apparently do not divide, but still replicate DNA, leading to DNA endoreduplication. Moreover, in large symbionts, carbon fixation and biomass production seem to be metabolic priorities. We propose that this division of labor between smaller and larger symbionts benefits the productivity of the symbiosis as a whole.
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Affiliation(s)
- Tjorven Hinzke
- Institute of Pharmacy, University of Greifswald, Greifswald, Germany.,Institute of Marine Biotechnology, Greifswald, Germany.,Energy Bioengineering Group, University of Calgary, Calgary, Canada
| | - Manuel Kleiner
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, United States
| | - Mareike Meister
- Institute of Microbiology, University of Greifswald, Greifswald, Germany.,Leibniz Institute for Plasma Science and Technology, Greifswald, Germany
| | - Rabea Schlüter
- Imaging Center of the Department of Biology, University of Greifswald, Greifswald, Germany
| | - Christian Hentschker
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Jan Pané-Farré
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-University Marburg, Marburg, Germany
| | - Petra Hildebrandt
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Horst Felbeck
- Scripps Institution of Oceanography, University of California San Diego, San Diego, United States
| | - Stefan M Sievert
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, United States
| | - Florian Bonn
- Institute of Biochemistry, University Hospital, Goethe University School of Medicine Frankfurt, Frankfurt, Germany
| | - Uwe Völker
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Dörte Becher
- Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Thomas Schweder
- Institute of Pharmacy, University of Greifswald, Greifswald, Germany.,Institute of Marine Biotechnology, Greifswald, Germany
| | - Stephanie Markert
- Institute of Pharmacy, University of Greifswald, Greifswald, Germany.,Institute of Marine Biotechnology, Greifswald, Germany
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15
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Scharhauser F, Zimmermann J, Ott JA, Leisch N, Gruber‐Vodicka HR. Morphology of obligate ectosymbionts reveals Paralaxus gen. nov.: A new circumtropical genus of marine stilbonematine nematodes. ZOOL SCR 2020; 49:379-394. [PMID: 34857981 PMCID: PMC8614112 DOI: 10.1111/zsc.12399] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 11/05/2019] [Accepted: 11/14/2019] [Indexed: 11/30/2022]
Abstract
Stilbonematinae are a subfamily of conspicuous marine nematodes, distinguished by a coat of sulphur-oxidizing bacterial ectosymbionts on their cuticle. As most nematodes, the worm hosts have a relatively simple anatomy and few taxonomically informative characters, and this has resulted in numerous taxonomic reassignments and synonymizations. Recent studies using a combination of morphological and molecular traits have helped to improve the taxonomy of Stilbonematinae but also raised questions on the validity of several genera. Here, we describe a new circumtropically distributed genus Paralaxus (Stilbonematinae) with three species: Paralaxus cocos sp. nov., P. bermudensis sp. nov. and P. columbae sp. nov. We used single worm metagenomes to generate host 18S rRNA and cytochrome c oxidase I (COI) as well as symbiont 16S rRNA gene sequences. Intriguingly, COI alignments and primer matching analyses suggest that the COI is not suitable for PCR-based barcoding approaches in Stilbonematinae as the genera have a highly diverse base composition and no conserved primer sites. The phylogenetic analyses of all three gene sets, however, confirm the morphological assignments and support the erection of the new genus Paralaxus as well as corroborate the status of the other stilbonematine genera. Paralaxus most closely resembles the stilbonematine genus Laxus in overlapping sets of diagnostic features but can be distinguished from Laxus by the morphology of the genus-specific symbiont coat. Our re-analyses of key parameters of the symbiont coat morphology as character for all Stilbonematinae genera show that with amended descriptions, including the coat, highly reliable genus assignments can be obtained.
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Affiliation(s)
- Florian Scharhauser
- Department of Limnology and Bio‐OceanographyUniversity of ViennaViennaAustria
| | | | - Jörg A. Ott
- Department of Limnology and Bio‐OceanographyUniversity of ViennaViennaAustria
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16
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Bacterial Intracellular Sulphur Globules. BACTERIAL ORGANELLES AND ORGANELLE-LIKE INCLUSIONS 2020. [DOI: 10.1007/978-3-030-60173-7_2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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17
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Abstract
The significance of symbioses between eukaryotic hosts and microbes extends from the organismal to the ecosystem level and underpins the health of Earth’s most threatened marine ecosystems. Despite rapid growth in research on host-associated microbes, from individual microbial symbionts to host-associated consortia of significantly relevant taxa, little is known about their interactions with the vast majority of marine host species. We outline research priorities to strengthen our current knowledge of host–microbiome interactions and how they shape marine ecosystems. We argue that such advances in research will help predict responses of species, communities, and ecosystems to stressors driven by human activity and inform future management strategies. The significance of symbioses between eukaryotic hosts and microbes extends from the organismal to the ecosystem level and underpins the health of Earth’s most threatened marine ecosystems. This Perspective article outlines research priorities to strengthen our current knowledge of host-microbiome interactions, to help predict responses to anthropogenic stressors and to inform future management strategies.
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