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Liu J, Zhou Y, Feng J, Cai C, Zhang S. Comparative metagenomic analysis reveals the adaptive evolutionary traits of siboglinid tubeworm symbionts. Front Microbiol 2025; 16:1533506. [PMID: 40313410 PMCID: PMC12045306 DOI: 10.3389/fmicb.2025.1533506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2024] [Accepted: 03/28/2025] [Indexed: 05/03/2025] Open
Abstract
Tubeworms flourish in marine cold seeps and hydrothermal vents through the establishment of symbiotic relationships with chemosynthetic bacteria. However, the environmental adaptations and evolutionary relationships of tubeworm symbionts across diverse habitats and hosts remain largely unknown. In this study, we characterized the genomes of 26 siboglinid tubeworm symbionts collected from deep-sea hydrothermal vents, cold seeps, and deep-sea mud, including two sequenced in this study and 24 previously published. Phylogenetic analysis classified the 26 symbiont genomes into five distinct clusters at the genus level. The findings highlight the remarkable diversity in symbiont classification, influenced by the habitat and species of tubeworm, with the symbiont genome characteristics of various genera revealing unique evolutionary strategies. Siboglinid symbionts exhibit functional metabolic diversity, encompassing chemical autotrophic capabilities for carbon, nitrogen, and sulfur metabolism, hydrogen oxidation, and a chemoorganotrophic ability to utilize various amino acids, cofactors, and vitamins. Furthermore, the symbiont's homeostatic mechanisms and CRISPR-Cas system are vital adaptations for survival. Overall, this study highlights the metabolic traits of siboglinid symbionts across different genera and enhances our understanding of how different habitats and hosts influence symbiont evolution, offering valuable insights into the strategies that symbionts use to adapt and thrive in extreme environments.
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Affiliation(s)
- Jinyi Liu
- Research Centre of Ecology and Environment for Coastal Area and Deep Sea, Guangdong University of Technology, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
- School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou, China
- Guangdong Basic Research Center of Excellence for Ecological Security and Green Development, Guangdong University of Technology, Guangzhou, China
| | - Yingli Zhou
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
- Guangdong Basic Research Center of Excellence for Ecological Security and Green Development, Guangdong University of Technology, Guangzhou, China
| | - Jingchun Feng
- Research Centre of Ecology and Environment for Coastal Area and Deep Sea, Guangdong University of Technology, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
- School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou, China
- Guangdong Basic Research Center of Excellence for Ecological Security and Green Development, Guangdong University of Technology, Guangzhou, China
| | - Chaofeng Cai
- Research Centre of Ecology and Environment for Coastal Area and Deep Sea, Guangdong University of Technology, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
- School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou, China
- Guangdong Basic Research Center of Excellence for Ecological Security and Green Development, Guangdong University of Technology, Guangzhou, China
| | - Si Zhang
- Research Centre of Ecology and Environment for Coastal Area and Deep Sea, Guangdong University of Technology, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
- School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou, China
- Guangdong Basic Research Center of Excellence for Ecological Security and Green Development, Guangdong University of Technology, Guangzhou, China
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Wang H, Xiao H, Feng B, Lan Y, Fung CW, Zhang H, Yan G, Lian C, Zhong Z, Li J, Wang M, Wu AR, Li C, Qian PY. Single-cell RNA-seq reveals distinct metabolic "microniches" and close host-symbiont interactions in deep-sea chemosynthetic tubeworm. SCIENCE ADVANCES 2024; 10:eadn3053. [PMID: 39047091 PMCID: PMC11268408 DOI: 10.1126/sciadv.adn3053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Accepted: 06/21/2024] [Indexed: 07/27/2024]
Abstract
Vestimentiferan tubeworms that thrive in deep-sea chemosynthetic ecosystems rely on a single species of sulfide-oxidizing gammaproteobacterial endosymbionts housed in a specialized symbiotic organ called trophosome as their primary carbon source. While this simple symbiosis is remarkably productive, the host-symbiont molecular interactions remain unelucidated. Here, we applied an approach for deep-sea in situ single-cell fixation in a cold-seep tubeworm, Paraescarpia echinospica. Single-cell RNA sequencing analysis and further molecular characterizations of both the trophosome and endosymbiont indicate that the tubeworm maintains two distinct metabolic "microniches" in the trophosome by controlling the availability of chemosynthetic gases and metabolites, resulting in oxygenated and hypoxic conditions. The endosymbionts in the oxygenated niche actively conduct autotrophic carbon fixation and are digested for nutrients, while those in the hypoxic niche conduct anaerobic denitrification, which helps the host remove ammonia waste. Our study provides insights into the molecular interactions between animals and their symbiotic microbes.
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Affiliation(s)
- Hao Wang
- Institute of Oceanology, Chinese Academy of Science, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Laoshan Laboratory, Qingdao, China
| | - Hongxiu Xiao
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Buhan Feng
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Yi Lan
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Nansha, Guangzhou, China
- Department of Ocean Science, Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Cheuk Wang Fung
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Huan Zhang
- Institute of Oceanology, Chinese Academy of Science, Qingdao, China
| | - Guoyong Yan
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Nansha, Guangzhou, China
- Department of Ocean Science, Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Chao Lian
- Institute of Oceanology, Chinese Academy of Science, Qingdao, China
| | - Zhaoshan Zhong
- Institute of Oceanology, Chinese Academy of Science, Qingdao, China
| | - Jing Li
- Institute of Oceanology, Chinese Academy of Science, Qingdao, China
| | - Minxiao Wang
- Institute of Oceanology, Chinese Academy of Science, Qingdao, China
| | - Angela Ruohao Wu
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong SAR, China
- Department of Chemical and Biological Engineering, Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Chaolun Li
- Institute of Oceanology, Chinese Academy of Science, Qingdao, China
- South China Sea Institute of Oceanology, Chinese Academy of Science, Guanzhou, China
- University of Chinese Academy of Science, Beijing, China
| | - Pei-Yuan Qian
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong SAR, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Nansha, Guangzhou, China
- Department of Ocean Science, Hong Kong University of Science and Technology, Hong Kong SAR, China
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Kang W, Xiao Y, Li W, Cheng A, Cheng C, Jia Z, Yu L. Paddy cultivation in degraded karst wetland soil can significantly improve the physiological and ecological functions of carbon-fixing resident microorganisms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 909:168187. [PMID: 37972785 DOI: 10.1016/j.scitotenv.2023.168187] [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: 07/04/2023] [Revised: 10/10/2023] [Accepted: 10/27/2023] [Indexed: 11/19/2023]
Abstract
Microorganisms play an important role in carbon fixation in karst wetland soils. However, the carbon fixation capacity of karst wetland soils and active microorganisms involved in the carbon fixation process are poorly understood. In this study, carbon fixation capacity and active microorganisms involved in the fixation of inorganic carbon into organic carbon were studied in native, naturally degraded, and reclaimed karst wetland soils by the combination of stable isotope probing (SIP) and high-throughput sequencing. Under light conditions, the soil carbon fixation capacity ranked: the reclaimed wetland soil (1.58 mg C kg-1 day-1) > native wetland soil (1.43 mg C kg-1 day-1) > degraded wetland soil (0.62 mg C kg-1 day-1). In the dark, the soils ranked: the native wetland soil (0.24 mg C kg-1 day-1) > reclaimed wetland soil (0.18 mg C kg-1 day-1) > degraded wetland soil (0.06 mg C kg-1 day-1). Active microorganisms fixing inorganic carbon in the karst wetland soils were mainly Sulfurovum, Thermovirga, Dethiosulfatibacter, Allochromatium, Methylorubrum, and Bradyrhizobium. Thus, paddy cultivation can restore the carbon fixation capacity of microorganisms in the degraded karst wetland soil. This study provides an experimental basis for improving soil carbon fixation capacity and repairing degraded soil in karst wetlands.
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Affiliation(s)
- Weihua Kang
- Institute of Resource Biology and Biotechnology, Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yutian Xiao
- Institute of Resource Biology and Biotechnology, Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Wei Li
- Institute of Resource Biology and Biotechnology, Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China; Key Laboratory of Molecular Biophysics, Ministry of Education, Wuhan 430074, China.
| | - Aoqi Cheng
- Institute of Resource Biology and Biotechnology, Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Congyu Cheng
- Institute of Resource Biology and Biotechnology, Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zhongjun Jia
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Longjiang Yu
- Institute of Resource Biology and Biotechnology, Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China; Key Laboratory of Molecular Biophysics, Ministry of Education, Wuhan 430074, China
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Ratinskaia L, Malavin S, Zvi-Kedem T, Vintila S, Kleiner M, Rubin-Blum M. Metabolically-versatile Ca. Thiodiazotropha symbionts of the deep-sea lucinid clam Lucinoma kazani have the genetic potential to fix nitrogen. ISME COMMUNICATIONS 2024; 4:ycae076. [PMID: 38873029 PMCID: PMC11171427 DOI: 10.1093/ismeco/ycae076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 05/06/2024] [Accepted: 05/31/2024] [Indexed: 06/15/2024]
Abstract
Lucinid clams are one of the most diverse and widespread symbiont-bearing animal groups in both shallow and deep-sea chemosynthetic habitats. Lucinids harbor Ca. Thiodiazotropha symbionts that can oxidize inorganic and organic substrates such as hydrogen sulfide and formate to gain energy. The interplay between these key metabolic functions, nutrient uptake and biotic interactions in Ca. Thiodiazotropha is not fully understood. We collected Lucinoma kazani individuals from next to a deep-sea brine pool in the eastern Mediterranean Sea, at a depth of 1150 m and used Oxford Nanopore and Illumina sequencing to obtain high-quality genomes of their Ca. Thiodiazotropha gloverae symbiont. The genomes served as the basis for transcriptomic and proteomic analyses to characterize the in situ gene expression, metabolism and physiology of the symbionts. We found genes needed for N2 fixation in the deep-sea symbiont's genome, which, to date, were only found in shallow-water Ca. Thiodiazotropha. However, we did not detect the expression of these genes and thus the potential role of nitrogen fixation in this symbiosis remains to be determined. We also found the high expression of carbon fixation and sulfur oxidation genes, which indicate chemolithoautotrophy as the key physiology of Ca. Thiodiazotropha. However, we also detected the expression of pathways for using methanol and formate as energy sources. Our findings highlight the key traits these microbes maintain to support the nutrition of their hosts and interact with them.
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Affiliation(s)
- Lina Ratinskaia
- Biology Department, National Institute of Oceanography, Israel Oceanographic and Limnological Research (IOLR), Haifa 3108000Israel
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa 3498838Israel
| | - Stas Malavin
- Biology Department, National Institute of Oceanography, Israel Oceanographic and Limnological Research (IOLR), Haifa 3108000Israel
- Department of Environmental Hydrology and Microbiology, Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sde Boker 8499000, Israel
| | - Tal Zvi-Kedem
- Biology Department, National Institute of Oceanography, Israel Oceanographic and Limnological Research (IOLR), Haifa 3108000Israel
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa 3498838Israel
| | - Simina Vintila
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, 27695, United States
| | - Manuel Kleiner
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, 27695, United States
| | - Maxim Rubin-Blum
- Biology Department, National Institute of Oceanography, Israel Oceanographic and Limnological Research (IOLR), Haifa 3108000Israel
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa 3498838Israel
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Chen X, Liu J, Zhu XY, Xue CX, Yao P, Fu L, Yang Z, Sun K, Yu M, Wang X, Zhang XH. Phylogenetically and metabolically diverse autotrophs in the world's deepest blue hole. ISME COMMUNICATIONS 2023; 3:117. [PMID: 37964026 PMCID: PMC10645885 DOI: 10.1038/s43705-023-00327-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 10/28/2023] [Accepted: 11/02/2023] [Indexed: 11/16/2023]
Abstract
The world's deepest yongle blue hole (YBH) is characterized by sharp dissolved oxygen (DO) gradients, and considerably low-organic-carbon and high-inorganic-carbon concentrations that may support active autotrophic communities. To understand metabolic strategies of autotrophic communities for obtaining carbon and energy spanning redox gradients, we presented finer characterizations of microbial community, metagenome and metagenome-assembled genomes (MAGs) in the YBH possessing oxic, hypoxic, essentially anoxic and completely anoxic zones vertically. Firstly, the YBH microbial composition and function shifted across the four zones, linking to different biogeochemical processes. The recovery of high-quality MAGs belonging to various uncultivated lineages reflected high novelty of the YBH microbiome. Secondly, carbon fixation processes and associated energy metabolisms varied with the vertical zones. The Calvin-Benson-Bassham (CBB) cycle was ubiquitous but differed in affiliated taxa at different zones. Various carbon fixation pathways were found in the hypoxic and essentially anoxic zones, including the 3-hyroxypropionate/4-hydroxybutyrate (3HP/4HB) cycle affiliated to Nitrososphaeria, and Wood-Ljungdahl (WL) pathway affiliated to Planctomycetes, with sulfur oxidation and dissimilatory nitrate reduction as primary energy-conserving pathways. The completely anoxic zone harbored diverse taxa (Dehalococcoidales, Desulfobacterales and Desulfatiglandales) utilizing the WL pathway coupled with versatile energy-conserving pathways via sulfate reduction, fermentation, CO oxidation and hydrogen metabolism. Finally, most of the WL-pathway containing taxa displayed a mixotrophic lifestyle corresponding to flexible carbon acquisition strategies. Our result showed a vertical transition of microbial lifestyle from photo-autotrophy, chemoautotrophy to mixotrophy in the YBH, enabling a better understanding of carbon fixation processes and associated biogeochemical impacts with different oxygen availability.
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Affiliation(s)
- Xing Chen
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Jiwen Liu
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
- Laboratory for Marine Ecology and Environmental Science, Laoshan Laboratory, Qingdao, 266237, China
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, 266003, China
| | - Xiao-Yu Zhu
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Chun-Xu Xue
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Peng Yao
- Laboratory for Marine Ecology and Environmental Science, Laoshan Laboratory, Qingdao, 266237, China
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China
| | - Liang Fu
- Sansha Track Ocean Coral Reef Conservation Research Institute, Sansha, 573199, China
| | - Zuosheng Yang
- College of Marine Geosciences, Ocean University of China, Qingdao, 266100, China
| | - Kai Sun
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Min Yu
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
- Laboratory for Marine Ecology and Environmental Science, Laoshan Laboratory, Qingdao, 266237, China
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, 266003, China
| | - Xiaolei Wang
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Xiao-Hua Zhang
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China.
- Laboratory for Marine Ecology and Environmental Science, Laoshan Laboratory, Qingdao, 266237, China.
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, 266003, China.
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6
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Samanta B, Sharma S, Budhwar R. Metagenome Analysis of Speleothem Microbiome from Subterranean Cave Reveals Insight into Community Structure, Metabolic Potential, and BGCs Diversity. Curr Microbiol 2023; 80:317. [PMID: 37561193 DOI: 10.1007/s00284-023-03431-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 07/26/2023] [Indexed: 08/11/2023]
Abstract
The Borra caves, the second largest subterranean karst cave ecosystem in the Indian sub-continent, are located at the Ananthagiri hills of Araku Valley in the Alluri district of Andhra Pradesh, India. The present investigation applied a shotgun metagenomic approach to gain insights into the microbial community structure, metabolic potential, and biosynthetic gene cluster (BGC) diversity of the microbes colonizing the surface of the speleothems from the aphotic zone of Borra caves. The taxonomic analysis of the metagenome data illustrated that the speleothem-colonizing core microbial community was dominated mainly by Alpha-, Beta-, and Gamma-Proteobacteria, Actinobacteria, Firmicutes, and Bacteroidetes. The key energy metabolic pathways analysis provides strong evidence of chemolithoautotrophic and chemoheterotrophic modes of nutrition in the speleothem-colonizing microbial community. Metagenome data suggests that sulfur reducers and sulfur-disproportionating microbes might play a vital role in energy generation in this ecosystem. Our metagenome data also suggest that the dissimilatory nitrifiers and nitrifying denitrifiers might play an essential role in conserving nitrogen pools in the ecosystem. Furthermore, metagenome-wide BGCs mining retrieved 451 putative BGCs; NRPS was the most abundant (24%). Phylogenetic analysis of the C domain of NRPS showed that sequences were distributed across all six function categories of the known C domain, including several novel subclades. For example, a novel subclade had been recovered within the LCL domain clade as a sister subclade of immunosuppressant cyclosporin encoding C domain sequences. Our result suggested that subterranean cave microbiomes might be a potential reservoir of novel microbial metabolites.
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Affiliation(s)
- Brajogopal Samanta
- Department of Microbiology and FST, GITAM School of Science, GITAM (Deemed to Be University), Rushikonda, Visakhapatnam, Andhra Pradesh, 530045, India.
| | - Shivasmi Sharma
- Bionivid Technology Private Limited, Bengaluru, Karnataka, 560043, India
| | - Roli Budhwar
- Bionivid Technology Private Limited, Bengaluru, Karnataka, 560043, India
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Cheng B, Zhang D, Lin Q, Xi S, Ma J, Zan F, Biswal BK, Wang Z, Guo G. Short-chain fatty acid production and phosphorous recovery from waste activated sludge via anaerobic fermentation: A comparison of in-situ and ex-situ thiosulfate-assisted Fe 2+/persulfate pretreatment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 871:162172. [PMID: 36775172 DOI: 10.1016/j.scitotenv.2023.162172] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 02/07/2023] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
Recently, increasing attention is given on the resource and energy recovery (e.g. short-chain fatty acids (SCFAs) and phosphorus (P)) from waste active sludge (WAS) under the "Dual carbon goals". This study compared four thiosulfate-assisted Fe2+/persulfate (TAFP) pretreatments of WAS, i.e. in-situ TAFP pretreatment (R1), ex-situ TAFP pretreatment (R2), in-situ TAFP pretreatment + pH adjustment (R3) and ex-situ TAFP pretreatment + pH adjustment (R4), followed by anaerobic fermentation over 20 days for SCFA production and P recovery. The results showed that the maximal SCFA yields in R1-4 were 730.2 ± 7.0, 1017.4 ± 13.9, 860.1 ± 40.8, and 1072.0 ± 33.2 mg COD/L, respectively, significantly higher than Control (365.2 ± 17.8 mg COD/L). The findings indicated that TAFP pretreatments (particularly ex-situ TAFP pretreatment) enhanced WAS disintegration and provided more soluble organics and subsequently promoted SCFA production. The P fractionation results showed the non-apatite inorganic P increased from 11.6 ± 0.2 mg P/g TSS in Control to 11.8 ± 0.5 (R1), 12.4 ± 0.3 (R2), 13.2 ± 0.7 (R3) and 12.7 ± 0.7 mg P/g TSS (R4), suggesting TAFP pretreatments improved P bioavailability due to formation of Fe-P mineral (Fe(H2PO4)2·2H2O), which could be recycled through magnetic separators. These findings were further strengthened by the analysis of microbial community and related marker genes that fermentative bacteria containing SCFA biosynthesis genes (e.g. pyk, pdhA, accA and accB) and iron-reducing bacteria containing iron-related proteins (e.g. feoA and feoB) were enriched in R1-4 (dominant in ex-situ pretreatment systems, R2 and R4). Economic evaluation further verified ex-situ TAFP pretreatment was cost-effective and a better strategy over other operations to treat WAS for SCFA production and P recovery.
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Affiliation(s)
- Boyi Cheng
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China
| | - Da Zhang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China
| | - Qingshan Lin
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China
| | - Shihao Xi
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China
| | - Jie Ma
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China
| | - Feixiang Zan
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China
| | - Basanta Kumar Biswal
- Department of Civil & Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Zongping Wang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China
| | - Gang Guo
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China.
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8
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Rogers TJ, Buongiorno J, Jessen GL, Schrenk MO, Fordyce JA, de Moor JM, Ramírez CJ, Barry PH, Yücel M, Selci M, Cordone A, Giovannelli D, Lloyd KG. Chemolithoautotroph distributions across the subsurface of a convergent margin. THE ISME JOURNAL 2023; 17:140-150. [PMID: 36257972 PMCID: PMC9751116 DOI: 10.1038/s41396-022-01331-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 10/03/2022] [Accepted: 10/06/2022] [Indexed: 12/15/2022]
Abstract
Subducting oceanic crusts release fluids rich in biologically relevant compounds into the overriding plate, fueling subsurface chemolithoautotrophic ecosystems. To understand the impact of subsurface geochemistry on microbial communities, we collected fluid and sediments from 14 natural springs across a ~200 km transect across the Costa Rican convergent margin and performed shotgun metagenomics. The resulting 404 metagenome-assembled genomes (MAGs) cluster into geologically distinct regions based on MAG abundance patterns: outer forearc-only (25% of total relative abundance), forearc/arc-only (38% of total relative abundance), and delocalized (37% of total relative abundance) clusters. In the outer forearc, Thermodesulfovibrionia, Candidatus Bipolaricaulia, and Firmicutes have hydrogenotrophic sulfate reduction and Wood-Ljungdahl (WL) carbon fixation pathways. In the forearc/arc, Anaerolineae, Ca. Bipolaricaulia, and Thermodesulfovibrionia have sulfur oxidation, nitrogen cycling, microaerophilic respiration, and WL, while Aquificae have aerobic sulfur oxidation and reverse tricarboxylic acid carbon fixation pathway. Transformation-based canonical correspondence analysis shows that MAG distribution corresponds to concentrations of aluminum, iron, nickel, dissolved inorganic carbon, and phosphate. While delocalized MAGs appear surface-derived, the subsurface chemolithoautotrophic, metabolic, and taxonomic landscape varies by the availability of minerals/metals and volcanically derived inorganic carbon. However, the WL pathway persists across all samples, suggesting that this versatile, energy-efficient carbon fixation pathway helps shape convergent margin subsurface ecosystems.
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Affiliation(s)
| | - Joy Buongiorno
- Division of Natural Sciences, Maryville College, Maryville, TN, USA
| | - Gerdhard L Jessen
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile
- Center for Oceanographic Research COPAS COASTAL, Universidad de Concepción, Valdivia, Chile
| | | | | | - J Maarten de Moor
- National University of Costa Rica, Heredia, Costa Rica
- University of New Mexico, Albuquerque, NM, USA
| | | | - Peter H Barry
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Mustafa Yücel
- Institute of Marine Sciences, Middle East Technical University, Erdemli, Turkey
| | - Matteo Selci
- Department of Biology, University of Naples -Federico II, Naples, Italy
| | - Angela Cordone
- Department of Biology, University of Naples -Federico II, Naples, Italy
| | - Donato Giovannelli
- Department of Biology, University of Naples -Federico II, Naples, Italy
- Department of Marine and Coastal Science, Rutgers University, Rutgers, NJ, USA
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
- National Research Council - Institute of Marine Biological Resources and Biotechnologies - CNR-IRBIM, Ancona, Italy
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Zhou Z, St John E, Anantharaman K, Reysenbach AL. Global patterns of diversity and metabolism of microbial communities in deep-sea hydrothermal vent deposits. MICROBIOME 2022; 10:241. [PMID: 36572924 PMCID: PMC9793634 DOI: 10.1186/s40168-022-01424-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 11/11/2022] [Indexed: 05/16/2023]
Abstract
BACKGROUND When deep-sea hydrothermal fluids mix with cold oxygenated fluids, minerals precipitate out of solution and form hydrothermal deposits. These actively venting deep-sea hydrothermal deposits support a rich diversity of thermophilic microorganisms which are involved in a range of carbon, sulfur, nitrogen, and hydrogen metabolisms. Global patterns of thermophilic microbial diversity in deep-sea hydrothermal ecosystems have illustrated the strong connectivity between geological processes and microbial colonization, but little is known about the genomic diversity and physiological potential of these novel taxa. Here we explore this genomic diversity in 42 metagenomes from four deep-sea hydrothermal vent fields and a deep-sea volcano collected from 2004 to 2018 and document their potential implications in biogeochemical cycles. RESULTS Our dataset represents 3635 metagenome-assembled genomes encompassing 511 novel and recently identified genera from deep-sea hydrothermal settings. Some of the novel bacterial (107) and archaeal genera (30) that were recently reported from the deep-sea Brothers volcano were also detected at the deep-sea hydrothermal vent fields, while 99 bacterial and 54 archaeal genera were endemic to the deep-sea Brothers volcano deposits. We report some of the first examples of medium- (≥ 50% complete, ≤ 10% contaminated) to high-quality (> 90% complete, < 5% contaminated) MAGs from phyla and families never previously identified, or poorly sampled, from deep-sea hydrothermal environments. We greatly expand the novel diversity of Thermoproteia, Patescibacteria (Candidate Phyla Radiation, CPR), and Chloroflexota found at deep-sea hydrothermal vents and identify a small sampling of two potentially novel phyla, designated JALSQH01 and JALWCF01. Metabolic pathway analysis of metagenomes provides insights into the prevalent carbon, nitrogen, sulfur, and hydrogen metabolic processes across all sites and illustrates sulfur and nitrogen metabolic "handoffs" in community interactions. We confirm that Campylobacteria and Gammaproteobacteria occupy similar ecological guilds but their prevalence in a particular site is driven by shifts in the geochemical environment. CONCLUSION Our study of globally distributed hydrothermal vent deposits provides a significant expansion of microbial genomic diversity associated with hydrothermal vent deposits and highlights the metabolic adaptation of taxonomic guilds. Collectively, our results illustrate the importance of comparative biodiversity studies in establishing patterns of shared phylogenetic diversity and physiological ecology, while providing many targets for enrichment and cultivation of novel and endemic taxa. Video Abstract.
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Affiliation(s)
- Zhichao Zhou
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Emily St John
- Center for Life in Extreme Environments, Biology Department, Portland State University, Portland, OR, 97201, USA
| | - Karthik Anantharaman
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, 53706, USA.
| | - Anna-Louise Reysenbach
- Center for Life in Extreme Environments, Biology Department, Portland State University, Portland, OR, 97201, USA.
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De Oliveira AL, Srivastava A, Espada‐Hinojosa S, Bright M. The complete and closed genome of the facultative generalist Candidatus Endoriftia persephone from deep-sea hydrothermal vents. Mol Ecol Resour 2022; 22:3106-3123. [PMID: 35699368 PMCID: PMC9796809 DOI: 10.1111/1755-0998.13668] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 05/20/2022] [Accepted: 06/09/2022] [Indexed: 01/07/2023]
Abstract
The mutualistic interactions between Riftia pachyptila and its endosymbiont Candidatus Endoriftia persephone (short Endoriftia) have been extensively researched. However, the closed Endoriftia genome is still lacking. Here, by employing single-molecule real-time sequencing we present the closed chromosomal sequence of Endoriftia. In contrast to theoretical predictions of enlarged and mobile genetic element-rich genomes related to facultative endosymbionts, the closed Endoriftia genome is streamlined with fewer than expected coding sequence regions, insertion-, prophage-sequences and transposase-coding sequences. Automated and manually curated functional analyses indicated that Endoriftia is more versatile regarding sulphur metabolism than previously reported. We identified the presence of two identical rRNA operons and two long CRISPR regions in the closed genome. Additionally, pangenome analyses revealed the presence of three types of secretion systems (II, IV and VI) in the different Endoriftia populations indicating lineage-specific adaptations. The in depth mobilome characterization identified the presence of shared genomic islands in the different Endoriftia drafts and in the closed genome, suggesting that the acquisition of foreign DNA predates the geographical dispersal of the different endosymbiont populations. Finally, we found no evidence of epigenetic regulation in Endoriftia, as revealed by gene screenings and absence of methylated modified base motifs in the genome. As a matter of fact, the restriction-modification system seems to be dysfunctional in Endoriftia, pointing to a higher importance of molecular memory-based immunity against phages via spacer incorporation into CRISPR system. The Endoriftia genome is the first closed tubeworm endosymbiont to date and will be valuable for future gene oriented and evolutionary comparative studies.
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Affiliation(s)
| | - Abhishek Srivastava
- Department of Functional and Evolutionary EcologyUniversity of ViennaViennaAustria
| | | | - Monika Bright
- Department of Functional and Evolutionary EcologyUniversity of ViennaViennaAustria
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11
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Patra AK, Kwon YM, Yang Y. Complete gammaproteobacterial endosymbiont genome assembly from a seep tubeworm Lamellibrachia satsuma. J Microbiol 2022; 60:916-927. [DOI: 10.1007/s12275-022-2057-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 05/09/2022] [Accepted: 05/24/2022] [Indexed: 11/27/2022]
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12
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Sharma K, Park YK, Nadda AK, Banerjee P, Singh P, Raizada P, Banat F, Bharath G, Jeong SM, Lam SS. Emerging chemo-biocatalytic routes for valorization of major greenhouse gases (GHG) into industrial products: A comprehensive review. J IND ENG CHEM 2022. [DOI: 10.1016/j.jiec.2022.02.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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13
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Zvi-Kedem T, Shemesh E, Tchernov D, Rubin-Blum M. The worm affair: fidelity and environmental adaptation in symbiont species that co-occur in vestimentiferan tubeworms. ENVIRONMENTAL MICROBIOLOGY REPORTS 2021; 13:744-752. [PMID: 34374209 DOI: 10.1111/1758-2229.12994] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 06/20/2021] [Accepted: 07/19/2021] [Indexed: 06/13/2023]
Abstract
The symbioses between the vestimentiferan tubeworms and their chemosynthetic partners (Gammaproteobacteria, Chromatiales and Sedimenticolaceae) hallmark the success of these organisms in hydrothermal vent and hydrocarbon seep deep-sea habitats. The fidelity of these associations varies, as both the hosts and the symbionts can be loose in partner choice. Some tubeworms may host distinct symbiont phylotypes, which often co-occur in a single host individual. To better understand the genetic basis for the promiscuity of tubeworm symbioses, we assembled and investigated metagenome-assembled genomes of two symbiont phylotypes (species, based on the average nucleotide identity < 95%) in Lamellibrachia anaximandri, a vestimentiferan endemic to the Mediterranean Sea, in individuals collected from Palinuro hydrothermal vents (Italy) and hydrocarbon seeps (Eratosthenes seamount and Palmahim disturbance). Using comparative genomics, we show that mainly mobilome and genes involved in defence mechanisms distinguish the symbiont genotypes. While many central metabolic functions are conserved in the tubeworm symbionts, nitrate respiration (Nar, Nap and Nas proteins) is modular, yet this modularity is not linked to phylotype, but rather to geographic location, potentially implying adaptation to the local environment. Our results hint that variation in a single moonlighting protein may be responsible for the fidelity of these symbioses.
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Affiliation(s)
- Tal Zvi-Kedem
- Morris Kahn Marine Research Station, Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, 3498838, Israel
| | - Eli Shemesh
- Morris Kahn Marine Research Station, Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, 3498838, Israel
| | - Dan Tchernov
- Morris Kahn Marine Research Station, Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, 3498838, Israel
| | - Maxim Rubin-Blum
- Israel Oceanographic and Limnological Research, Haifa, 3108000, Israel
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Boeuf D, Eppley JM, Mende DR, Malmstrom RR, Woyke T, DeLong EF. Metapangenomics reveals depth-dependent shifts in metabolic potential for the ubiquitous marine bacterial SAR324 lineage. MICROBIOME 2021; 9:172. [PMID: 34389059 PMCID: PMC8364033 DOI: 10.1186/s40168-021-01119-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 06/22/2021] [Indexed: 06/01/2023]
Abstract
BACKGROUND Oceanic microbiomes play a pivotal role in the global carbon cycle and are central to the transformation and recycling of carbon and energy in the ocean's interior. SAR324 is a ubiquitous but poorly understood uncultivated clade of Deltaproteobacteria that inhabits the entire water column, from ocean surface waters to its deep interior. Although some progress has been made in elucidating potential metabolic traits of SAR324 in the dark ocean, very little is known about the ecology and the metabolic capabilities of this group in the euphotic and twilight zones. To investigate the comparative genomics, ecology, and physiological potential of the SAR324 clade, we examined the distribution and variability of key genomic features and metabolic pathways in this group from surface waters to the abyss in the North Pacific Subtropical Gyre, one of the largest biomes on Earth. RESULTS We leveraged a pangenomic ecological approach, combining spatio-temporally resolved single-amplified genome, metagenomic, and metatranscriptomic datasets. The data revealed substantial genomic diversity throughout the SAR324 clade, with distinct depth and temporal distributions that clearly differentiated ecotypes. Phylogenomic subclade delineation, environmental distributions, genomic feature similarities, and metabolic capacities revealed strong congruence. The four SAR324 ecotypes delineated in this study revealed striking divergence from one another with respect to their habitat-specific metabolic potentials. The ecotypes living in the dark or twilight oceans shared genomic features and metabolic capabilities consistent with a sulfur-based chemolithoautotrophic lifestyle. In contrast, those inhabiting the sunlit ocean displayed higher plasticity energy-related metabolic pathways, supporting a presumptive photoheterotrophic lifestyle. In epipelagic SAR324 ecotypes, we observed the presence of two types of proton-pumping rhodopsins, as well as genomic, transcriptomic, and ecological evidence for active photoheterotrophy, based on xanthorhodopsin-like light-harvesting proteins. CONCLUSIONS Combining pangenomic and both metagenomic and metatranscriptomic profiling revealed a striking divergence in the vertical distribution, genomic composition, metabolic potential, and predicted lifestyle strategies of geographically co-located members of the SAR324 bacterial clade. The results highlight the utility of metapangenomic approaches employed across environmental gradients, to decipher the properties and variation in function and ecological traits of specific phylogenetic clades within complex microbiomes. Video abstract.
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Affiliation(s)
- Dominique Boeuf
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawaii, Manoa, Honolulu, HI 96822 USA
| | - John M. Eppley
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawaii, Manoa, Honolulu, HI 96822 USA
| | - Daniel R. Mende
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawaii, Manoa, Honolulu, HI 96822 USA
| | | | - Tanja Woyke
- DOE Joint Genome Institute, Berkeley, CA 94720 USA
| | - Edward F. DeLong
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawaii, Manoa, Honolulu, HI 96822 USA
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15
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Cooccurring Activities of Two Autotrophic Pathways in Symbionts of the Hydrothermal Vent Tubeworm Riftia pachyptila. Appl Environ Microbiol 2021; 87:e0079421. [PMID: 34190607 DOI: 10.1128/aem.00794-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Genome and proteome data predict the presence of both the reductive citric acid cycle (rCAC; also called the reductive tricarboxylic acid cycle) and the Calvin-Benson-Bassham cycle (CBB) in "Candidatus Endoriftia persephonae," the autotrophic sulfur-oxidizing bacterial endosymbiont from the giant hydrothermal vent tubeworm Riftia pachyptila. We tested whether these cycles were differentially induced by sulfide supply, since the synthesis of biosynthetic intermediates by the rCAC is less energetically expensive than that by the CBB. R. pachyptila was incubated under in situ conditions in high-pressure aquaria under low (28 to 40 μmol · h-1) or high (180 to 276 μmol · h-1) rates of sulfide supply. Symbiont-bearing trophosome samples excised from R. pachyptila maintained under the two conditions were capable of similar rates of CO2 fixation. Activities of the rCAC enzyme ATP-dependent citrate lyase (ACL) and the CBB enzyme 1,3-bisphosphate carboxylase/oxygenase (RubisCO) did not differ between the two conditions, although transcript abundances for ATP-dependent citrate lyase were 4- to 5-fold higher under low-sulfide conditions. δ13C values of internal dissolved inorganic carbon (DIC) pools were varied and did not correlate with sulfide supply rate. In samples taken from freshly collected R. pachyptila, δ13C values of lipids fell between those collected for organisms using either the rCAC or the CBB exclusively. These observations are consistent with cooccurring activities of the rCAC and the CBB in this symbiosis. IMPORTANCE Previous to this study, the activities of the rCAC and CBB in R. pachyptila had largely been inferred from "omics" studies of R. pachyptila without direct assessment of in situ conditions prior to collection. In this study, R. pachyptila was maintained and monitored in high-pressure aquaria prior to measuring its CO2 fixation parameters. Results suggest that ranges in sulfide concentrations similar to those experienced in situ do not exert a strong influence on the relative activities of the rCAC and the CBB. This observation highlights the importance of further study of this symbiosis and other organisms with multiple CO2-fixing pathways, which recent genomics and biochemical studies suggest are likely to be more prevalent than anticipated.
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16
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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: 22] [Impact Index Per Article: 5.5] [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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17
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Perez M, Angers B, Young CR, Juniper SK. Shining light on a deep-sea bacterial symbiont population structure with CRISPR. Microb Genom 2021; 7:000625. [PMID: 34448690 PMCID: PMC8549365 DOI: 10.1099/mgen.0.000625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 06/07/2021] [Indexed: 01/04/2023] Open
Abstract
Many foundation species in chemosynthesis-based ecosystems rely on environmentally acquired symbiotic bacteria for their survival. Hence, understanding the biogeographic distributions of these symbionts at regional scales is key to understanding patterns of connectivity and predicting resilience of their host populations (and thus whole communities). However, such assessments are challenging because they necessitate measuring bacterial genetic diversity at fine resolutions. For this purpose, the recently discovered clustered regularly interspaced short palindromic repeats (CRISPR) constitutes a promising new genetic marker. These DNA sequences harboured by about half of bacteria hold their viral immune memory, and as such, might allow discrimination of different lineages or strains of otherwise indistinguishable bacteria. In this study, we assessed the potential of CRISPR as a hypervariable phylogenetic marker in the context of a population genetic study of an uncultured bacterial species. We used high-throughput CRISPR-based typing along with multi-locus sequence analysis (MLSA) to characterize the regional population structure of the obligate but environmentally acquired symbiont species Candidatus Endoriftia persephone on the Juan de Fuca Ridge. Mixed symbiont populations of Ca. Endoriftia persephone were sampled across individual Ridgeia piscesae hosts from contrasting habitats in order to determine if environmental conditions rather than barriers to connectivity are more important drivers of symbiont diversity. We showed that CRISPR revealed a much higher symbiont genetic diversity than the other housekeeping genes. Several lines of evidence imply this diversity is indicative of environmental strains. Finally, we found with both CRISPR and gene markers that local symbiont populations are strongly differentiated across sites known to be isolated by deep-sea circulation patterns. This research showed the high power of CRISPR to resolve the genetic structure of uncultured bacterial populations and represents a step towards making keystone microbial species an integral part of conservation policies for upcoming mining operations on the seafloor.
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18
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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: 6] [Impact Index Per Article: 1.5] [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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Schada von Borzyskowski L, Bernhardsgrütter I, Erb TJ. Biochemical unity revisited: microbial central carbon metabolism holds new discoveries, multi-tasking pathways, and redundancies with a reason. Biol Chem 2021; 401:1429-1441. [PMID: 32990641 DOI: 10.1515/hsz-2020-0214] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 09/10/2020] [Indexed: 01/27/2023]
Abstract
For a long time, our understanding of metabolism has been dominated by the idea of biochemical unity, i.e., that the central reaction sequences in metabolism are universally conserved between all forms of life. However, biochemical research in the last decades has revealed a surprising diversity in the central carbon metabolism of different microorganisms. Here, we will embrace this biochemical diversity and explain how genetic redundancy and functional degeneracy cause the diversity observed in central metabolic pathways, such as glycolysis, autotrophic CO2 fixation, and acetyl-CoA assimilation. We conclude that this diversity is not the exception, but rather the standard in microbiology.
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Affiliation(s)
- Lennart Schada von Borzyskowski
- Department of Biochemistry and Synthetic Metabolism, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Straße 10, D-35043Marburg, Germany
| | - Iria Bernhardsgrütter
- Department of Biochemistry and Synthetic Metabolism, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Straße 10, D-35043Marburg, Germany
| | - Tobias J Erb
- Department of Biochemistry and Synthetic Metabolism, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Straße 10, D-35043Marburg, Germany.,Center for Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Straße 10, D-35043Marburg, Germany
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Cambon-Bonavita MA, Aubé J, Cueff-Gauchard V, Reveillaud J. Niche partitioning in the Rimicaris exoculata holobiont: the case of the first symbiotic Zetaproteobacteria. MICROBIOME 2021; 9:87. [PMID: 33845886 PMCID: PMC8042907 DOI: 10.1186/s40168-021-01045-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 03/09/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Free-living and symbiotic chemosynthetic microbial communities support primary production and higher trophic levels in deep-sea hydrothermal vents. The shrimp Rimicaris exoculata, which dominates animal communities along the Mid-Atlantic Ridge, houses a complex bacterial community in its enlarged cephalothorax. The dominant bacteria present are from the taxonomic groups Campylobacteria, Desulfobulbia (formerly Deltaproteobacteria), Alphaproteobacteria, Gammaproteobacteria, and some recently discovered iron oxyhydroxide-coated Zetaproteobacteria. This epibiotic consortium uses iron, sulfide, methane, and hydrogen as energy sources. Here, we generated shotgun metagenomes from Rimicaris exoculata cephalothoracic epibiotic communities to reconstruct and investigate symbiotic genomes. We collected specimens from three geochemically contrasted vent fields, TAG, Rainbow, and Snake Pit, to unravel the specificity, variability, and adaptation of Rimicaris-microbe associations. RESULTS Our data enabled us to reconstruct 49 metagenome-assembled genomes (MAGs) from the TAG and Rainbow vent fields, including 16 with more than 90% completion and less than 5% contamination based on single copy core genes. These MAGs belonged to the dominant Campylobacteria, Desulfobulbia, Thiotrichaceae, and some novel candidate phyla radiation (CPR) lineages. In addition, most importantly, two MAGs in our collection were affiliated to Zetaproteobacteria and had no close relatives (average nucleotide identity ANI < 77% with the closest relative Ghiorsea bivora isolated from TAG, and 88% with each other), suggesting potential novel species. Genes for Calvin-Benson Bassham (CBB) carbon fixation, iron, and sulfur oxidation, as well as nitrate reduction, occurred in both MAGs. However, genes for hydrogen oxidation and multicopper oxidases occurred in one MAG only, suggesting shared and specific potential functions for these two novel Zetaproteobacteria symbiotic lineages. Overall, we observed highly similar symbionts co-existing in a single shrimp at both the basaltic TAG and ultramafic Rainbow vent sites. Nevertheless, further examination of the seeming functional redundancy among these epibionts revealed important differences. CONCLUSION These data highlight microniche partitioning in the Rimicaris holobiont and support recent studies showing that functional diversity enables multiple symbiont strains to coexist in animals colonizing hydrothermal vents. Video Abstract.
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Affiliation(s)
- Marie-Anne Cambon-Bonavita
- Univ Brest, CNRS, IFREMER, Laboratoire de Microbiologie des Environnements Extrêmes, 29280 Plouzané, France
| | - Johanne Aubé
- Univ Brest, CNRS, IFREMER, Laboratoire de Microbiologie des Environnements Extrêmes, 29280 Plouzané, France
| | - Valérie Cueff-Gauchard
- Univ Brest, CNRS, IFREMER, Laboratoire de Microbiologie des Environnements Extrêmes, 29280 Plouzané, France
| | - Julie Reveillaud
- Univ Brest, CNRS, IFREMER, Laboratoire de Microbiologie des Environnements Extrêmes, 29280 Plouzané, France
- MIVEGEC, Univ. Montpellier, INRAe, CNRS, IRD, Montpellier, France
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21
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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: 2.8] [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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22
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Xiao KQ, Ge TD, Wu XH, Peacock CL, Zhu ZK, Peng J, Bao P, Wu JS, Zhu YG. Metagenomic and 14 C tracing evidence for autotrophic microbial CO 2 fixation in paddy soils. Environ Microbiol 2020; 23:924-933. [PMID: 32827180 DOI: 10.1111/1462-2920.15204] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 08/17/2020] [Indexed: 12/14/2022]
Abstract
Autotrophic carbon dioxide (CO2 ) fixation by microbes is ubiquitous in the environment and potentially contributes to the soil organic carbon (SOC) pool. However, the multiple autotrophic pathways of microbial carbon assimilation and fixation in paddy soils remain poorly characterized. In this study, we combine metagenomic analysis with 14 C-labelling to investigate all known autotrophic pathways and CO2 assimilation mechanisms in five typical paddy soils from southern China. Marker genes of six autotrophic pathways are detected in all soil samples, which are dominated by the cbbL genes (67%-82%) coding the ribulose-bisphosphate carboxylase large chain in the Calvin cycle. These marker genes are associated with a broad range of phototrophic and chemotrophic genera. Significant amounts of 14 C-CO2 are assimilated into SOC (74.3-175.8 mg 14 C kg-1 ) and microbial biomass (5.2-24.1 mg 14 C kg-1 ) after 45 days incubation, where more than 70% of 14 C-SOC was concentrated in the relatively stable humin fractions. These results show that paddy soil microbes contain the genetic potential for autotrophic carbon fixation spreading over broad taxonomic ranges, and can incorporate atmospheric carbon into organic components, which ultimately contribute to the stable SOC pool.
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Affiliation(s)
- Ke-Qing Xiao
- School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK
| | - Ti-Da Ge
- Key Laboratory of Agro-ecological Processes in Subtropical Region and Changsha Research Station for Agricultural and Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, China
| | - Xiao-Hong Wu
- National Engineering Laboratory of Applied Technology for Forestry and Ecology in Southern China, Central South University of Forestry and Technology, Changsha, Hunan, 410004, China
| | - Caroline L Peacock
- School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK
| | - Zhen-Ke Zhu
- Key Laboratory of Agro-ecological Processes in Subtropical Region and Changsha Research Station for Agricultural and Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, China
| | - Jingjing Peng
- College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China
| | - Peng Bao
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Road, Xiamen, 361021, China
| | - Jin-Shui Wu
- Key Laboratory of Agro-ecological Processes in Subtropical Region and Changsha Research Station for Agricultural and Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, China
| | - Yong-Guan Zhu
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Road, Xiamen, 361021, China.,State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing, 100085, China
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23
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Breusing C, Schultz DT, Sudek S, Worden AZ, Young CR. High‐contiguity genome assembly of the chemosynthetic gammaproteobacterial endosymbiont of the cold seep tubeworm
Lamellibrachia barhami. Mol Ecol Resour 2020. [PMCID: PMC7540712 DOI: 10.1111/1755-0998.13220] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Symbiotic relationships between vestimentiferan tubeworms and chemosynthetic Gammaproteobacteria build the foundations of many hydrothermal vent and hydrocarbon seep ecosystems in the deep sea. The association between the vent tubeworm Riftia pachyptila and its endosymbiont Candidatus Endoriftia persephone has become a model system for symbiosis research in deep‐sea vestimentiferans, while markedly fewer studies have investigated symbiotic relationships in other tubeworm species, especially at cold seeps. Here we sequenced the endosymbiont genome of the tubeworm Lamellibrachia barhami from a cold seep in the Gulf of California, using short‐ and long‐read sequencing technologies in combination with Hi‐C and Dovetail Chicago libraries. Our final assembly had a size of ~4.17 MB, a GC content of 54.54%, 137X coverage, 4153 coding sequences, and a checkm completeness score of 97.19%. A single scaffold contained 99.51% of the genome. Comparative genomic analyses indicated that the L. barhami symbiont shares a set of core genes and many metabolic pathways with other vestimentiferan symbionts, while containing 433 unique gene clusters that comprised a variety of transposases, defence‐related genes and a lineage‐specific CRISPR/Cas3 system. This assembly represents the most contiguous tubeworm symbiont genome resource to date and will be particularly valuable for future comparative genomic studies investigating structural genome evolution, physiological adaptations and host‐symbiont communication in chemosynthetic animal‐microbe symbioses.
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Affiliation(s)
- Corinna Breusing
- Monterey Bay Aquarium Research Institute Moss Landing CA USA
- National Oceanography Centre Southampton UK
| | - Darrin T. Schultz
- Monterey Bay Aquarium Research Institute Moss Landing CA USA
- Department of Biomolecular Engineering and Bioinformatics University of California Santa Cruz Santa Cruz CA USA
| | - Sebastian Sudek
- Monterey Bay Aquarium Research Institute Moss Landing CA USA
| | - Alexandra Z. Worden
- Monterey Bay Aquarium Research Institute Moss Landing CA USA
- GEOMAR Helmholtz Centre for Ocean Research Kiel Germany
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24
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Miyazaki J, Ikuta T, Watsuji TO, Abe M, Yamamoto M, Nakagawa S, Takaki Y, Nakamura K, Takai K. Dual energy metabolism of the Campylobacterota endosymbiont in the chemosynthetic snail Alviniconcha marisindica. ISME JOURNAL 2020; 14:1273-1289. [PMID: 32051527 PMCID: PMC7174374 DOI: 10.1038/s41396-020-0605-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 01/16/2020] [Accepted: 01/30/2020] [Indexed: 11/09/2022]
Abstract
Some deep-sea chemosynthetic invertebrates and their symbiotic bacteria can use molecular hydrogen (H2) as their energy source. However, how much the chemosynthetic holobiont (endosymbiont-host association) physiologically depends on H2 oxidation has not yet been determined. Here, we demonstrate that the Campylobacterota endosymbionts of the gastropod Alviniconcha marisindica in the Kairei and Edmond fields (kAlv and eAlv populations, respectively) of the Indian Ocean, utilize H2 in response to their physical and environmental H2 conditions, although the 16S rRNA gene sequence of both the endosymbionts shared 99.6% identity. A thermodynamic calculation using in situ H2 and hydrogen sulfide (H2S) concentrations indicated that chemosynthetic symbiosis could be supported by metabolic energy via H2 oxidation, particularly for the kAlv holobiont. Metabolic activity measurements showed that both the living individuals and the gill tissues consumed H2 and H2S at similar levels. Moreover, a combination of fluorescence in situ hybridization, quantitative transcript analyses, and enzymatic activity measurements showed that the kAlv endosymbiont expressed the genes and enzymes for both H2- and sulfur-oxidations. These results suggest that both H2 and H2S could serve as the primary energy sources for the kAlv holobiont. The eAlv holobiont had the ability to utilize H2, but the gene expression and enzyme activity for hydrogenases were much lower than for sulfur-oxidation enzymes. These results suggest that the energy acquisitions of A. marisindica holobionts are dependent on H2- and sulfur-oxidation in the H2-enriched Kairei field and that the mechanism of dual metabolism is controlled by the in situ H2 concentration.
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Affiliation(s)
- Junichi Miyazaki
- Super-cutting-edge Grand and Advanced Research (SUGAR) Program, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka, 237-0061, Japan.
| | - Tetsuro Ikuta
- Marine Biodiversity and Environmental Assessment Research Center (BioEnv), Research Institute for Global Change (RIGC), Japan Agency for Marine-Earth Science & Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka, 237-0061, Japan
| | - Tomo-O Watsuji
- Super-cutting-edge Grand and Advanced Research (SUGAR) Program, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka, 237-0061, Japan.,Department of Food and Nutrition, Higashi-Chikushi Junior College, 5-1-1 Shimoitozu, Kitakyusyu, 803-0846, Japan
| | - Mariko Abe
- Super-cutting-edge Grand and Advanced Research (SUGAR) Program, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka, 237-0061, Japan
| | - Masahiro Yamamoto
- Super-cutting-edge Grand and Advanced Research (SUGAR) Program, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka, 237-0061, Japan
| | - Satoshi Nakagawa
- Super-cutting-edge Grand and Advanced Research (SUGAR) Program, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka, 237-0061, Japan.,Laboratory of Marine Environmental Microbiology, Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Yoshihiro Takaki
- Super-cutting-edge Grand and Advanced Research (SUGAR) Program, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka, 237-0061, Japan
| | - Kentaro Nakamura
- Department of Systems Innovation, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Ken Takai
- Super-cutting-edge Grand and Advanced Research (SUGAR) Program, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka, 237-0061, Japan
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25
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Dick GJ. The microbiomes of deep-sea hydrothermal vents: distributed globally, shaped locally. Nat Rev Microbiol 2020; 17:271-283. [PMID: 30867583 DOI: 10.1038/s41579-019-0160-2] [Citation(s) in RCA: 129] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The discovery of chemosynthetic ecosystems at deep-sea hydrothermal vents in 1977 changed our view of biology. Chemosynthetic bacteria and archaea form the foundation of vent ecosystems by exploiting the chemical disequilibrium between reducing hydrothermal fluids and oxidizing seawater, harnessing this energy to fix inorganic carbon into biomass. Recent research has uncovered fundamental aspects of these microbial communities, including their relationships with underlying geology and hydrothermal geochemistry, interactions with animals via symbiosis and distribution both locally in various habitats within vent fields and globally across hydrothermal systems in diverse settings. Although 'black smokers' and symbioses between microorganisms and macrofauna attract much attention owing to their novelty and the insights they provide into life under extreme conditions, habitats such as regions of diffuse flow, subseafloor aquifers and hydrothermal plumes have important roles in the global cycling of elements through hydrothermal systems. Owing to sharp contrasts in physical and chemical conditions between these various habitats and their dynamic, extreme and geographically isolated nature, hydrothermal vents provide a valuable window into the environmental and ecological forces that shape microbial communities and insights into the limits, origins and evolution of microbial life.
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Affiliation(s)
- Gregory J Dick
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA.
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26
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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: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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27
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Yang Y, Sun J, Sun Y, Kwan YH, Wong WC, Zhang Y, Xu T, Feng D, Zhang Y, Qiu JW, Qian PY. Genomic, transcriptomic, and proteomic insights into the symbiosis of deep-sea tubeworm holobionts. THE ISME JOURNAL 2020; 14:135-150. [PMID: 31595051 PMCID: PMC6908572 DOI: 10.1038/s41396-019-0520-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 08/11/2019] [Accepted: 08/25/2019] [Indexed: 12/22/2022]
Abstract
Deep-sea hydrothermal vents and methane seeps are often densely populated by animals that host chemosynthetic symbiotic bacteria, but the molecular mechanisms of such host-symbiont relationship remain largely unclear. We characterized the symbiont genome of the seep-living siboglinid Paraescarpia echinospica and compared seven siboglinid-symbiont genomes. Our comparative analyses indicate that seep-living siboglinid endosymbionts have more virulence traits for establishing infections and modulating host-bacterium interaction than the vent-dwelling species, and have a high potential to resist environmental hazards. Metatranscriptome and metaproteome analyses of the Paraescarpia holobiont reveal that the symbiont is highly versatile in its energy use and efficient in carbon fixation. There is close cooperation within the holobiont in production and supply of nutrients, and the symbiont may be able to obtain nutrients from host cells using virulence factors. Moreover, the symbiont is speculated to have evolved strategies to mediate host protective immunity, resulting in weak expression of host innate immunity genes in the trophosome. Overall, our results reveal the interdependence of the tubeworm holobiont through mutual nutrient supply, a pathogen-type regulatory mechanism, and host-symbiont cooperation in energy utilization and nutrient production, which is a key adaptation allowing the tubeworm to thrive in deep-sea chemosynthetic environments.
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Affiliation(s)
- Yi Yang
- Department of Ocean Science, Division of Life Science and Hong Kong Branch of The Southern Science and Engineering Guangdong Laboratory, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Jin Sun
- Department of Ocean Science, Division of Life Science and Hong Kong Branch of The Southern Science and Engineering Guangdong Laboratory, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Yanan Sun
- Department of Ocean Science, Division of Life Science and Hong Kong Branch of The Southern Science and Engineering Guangdong Laboratory, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Yick Hang Kwan
- Department of Ocean Science, Division of Life Science and Hong Kong Branch of The Southern Science and Engineering Guangdong Laboratory, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Wai Chuen Wong
- Department of Ocean Science, Division of Life Science and Hong Kong Branch of The Southern Science and Engineering Guangdong Laboratory, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Yanjie Zhang
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Ting Xu
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Dong Feng
- CAS Key Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 510301, Guangzhou, China
- Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, 266061, Qingdao, China
| | - Yu Zhang
- College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China
| | - Jian-Wen Qiu
- Department of Biology, Hong Kong Baptist University, Hong Kong, China.
| | - Pei-Yuan Qian
- Department of Ocean Science, Division of Life Science and Hong Kong Branch of The Southern Science and Engineering Guangdong Laboratory, The Hong Kong University of Science and Technology, Hong Kong, China.
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28
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Abstract
All animals are associated with microorganisms; hence, host-microbe interactions are of fundamental importance for life on earth. However, we know little about the molecular basis of these interactions. Therefore, we studied the deep-sea Riftia pachyptila symbiosis, a model association in which the tubeworm host is associated with only one phylotype of endosymbiotic bacteria and completely depends on this sulfur-oxidizing symbiont for nutrition. Using a metaproteomics approach, we identified both metabolic interaction processes, such as substrate transfer between the two partners, and interactions that serve to maintain the symbiotic balance, e.g., host efforts to control the symbiont population or symbiont strategies to modulate these host efforts. We suggest that these interactions are essential principles of mutualistic animal-microbe associations. The deep-sea tubeworm Riftia pachyptila lacks a digestive system but completely relies on bacterial endosymbionts for nutrition. Although the symbiont has been studied in detail on the molecular level, such analyses were unavailable for the animal host, because sequence information was lacking. To identify host-symbiont interaction mechanisms, we therefore sequenced the Riftia transcriptome, which served as a basis for comparative metaproteomic analyses of symbiont-containing versus symbiont-free tissues, both under energy-rich and energy-limited conditions. Our results suggest that metabolic interactions include nutrient allocation from symbiont to host by symbiont digestion and substrate transfer to the symbiont by abundant host proteins. We furthermore propose that Riftia maintains its symbiont by protecting the bacteria from oxidative damage while also exerting symbiont population control. Eukaryote-like symbiont proteins might facilitate intracellular symbiont persistence. Energy limitation apparently leads to reduced symbiont biomass and increased symbiont digestion. Our study provides unprecedented insights into host-microbe interactions that shape this highly efficient symbiosis.
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29
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Hydrogen Does Not Appear To Be a Major Electron Donor for Symbiosis with the Deep-Sea Hydrothermal Vent Tubeworm Riftia pachyptila. Appl Environ Microbiol 2019; 86:AEM.01522-19. [PMID: 31628148 DOI: 10.1128/aem.01522-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 10/09/2019] [Indexed: 12/23/2022] Open
Abstract
Use of hydrogen gas (H2) as an electron donor is common among free-living chemolithotrophic microorganisms. Given the presence of this dissolved gas at deep-sea hydrothermal vents, it has been suggested that it may also be a major electron donor for the free-living and symbiotic chemolithoautotrophic bacteria that are the primary producers at these sites. Giant Riftia pachyptila siboglinid tubeworms and their symbiotic bacteria ("Candidatus Endoriftia persephone") dominate many vents in the Eastern Pacific, and their use of sulfide as a major electron donor has been documented. Genes encoding hydrogenase are present in the "Ca Endoriftia persephone" genome, and proteome data suggest that these genes are expressed. In this study, high-pressure respirometry of intact R. pachyptila and incubations of trophosome homogenate were used to determine whether this symbiotic association could also use H2 as a major electron donor. Measured rates of H2 uptake by intact R. pachyptila in high-pressure respirometers were similar to rates measured in the absence of tubeworms. Oxygen uptake rates in the presence of H2 were always markedly lower than those measured in the presence of sulfide, as was the incorporation of 13C-labeled dissolved inorganic carbon. Carbon fixation by trophosome homogenate was not stimulated by H2, nor was hydrogenase activity detectable in these samples. Though genes encoding [NiFe] group 1e and [NiFe] group 3b hydrogenases are present in the genome and transcribed, it does not appear that H2 is a major electron donor for this system, and it may instead play a role in intracellular redox homeostasis.IMPORTANCE Despite the presence of hydrogenase genes, transcripts, and proteins in the "Ca Endoriftia persephone" genome, transcriptome, and proteome, it does not appear that R. pachyptila can use H2 as a major electron donor. For many uncultivable microorganisms, omic analyses are the basis for inferences about their activities in situ However, as is apparent from the study reported here, there are dangers in extrapolating from omics data to function, and it is essential, whenever possible, to verify functions predicted from omics data with physiological and biochemical measurements.
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30
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Li Y, Tassia MG, Waits DS, Bogantes VE, David KT, Halanych KM. Genomic adaptations to chemosymbiosis in the deep-sea seep-dwelling tubeworm Lamellibrachia luymesi. BMC Biol 2019; 17:91. [PMID: 31739792 PMCID: PMC6862839 DOI: 10.1186/s12915-019-0713-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 10/24/2019] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Symbiotic relationships between microbes and their hosts are widespread and diverse, often providing protection or nutrients, and may be either obligate or facultative. However, the genetic mechanisms allowing organisms to maintain host-symbiont associations at the molecular level are still mostly unknown, and in the case of bacterial-animal associations, most genetic studies have focused on adaptations and mechanisms of the bacterial partner. The gutless tubeworms (Siboglinidae, Annelida) are obligate hosts of chemoautotrophic endosymbionts (except for Osedax which houses heterotrophic Oceanospirillales), which rely on the sulfide-oxidizing symbionts for nutrition and growth. Whereas several siboglinid endosymbiont genomes have been characterized, genomes of hosts and their adaptations to this symbiosis remain unexplored. RESULTS Here, we present and characterize adaptations of the cold seep-dwelling tubeworm Lamellibrachia luymesi, one of the longest-lived solitary invertebrates. We sequenced the worm's ~ 688-Mb haploid genome with an overall completeness of ~ 95% and discovered that L. luymesi lacks many genes essential in amino acid biosynthesis, obligating them to products provided by symbionts. Interestingly, the host is known to carry hydrogen sulfide to thiotrophic endosymbionts using hemoglobin. We also found an expansion of hemoglobin B1 genes, many of which possess a free cysteine residue which is hypothesized to function in sulfide binding. Contrary to previous analyses, the sulfide binding mediated by zinc ions is not conserved across tubeworms. Thus, the sulfide-binding mechanisms in sibgolinids need to be further explored, and B1 globins might play a more important role than previously thought. Our comparative analyses also suggest the Toll-like receptor pathway may be essential for tolerance/sensitivity to symbionts and pathogens. Several genes related to the worm's unique life history which are known to play important roles in apoptosis, cell proliferation, and aging were also identified. Last, molecular clock analyses based on phylogenomic data suggest modern siboglinid diversity originated in 267 mya (± 70 my) support previous hypotheses indicating a Late Mesozoic or Cenozoic origins of approximately 50-126 mya for vestimentiferans. CONCLUSIONS Here, we elucidate several specific adaptations along various molecular pathways that link phenome to genome to improve understanding of holobiont evolution. Our findings of adaptation in genomic mechanisms to reducing environments likely extend to other chemosynthetic symbiotic systems.
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Affiliation(s)
- Yuanning Li
- Department of Biological Sciences & Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University, Auburn, AL, 36849, USA.
- Department of Ecology and Evolutionary Biology, Yale University, 165 Prospect St, New Haven, CT, 06511, USA.
| | - Michael G Tassia
- Department of Biological Sciences & Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University, Auburn, AL, 36849, USA
| | - Damien S Waits
- Department of Biological Sciences & Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University, Auburn, AL, 36849, USA
| | - Viktoria E Bogantes
- Department of Biological Sciences & Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University, Auburn, AL, 36849, USA
| | - Kyle T David
- Department of Biological Sciences & Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University, Auburn, AL, 36849, USA
| | - Kenneth M Halanych
- Department of Biological Sciences & Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University, Auburn, AL, 36849, USA.
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31
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Trophic structure of the macrofauna associated to deep-vents of the southern Gulf of California: Pescadero Basin and Pescadero Transform Fault. PLoS One 2019; 14:e0224698. [PMID: 31689305 PMCID: PMC6830743 DOI: 10.1371/journal.pone.0224698] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 10/18/2019] [Indexed: 11/19/2022] Open
Abstract
Newly discovered hydrothermal systems in the Pescadero Basin (PB) and the neighboring Pescadero Transform Fault (PTF) at the mouth of the Gulf of California disclosed a diverse macrofauna assemblage. The trophic structure of both ecosystems was assessed using carbon (δ13C), nitrogen (δ15N), and sulfur (δ34S) stable isotopes. The δ13C ranged from -40.8 to -12.1‰, revealing diverse carbon sources and its assimilation via Calvin-Benson-Bassham and the reductive tricarboxylic acid cycles. The δ15N values were between -12.5 and 18.3‰, corresponding to primary and secondary consumers. The δ34S values fluctuated from -36.2 to 15.1‰, indicating the sulfide assimilation of biogenic, magmatic, and photosynthetic sources. In PB high-temperature vents, primary consumers including symbiont-bearing, bacterivores and filter-feeders predominated. The secondary consumers within the scavengers/detritivores and predator guilds were scarce. The siboglinid Oasisia aff alvinae dominated the macrofauna assemblage at PB, but rather than playing a trophic role, it provides a substrate to vent dwellers. In PTF low-temperature vents, only symbiont-bearing primary consumers were analyzed, displaying the lowest δ34S values. This assemblage was dominated by the coexisting siboglinids Lamellibrachia barhami and Escarpia spicata. δ34S values allowed to distinguish between PB and PTF vent communities, to exclude the presence of methanotrophic organisms, and the detection of photosynthetic organic matter input.
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Horizontal acquisition of a patchwork Calvin cycle by symbiotic and free-living Campylobacterota (formerly Epsilonproteobacteria). ISME JOURNAL 2019; 14:104-122. [PMID: 31562384 PMCID: PMC6908604 DOI: 10.1038/s41396-019-0508-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 08/06/2019] [Accepted: 08/15/2019] [Indexed: 11/30/2022]
Abstract
Most autotrophs use the Calvin–Benson–Bassham (CBB) cycle for carbon fixation. In contrast, all currently described autotrophs from the Campylobacterota (previously Epsilonproteobacteria) use the reductive tricarboxylic acid cycle (rTCA) instead. We discovered campylobacterotal epibionts (“Candidatus Thiobarba”) of deep-sea mussels that have acquired a complete CBB cycle and may have lost most key genes of the rTCA cycle. Intriguingly, the phylogenies of campylobacterotal CBB cycle genes suggest they were acquired in multiple transfers from Gammaproteobacteria closely related to sulfur-oxidizing endosymbionts associated with the mussels, as well as from Betaproteobacteria. We hypothesize that “Ca. Thiobarba” switched from the rTCA cycle to a fully functional CBB cycle during its evolution, by acquiring genes from multiple sources, including co-occurring symbionts. We also found key CBB cycle genes in free-living Campylobacterota, suggesting that the CBB cycle may be more widespread in this phylum than previously known. Metatranscriptomics and metaproteomics confirmed high expression of CBB cycle genes in mussel-associated “Ca. Thiobarba”. Direct stable isotope fingerprinting showed that “Ca. Thiobarba” has typical CBB signatures, suggesting that it uses this cycle for carbon fixation. Our discovery calls into question current assumptions about the distribution of carbon fixation pathways in microbial lineages, and the interpretation of stable isotope measurements in the environment.
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Seah BKB, Antony CP, Huettel B, Zarzycki J, Schada von Borzyskowski L, Erb TJ, Kouris A, Kleiner M, Liebeke M, Dubilier N, Gruber-Vodicka HR. Sulfur-Oxidizing Symbionts without Canonical Genes for Autotrophic CO 2 Fixation. mBio 2019; 10:e01112-19. [PMID: 31239380 PMCID: PMC6593406 DOI: 10.1128/mbio.01112-19] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 05/23/2019] [Indexed: 01/25/2023] Open
Abstract
Since the discovery of symbioses between sulfur-oxidizing (thiotrophic) bacteria and invertebrates at hydrothermal vents over 40 years ago, it has been assumed that autotrophic fixation of CO2 by the symbionts drives these nutritional associations. In this study, we investigated "Candidatus Kentron," the clade of symbionts hosted by Kentrophoros, a diverse genus of ciliates which are found in marine coastal sediments around the world. Despite being the main food source for their hosts, Kentron bacteria lack the key canonical genes for any of the known pathways for autotrophic carbon fixation and have a carbon stable isotope fingerprint that is unlike other thiotrophic symbionts from similar habitats. Our genomic and transcriptomic analyses instead found metabolic features consistent with growth on organic carbon, especially organic and amino acids, for which they have abundant uptake transporters. All known thiotrophic symbionts have converged on using reduced sulfur to gain energy lithotrophically, but they are diverse in their carbon sources. Some clades are obligate autotrophs, while many are mixotrophs that can supplement autotrophic carbon fixation with heterotrophic capabilities similar to those in Kentron. Here we show that Kentron bacteria are the only thiotrophic symbionts that appear to be entirely heterotrophic, unlike all other thiotrophic symbionts studied to date, which possess either the Calvin-Benson-Bassham or the reverse tricarboxylic acid cycle for autotrophy.IMPORTANCE Many animals and protists depend on symbiotic sulfur-oxidizing bacteria as their main food source. These bacteria use energy from oxidizing inorganic sulfur compounds to make biomass autotrophically from CO2, serving as primary producers for their hosts. Here we describe a clade of nonautotrophic sulfur-oxidizing symbionts, "Candidatus Kentron," associated with marine ciliates. They lack genes for known autotrophic pathways and have a carbon stable isotope fingerprint heavier than other symbionts from similar habitats. Instead, they have the potential to oxidize sulfur to fuel the uptake of organic compounds for heterotrophic growth, a metabolic mode called chemolithoheterotrophy that is not found in other symbioses. Although several symbionts have heterotrophic features to supplement primary production, in Kentron they appear to supplant it entirely.
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Affiliation(s)
| | | | - Bruno Huettel
- Max Planck Genome Centre Cologne, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Jan Zarzycki
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | | | - Tobias J Erb
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Angela Kouris
- Energy Bioengineering and Geomicrobiology Group, University of Calgary, Calgary, Alberta, Canada
| | - Manuel Kleiner
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina, USA
| | - Manuel Liebeke
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Nicole Dubilier
- Max Planck Institute for Marine Microbiology, Bremen, Germany
- MARUM, Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany
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Detection and Identification of Low-Abundant Proteins Using HPE Gels, Fluorescent Stains, and MALDI-ToF-ToF-MS. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2019; 1841:79-93. [PMID: 30259481 DOI: 10.1007/978-1-4939-8695-8_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Two-dimensional electrophoresis as a complementary approach to gel-free proteomic methods possesses the ability to separate physiologically important isoforms of proteins in an unbiased manner. Frequently, those isoforms are low-abundant regulators, and therefore, detection and identification of low-abundant proteins is highly necessary to exploit this advantage. We describe an experimental sequence of classical operations to process gels but optimized them, in order to identify each detectable protein spot on gel.
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Genetic Evidence for Two Carbon Fixation Pathways (the Calvin-Benson-Bassham Cycle and the Reverse Tricarboxylic Acid Cycle) in Symbiotic and Free-Living Bacteria. mSphere 2019; 4:4/1/e00394-18. [PMID: 30602523 PMCID: PMC6315080 DOI: 10.1128/msphere.00394-18] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Primary production on Earth is dependent on autotrophic carbon fixation, which leads to the incorporation of carbon dioxide into biomass. Multiple metabolic pathways have been described for autotrophic carbon fixation, but most autotrophic organisms were assumed to have the genes for only one of these pathways. Our finding of a cultivable bacterium with two carbon fixation pathways in its genome, the rTCA and the CBB cycle, opens the possibility to study the potential benefits of having these two pathways and the interplay between them. Additionally, this will allow the investigation of the unusual and potentially very efficient mechanism of electron flow that could drive the rTCA cycle in these autotrophs. Such studies will deepen our understanding of carbon fixation pathways and could provide new avenues for optimizing carbon fixation in biotechnological applications. Very few bacteria are able to fix carbon via both the reverse tricarboxylic acid (rTCA) and the Calvin-Benson-Bassham (CBB) cycles, such as symbiotic, sulfur-oxidizing bacteria that are the sole carbon source for the marine tubeworm Riftia pachyptila, the fastest-growing invertebrate. To date, the coexistence of these two carbon fixation pathways had not been found in a cultured bacterium and could thus not be studied in detail. Moreover, it was not clear if these two pathways were encoded in the same symbiont individual, or if two symbiont populations, each with one of the pathways, coexisted within tubeworms. With comparative genomics, we show that Thioflavicoccus mobilis, a cultured, free-living gammaproteobacterial sulfur oxidizer, possesses the genes for both carbon fixation pathways. Here, we also show that both the CBB and rTCA pathways are likely encoded in the genome of the sulfur-oxidizing symbiont of the tubeworm Escarpia laminata from deep-sea asphalt volcanoes in the Gulf of Mexico. Finally, we provide genomic and transcriptomic data suggesting a potential electron flow toward the rTCA cycle carboxylase 2-oxoglutarate:ferredoxin oxidoreductase, via a rare variant of NADH dehydrogenase/heterodisulfide reductase in the E. laminata symbiont. This electron-bifurcating complex, together with NAD(P)+ transhydrogenase and Na+ translocating Rnf membrane complexes, may improve the efficiency of the rTCA cycle in both the symbiotic and the free-living sulfur oxidizer. IMPORTANCE Primary production on Earth is dependent on autotrophic carbon fixation, which leads to the incorporation of carbon dioxide into biomass. Multiple metabolic pathways have been described for autotrophic carbon fixation, but most autotrophic organisms were assumed to have the genes for only one of these pathways. Our finding of a cultivable bacterium with two carbon fixation pathways in its genome, the rTCA and the CBB cycle, opens the possibility to study the potential benefits of having these two pathways and the interplay between them. Additionally, this will allow the investigation of the unusual and potentially very efficient mechanism of electron flow that could drive the rTCA cycle in these autotrophs. Such studies will deepen our understanding of carbon fixation pathways and could provide new avenues for optimizing carbon fixation in biotechnological applications.
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Taxonomic and functional heterogeneity of the gill microbiome in a symbiotic coastal mangrove lucinid species. ISME JOURNAL 2018; 13:902-920. [PMID: 30518817 PMCID: PMC6461927 DOI: 10.1038/s41396-018-0318-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 10/23/2018] [Accepted: 11/04/2018] [Indexed: 12/28/2022]
Abstract
Lucinidae clams harbor gammaproteobacterial thioautotrophic gill endosymbionts that are environmentally acquired. Thioautotrophic lucinid symbionts are related to metabolically similar symbionts associated with diverse marine host taxa and fall into three distinct phylogenetic clades. Most studies on the lucinid–bacteria chemosymbiosis have been done with seagrass-dwelling hosts, whose symbionts belong to the largest phylogenetic clade. In this study, we examined the taxonomy and functional repertoire of bacterial endosymbionts at an unprecedented resolution from Phacoides pectinatus retrieved from mangrove-lined coastal sediments, which are underrepresented in chemosymbiosis studies. The P. pectinatus thioautotrophic endosymbiont expressed metabolic gene variants for thioautotrophy, respiration, and nitrogen assimilation distinct from previously characterized lucinid thioautotrophic symbionts and other marine symbionts. At least two other bacterial species with different metabolisms were also consistently identified in the P. pectinatus gill microbiome, including a Kistimonas-like species and a Spirochaeta-like species. Bacterial transcripts involved in adhesion, growth, and virulence and mixotrophy were highly expressed, as were host-related hemoglobin and lysozyme transcripts indicative of sulfide/oxygen/CO2 transport and bactericidal activity. This study suggests the potential roles of P. pectinatus and its gill microbiome species in mangrove sediment biogeochemistry and offers insights into host and microbe metabolisms in the habitat.
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Li B, Li Z, Sun X, Wang Q, Xiao E, Sun W. DNA-SIP Reveals the Diversity of Chemolithoautotrophic Bacteria Inhabiting Three Different Soil Types in Typical Karst Rocky Desertification Ecosystems in Southwest China. MICROBIAL ECOLOGY 2018; 76:976-990. [PMID: 29728707 DOI: 10.1007/s00248-018-1196-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 04/16/2018] [Indexed: 06/08/2023]
Abstract
Autotrophs that inhabit soils receive less attention than their counterparts in other ecosystems, such as deep-sea and subsurface sediments, due to the low abundance of autotrophs in soils with high organic contents. However, the karst rocky desertification region is a unique ecosystem that may have a low level of organic compounds. Therefore, we propose that karst rocky desertification ecosystems may harbor diverse autotrophic microbial communities. In this study, DNA-SIP was employed to identify the chemolithoautotrophic bacteria inhabiting three soil types (i.e., grass, forest, and agriculture) of the karst rocky desertification ecosystems. The results indicated that potential chemolithoautotrophic population was observed in each soil type, even at different time points after amending 13C-NaHCO3, confirming our hypothesis that diverse autotrophs contribute to the carbon cycle in karst soils. Bacteria, such as Ralstonia, Ochrobactrum, Brevibacterium, Acinetobacter, and Corynebacterium, demonstrated their potential to assimilate inorganic carbon and reduce nitrate or thiosulfate as electron acceptors. Putative mixotrophs were identified by DNA-SIP as well, suggesting the metabolic versatility of soil microbiota. A co-occurrence network further indicated that autotrophs and heterotrophs may form associated communities to sustain the ecosystem function. Our current study revealed the metabolic diversity of autotrophic bacteria in soil habitats and demonstrated the potentially important role of chemoautotrophs in karst rocky desertification ecosystems.
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Affiliation(s)
- Baoqin Li
- Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental Science & Technology, 808 Tianyuan Road, Guangzhou, 510650, Guangdong, China
| | - Zhe Li
- Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental Science & Technology, 808 Tianyuan Road, Guangzhou, 510650, Guangdong, China
| | - Xiaoxu Sun
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Qi Wang
- Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental Science & Technology, 808 Tianyuan Road, Guangzhou, 510650, Guangdong, China
| | - Enzong Xiao
- Innovation Center and Key Laboratory of Waters Safety & Protection in the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China
| | - Weimin Sun
- Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental Science & Technology, 808 Tianyuan Road, Guangzhou, 510650, Guangdong, China.
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Khandavalli LVNS, Lodha T, Abdullah M, Guruprasad L, Chintalapati S, Chintalapati VR. Insights into the carbonic anhydrases and autotrophic carbon dioxide fixation pathways of high CO2 tolerant Rhodovulum viride JA756. Microbiol Res 2018; 215:130-140. [DOI: 10.1016/j.micres.2018.07.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 06/20/2018] [Accepted: 07/13/2018] [Indexed: 10/28/2022]
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Turner JW, Tallman JJ, Macias A, Pinnell LJ, Elledge NC, Nasr Azadani D, Nilsson WB, Paranjpye RN, Armbrust EV, Strom MS. Comparative Genomic Analysis of Vibrio diabolicus and Six Taxonomic Synonyms: A First Look at the Distribution and Diversity of the Expanded Species. Front Microbiol 2018; 9:1893. [PMID: 30158916 PMCID: PMC6104160 DOI: 10.3389/fmicb.2018.01893] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 07/27/2018] [Indexed: 11/13/2022] Open
Abstract
Vibrio is a diverse genus of Gammaproteobacteria autochthonous to marine environments worldwide. Vibrio diabolicus and V. antiquarius were originally isolated from deep-sea hydrothermal fields in the East Pacific Rise. These species are closely related to members of the Harveyi clade (e.g., V. alginolyticus and V. parahaemolyticus) that are commonly isolated from coastal systems. This study reports the discovery and draft genome sequence of a novel isolate (Vibrio sp. 939) cultured from Pacific oysters (Crassostrea gigas). Questions surrounding the identity of Vibrio sp. 939 motivated a genome-scale taxonomic analysis of the Harveyi clade. A 49-genome phylogeny based on 1,109 conserved coding sequences and a comparison of average nucleotide identity (ANI) values revealed a clear case of synonymy between Vibrio sp. 939, V. diabolicus Art-Gut C1 and CNCM I-1629, V. antiquarius EX25 and four V. alginolyticus strains (E0666, FF273, TS13, and V2). This discovery expands the V. diabolicus species and makes available six additional genomes for comparative genomic analyses. The distribution of the expanded species is thought to be global given the range of isolation sources (horse mackerel, seawater, sediment, dentex, oyster, artemia and polycheate) and origins (China, India, Greece, United States, East Pacific Rise, and Chile). A subsequent comparative genomic analysis of this new eight-genome subclade revealed a high degree of individual genome plasticity and a large repertoire of genes related to virulence and defense. These findings represent a significant revision to the understanding of V. diabolicus and V. antiquarius as both have long been regarded as distinct species. This first look at the expanded V. diabolicus subclade suggests that the distribution and diversity of this species mirrors that of other Harveyi clade species, which are notable for their ubiquity and diversity.
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Affiliation(s)
- Jeffrey W Turner
- Department of Life Sciences, Texas A&M University-Corpus Christi, Corpus Christi, TX, United States
| | - James J Tallman
- Department of Life Sciences, Texas A&M University-Corpus Christi, Corpus Christi, TX, United States
| | - Amanda Macias
- Department of Life Sciences, Texas A&M University-Corpus Christi, Corpus Christi, TX, United States
| | - Lee J Pinnell
- Department of Life Sciences, Texas A&M University-Corpus Christi, Corpus Christi, TX, United States
| | - Nicole C Elledge
- Department of Life Sciences, Texas A&M University-Corpus Christi, Corpus Christi, TX, United States
| | - Danial Nasr Azadani
- Department of Life Sciences, Texas A&M University-Corpus Christi, Corpus Christi, TX, United States
| | - William B Nilsson
- Division of Environmental and Fisheries Sciences, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA, United States
| | - Rohinee N Paranjpye
- Division of Environmental and Fisheries Sciences, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA, United States
| | - E V Armbrust
- Center for Environmental Genomics, School of Oceanography, University of Washington, Seattle, WA, United States
| | - Mark S Strom
- Division of Environmental and Fisheries Sciences, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA, United States
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Endosymbiont genomes yield clues of tubeworm success. ISME JOURNAL 2018; 12:2785-2795. [PMID: 30022157 PMCID: PMC6194059 DOI: 10.1038/s41396-018-0220-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 05/23/2018] [Accepted: 06/11/2018] [Indexed: 11/17/2022]
Abstract
Forty years after discovery of chemosynthetic symbiosis in the tubeworm Riftia pachyptila, how organisms maintain their unique host–symbiont associations at the cellular level is still largely unknown. Previous studies primarily focus on symbionts associated with host lineages living in hydrothermal vents. To understand physiological adaptations and evolution in these holobiont systems in markedly different habitats, we characterized four novel siboglinid-symbiont genomes spanning deep-sea seep and sedimented environments. Our comparative analyses suggest that all sampled siboglinid chemoautotrophic symbionts, except for frenulate symbionts, can use both rTCA and Calvin cycle for carbon fixation. We hypothesize that over evolutionary time siboglinids have been able to utilize different bacterial lineages allowing greater metabolic flexibility of carbon fixation (e.g., rTCA) enabling tubeworms to thrive in more reducing habitats, such as vents and seeps. Moreover, we show that sulfur metabolism and molecular mechanisms related to initial infection are remarkably conserved across chemoautotrophic symbionts in different habitats. Unexpectedly, we find that the ability to use hydrogen, as an additional energy source, is potentially more widespread than previously recognized. Our comparative genomic results help elucidate potential mechanisms used to allow chemosynthetically dependent holobionts adapt to, and evolve in, different environments.
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Onishi Y, Yamanaka T, Okumura T, Kawagucci S, Watanabe HK, Ohara Y. Evaluation of nutrient and energy sources of the deepest known serpentinite-hosted ecosystem using stable carbon, nitrogen, and sulfur isotopes. PLoS One 2018; 13:e0199000. [PMID: 29906282 PMCID: PMC6003682 DOI: 10.1371/journal.pone.0199000] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 05/30/2018] [Indexed: 11/26/2022] Open
Abstract
The Shinkai Seep Field (SSF) in the southern Mariana forearc discovered in 2010 is the deepest (~5,700 m in depth) known serpentinite-hosted ecosystem dominated by a vesicomyid clam, Calyptogena (Abyssogena) mariana. The pioneering study presumed that the animal communities are primary sustained by reducing fluid originated from the serpentinization of mantle peridotite. For understanding the nutrient and energy sources for the SSF community, this study conducted four expeditions to the SSF and collected additional animal samples such as polychaetes and crustaceans as well as sediments, fragments of chimneys developing on fissures of serpentinized peridotite, seeping fluid on the chimneys, and pore water within the chimneys. Geochemical analyses of seeping fluids on the chimneys and pore water of the chimneys revealed significantly high pH (~10) that suggest subseafloor serpentinization controlling fluid chemistry. Stable isotope systematics (carbon, nitrogen, and sulfur) among animals, inorganic molecules, and environmental organic matter suggest that the SSF animal community mostly relies on the chemosynthetic production while some organisms appear to partly benefit from photosynthetic production despite the great depth of SSF.
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Affiliation(s)
- Yuji Onishi
- Graduate school of Natural Science and Technology, Okayama University, Kita-ku, Okayama, Okayama, Japan
- * E-mail:
| | - Toshiro Yamanaka
- Graduate school of Natural Science and Technology, Okayama University, Kita-ku, Okayama, Okayama, Japan
| | - Tomoyo Okumura
- Department of Subsurface Geobiological Analysis and Research (D-SUGAR), Japan Agency for Marine-Earth Science and Technology, Yokosuka, Kanagawa, Japan
| | - Shinsuke Kawagucci
- Department of Subsurface Geobiological Analysis and Research (D-SUGAR), Japan Agency for Marine-Earth Science and Technology, Yokosuka, Kanagawa, Japan
| | - Hiromi Kayama Watanabe
- Department of Marine Biodiversity Research, Japan Agency for Marine-Earth Science and Technology, Yokosuka, Kanagawa, Japan
| | - Yasuhiko Ohara
- Department of Subsurface Geobiological Analysis and Research (D-SUGAR), Japan Agency for Marine-Earth Science and Technology, Yokosuka, Kanagawa, Japan
- Hydrographic and Oceanographic Department of Japan, Kasumigaseki, Chiyoda-ku, Tokyo, Japan
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Hinzke T, Kleiner M, Markert S. Centrifugation-Based Enrichment of Bacterial Cell Populations for Metaproteomic Studies on Bacteria-Invertebrate Symbioses. Methods Mol Biol 2018; 1841:319-334. [PMID: 30259496 DOI: 10.1007/978-1-4939-8695-8_22] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Owing to high sample complexity, metaproteomic investigations on bacteria-animal symbioses with two or more uncultured partners can be challenging. A selective isolation or enrichment of distinct (sub-)populations within those consortia can solve this problem. Subsequent discrete proteomic analyses benefit from increased sample purity and higher proteome coverage for each of the individual organisms. Here, we describe centrifugation-based methods that allow for a separation of the host and its bacterial symbiont population(s), or even for an enrichment of distinct symbiotic cell cycle stages in the deep-sea mussels Bathymodiolus azoricus and B. thermophilus, the gutless oligochaete Olavius algarvensis and the deep-sea tube worm Riftia pachyptila, respectively.
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Affiliation(s)
| | - Manuel Kleiner
- Department of Plant & Microbial Biology, North Carolina State University, Raleigh, NC, USA
| | - Stephanie Markert
- Institute of Marine Biotechnology, Greifswald, Germany.
- Department of Pharmaceutical Biotechnology, Institute of Pharmacy, University of Greifswald, Greifswald, Germany.
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Wöhlbrand L, Feenders C, Nachbaur J, Freund H, Engelen B, Wilkes H, Brumsack HJ, Rabus R. Impact of Extraction Methods on the Detectable Protein Complement of Metaproteomic Analyses of Marine Sediments. Proteomics 2017; 17. [DOI: 10.1002/pmic.201700241] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 08/21/2017] [Indexed: 11/11/2022]
Affiliation(s)
- Lars Wöhlbrand
- General and Molecular Microbiology; Institute for Chemistry and Biology of the Marine Environment (ICBM); Carl von Ossietzky University of Oldenburg; Oldenburg Germany
| | - Christoph Feenders
- Mathematical Modelling; Institute for Chemistry and Biology of the Marine Environment (ICBM); Carl von Ossietzky University of Oldenburg; Oldenburg Germany
| | - Jessica Nachbaur
- General and Molecular Microbiology; Institute for Chemistry and Biology of the Marine Environment (ICBM); Carl von Ossietzky University of Oldenburg; Oldenburg Germany
| | - Holger Freund
- Geoecology; Institute for Chemistry and Biology of the Marine Environment (ICBM); Carl von Ossietzky University of Oldenburg; Oldenburg Germany
| | - Bert Engelen
- Paleomicrobiology; Institute for Chemistry and Biology of the Marine Environment (ICBM); Carl von Ossietzky University of Oldenburg; Oldenburg Germany
| | - Heinz Wilkes
- Organic Geochemistry; Institute for Chemistry and Biology of the Marine Environment (ICBM); Carl von Ossietzky University of Oldenburg; Oldenburg Germany
| | - Hans-Jürgen Brumsack
- Microbiogeochemistry; Institute for Chemistry and Biology of the Marine Environment (ICBM); Carl von Ossietzky University of Oldenburg; Oldenburg Germany
| | - Ralf Rabus
- General and Molecular Microbiology; Institute for Chemistry and Biology of the Marine Environment (ICBM); Carl von Ossietzky University of Oldenburg; Oldenburg Germany
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Thiel V, Hügler M, Ward DM, Bryant DA. The Dark Side of the Mushroom Spring Microbial Mat: Life in the Shadow of Chlorophototrophs. II. Metabolic Functions of Abundant Community Members Predicted from Metagenomic Analyses. Front Microbiol 2017. [PMID: 28634470 PMCID: PMC5459899 DOI: 10.3389/fmicb.2017.00943] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microbial mat communities in the effluent channels of Octopus and Mushroom Springs within the Lower Geyser Basin of Yellowstone National Park have been extensively characterized. Previous studies have focused on the chlorophototrophic organisms of the phyla Cyanobacteria and Chloroflexi. However, the diversity and metabolic functions of the other portion of the community in the microoxic/anoxic region of the mat are poorly understood. We recently described the diverse but extremely uneven microbial assemblage in the undermat of Mushroom Spring based on 16S rRNA amplicon sequences, which was dominated by Roseiflexus members, filamentous anoxygenic chlorophototrophs. In this study, we analyzed the orange-colored undermat portion of the community of Mushroom Spring mats in a genome-centric approach and discuss the metabolic potentials of the major members. Metagenome binning recovered partial genomes of all abundant community members, ranging in completeness from ~28 to 96%, and allowed affiliation of function with taxonomic identity even for representatives of novel and Candidate phyla. Less complete metagenomic bins correlated with high microdiversity. The undermat portion of the community was found to be a mixture of phototrophic and chemotrophic organisms, which use bicarbonate as well as organic carbon sources derived from different cell components and fermentation products. The presence of rhodopsin genes in many taxa strengthens the hypothesis that light energy is of major importance. Evidence for the usage of all four bacterial carbon fixation pathways was found in the metagenome. Nitrogen fixation appears to be limited to Synechococcus spp. in the upper mat layer and Thermodesulfovibrio sp. in the undermat, and nitrate/nitrite metabolism was limited. A closed sulfur cycle is indicated by biological sulfate reduction combined with the presence of genes for sulfide oxidation mainly in phototrophs. Finally, a variety of undermat microorganisms have genes for hydrogen production and consumption, which leads to the observed diel hydrogen concentration patterns.
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Affiliation(s)
- Vera Thiel
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University ParkPA, United States
| | - Michael Hügler
- Department Microbiology and Molecular Biology, DVGW-Technologiezentrum WasserKarlsruhe, Germany
| | - David M Ward
- Department of Land Resources and Environmental Sciences, Montana State UniversityBozeman, MT, United States
| | - Donald A Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University ParkPA, United States.,Department of Chemistry and Biochemistry, Montana State UniversityBozeman, MT, United States
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45
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Giovannelli D, Sievert SM, Hügler M, Markert S, Becher D, Schweder T, Vetriani C. Insight into the evolution of microbial metabolism from the deep-branching bacterium, Thermovibrio ammonificans. eLife 2017; 6. [PMID: 28436819 PMCID: PMC5441870 DOI: 10.7554/elife.18990] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 04/23/2017] [Indexed: 01/10/2023] Open
Abstract
Anaerobic thermophiles inhabit relic environments that resemble the early Earth. However, the lineage of these modern organisms co-evolved with our planet. Hence, these organisms carry both ancestral and acquired genes and serve as models to reconstruct early metabolism. Based on comparative genomic and proteomic analyses, we identified two distinct groups of genes in Thermovibrio ammonificans: the first codes for enzymes that do not require oxygen and use substrates of geothermal origin; the second appears to be a more recent acquisition, and may reflect adaptations to cope with the rise of oxygen on Earth. We propose that the ancestor of the Aquificae was originally a hydrogen oxidizing, sulfur reducing bacterium that used a hybrid pathway for CO2 fixation. With the gradual rise of oxygen in the atmosphere, more efficient terminal electron acceptors became available and this lineage acquired genes that increased its metabolic flexibility while retaining ancestral metabolic traits. DOI:http://dx.doi.org/10.7554/eLife.18990.001 Life may have arisen on our planet as far back as four billion years ago. Unlike today, the Earth’s atmosphere at the time had no oxygen and an abundance of volcanic emissions including hydrogen, carbon dioxide and sulfur gases. These dramatic differences have led scientists to wonder: how did the ancient microorganisms that inhabited our early planet make a living? And how has microbial life co-evolved with the Earth? One way to answer these questions is to study bacteria that live today in environments that resemble the early Earth. Deep-sea hydrothermal vents are regions of the deep ocean where active volcanic processes recreate primordial conditions. These habitats support microorganisms that are highly adapted to live off hydrogen, carbon dioxide and sulfur gases, and studying these modern-day microorganisms could give insights into the earliest life on Earth. Thermovibrio ammonificans is a bacterium that was obtained from an underwater volcanic system in the East Pacific. Giovannelli et al. have now asked if T. ammonificans might have inherited some of its genetic traits from a long-gone ancestor that also thrived off volcanic gases. The genetic makeup of this microorganism was examined for genes that would help it thrive at a deep-sea hydrothermal vent. Next, Giovannelli et al. compared these genes to related copies in other species of bacteria to reconstruct how the metabolism of T. ammonificans might have changed over time. This approach identified a group of likely ancient genesthat allow a microorganism to use chemicals like hydrogen, carbon dioxide and sulfur to fuel its growth and metabolism. These findings support the hypothesis that an ancestor of T. ammonificans could live off volcanic gases and that the core set of genes involved in those activities had been passed on, through the generations, to this modern-day microorganism. Giovannelli et al. also identified a second group of genes in T. ammonificans that indicate that this bacterium also co-evolved with Earth’s changing conditions, in particular the rise in the concentration of oxygen. The findings of Giovannelli et al. provide insight into how the metabolism of microbes has co-evolved with the Earth’s changing conditions, and will allow others to formulate new hypotheses that can be tested in laboratory experiments. DOI:http://dx.doi.org/10.7554/eLife.18990.002
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Affiliation(s)
- Donato Giovannelli
- Institute of Earth, Ocean and Atmospheric Sciences, Rutgers University, New Brunswick, United States.,Institute of Marine Science, National Research Council of Italy, Ancona, Italy.,Program in Interdisciplinary Studies, Institute for Advanced Studies, Princeton, United States.,Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
| | - Stefan M Sievert
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, United States
| | | | - Stephanie Markert
- Pharmaceutical Biotechnology, Institute of Pharmacy, Institute of Pharmacy, Ernst-Moritz-Arndt-University Greifswald, Greifswald, Germany
| | - Dörte Becher
- Institute for Microbiology, Ernst-Moritz-Arndt-University Greifswald, Greifswald, Germany
| | - Thomas Schweder
- Pharmaceutical Biotechnology, Institute of Pharmacy, Institute of Pharmacy, Ernst-Moritz-Arndt-University Greifswald, Greifswald, Germany
| | - Costantino Vetriani
- Institute of Earth, Ocean and Atmospheric Sciences, Rutgers University, New Brunswick, United States.,Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, United States
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46
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Genome Reduction and Microbe-Host Interactions Drive Adaptation of a Sulfur-Oxidizing Bacterium Associated with a Cold Seep Sponge. mSystems 2017; 2:mSystems00184-16. [PMID: 28345060 PMCID: PMC5361782 DOI: 10.1128/msystems.00184-16] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 02/09/2017] [Indexed: 12/20/2022] Open
Abstract
Sponges and their symbionts are important players in the biogeochemical cycles of marine environments. As a unique habitat within marine ecosystems, cold seeps have received considerable interest in recent years. This study explores the lifestyle of a new symbiotic SOB in a cold seep sponge. The results demonstrate that both this sponge symbiont and endosymbionts in deep-sea clams employ similar strategies of genome reduction. However, this bacterium has retained unique functions for immunity and defense. Thus, the functional features are determined by both the symbiotic relationship and host type. Moreover, analyses of the genome of an AOA suggest that microbes play different roles in biochemical cycles in the sponge body. Our findings provide new insights into invertebrate-associated bacteria in cold seep environments. As the most ancient metazoan, sponges have established close relationships with particular microbial symbionts. However, the characteristics and physiology of thioautotrophic symbionts in deep-sea sponges are largely unknown. Using a tailored “differential coverage binning” method on 22-Gb metagenomic sequences, we recovered the nearly complete genome of a sulfur-oxidizing bacterium (SOB) that dominates the microbiota of the cold seep sponge Suberites sp. Phylogenetic analyses suggested that this bacterium (an unclassified gammaproteobacterium termed “Gsub”) may represent a new deep-sea SOB group. Microscopic observations suggest that Gsub is probably an extracellular symbiont. Gsub has complete sulfide oxidation and carbon fixation pathways, suggesting a chemoautotrophic lifestyle. Comparative genomics with other sponge-associated SOB and free-living SOB revealed significant genome reduction in Gsub, characterized by the loss of genes for carbohydrate metabolism, motility, DNA repair, and osmotic stress response. Intriguingly, this scenario of genome reduction is highly similar to those of the endosymbionts in deep-sea clams. However, Gsub has retained genes for phage defense and protein secretion, with the latter potentially playing a role in interactions with the sponge host. In addition, we recovered the genome of an ammonia-oxidizing archaeon (AOA), which may carry out ammonia oxidation and carbon fixation within the sponge body. IMPORTANCE Sponges and their symbionts are important players in the biogeochemical cycles of marine environments. As a unique habitat within marine ecosystems, cold seeps have received considerable interest in recent years. This study explores the lifestyle of a new symbiotic SOB in a cold seep sponge. The results demonstrate that both this sponge symbiont and endosymbionts in deep-sea clams employ similar strategies of genome reduction. However, this bacterium has retained unique functions for immunity and defense. Thus, the functional features are determined by both the symbiotic relationship and host type. Moreover, analyses of the genome of an AOA suggest that microbes play different roles in biochemical cycles in the sponge body. Our findings provide new insights into invertebrate-associated bacteria in cold seep environments.
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47
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Seston SL, Beinart RA, Sarode N, Shockey AC, Ranjan P, Ganesh S, Girguis PR, Stewart FJ. Metatranscriptional Response of Chemoautotrophic Ifremeria nautilei Endosymbionts to Differing Sulfur Regimes. Front Microbiol 2016; 7:1074. [PMID: 27486438 PMCID: PMC4949241 DOI: 10.3389/fmicb.2016.01074] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 06/27/2016] [Indexed: 12/26/2022] Open
Abstract
Endosymbioses between animals and chemoautotrophic bacteria are ubiquitous at hydrothermal vents. These environments are distinguished by high physico-chemical variability, yet we know little about how these symbioses respond to environmental fluctuations. We therefore examined how the γ-proteobacterial symbionts of the vent snail Ifremeria nautilei respond to changes in sulfur geochemistry. Via shipboard high-pressure incubations, we subjected snails to 105 μM hydrogen sulfide (LS), 350 μM hydrogen sulfide (HS), 300 μM thiosulfate (TS) and seawater without any added inorganic electron donor (ND). While transcript levels of sulfur oxidation genes were largely consistent across treatments, HS and TS treatments stimulated genes for denitrification, nitrogen assimilation, and CO2 fixation, coincident with previously reported enhanced rates of inorganic carbon incorporation and sulfur oxidation in these treatments. Transcripts for genes mediating oxidative damage were enriched in the ND and LS treatments, potentially due to a reduction in O2 scavenging when electron donors were scarce. Oxidative TCA cycle gene transcripts were also more abundant in ND and LS treatments, suggesting that I. nautilei symbionts may be mixotrophic when inorganic electron donors are limiting. These data reveal the extent to which I. nautilei symbionts respond to changes in sulfur concentration and species, and, interpreted alongside coupled biochemical metabolic rates, identify gene targets whose expression patterns may be predictive of holobiont physiology in environmental samples.
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Affiliation(s)
| | - Roxanne A Beinart
- Department of Organismic and Evolutionary Biology, Harvard University Cambridge, MA, USA
| | - Neha Sarode
- School of Biology, Georgia Institute of Technology Atlanta, GA, USA
| | - Abigail C Shockey
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison Madison, WI, USA
| | - Piyush Ranjan
- School of Biology, Georgia Institute of Technology Atlanta, GA, USA
| | - Sangita Ganesh
- School of Biology, Georgia Institute of Technology Atlanta, GA, USA
| | - Peter R Girguis
- Department of Organismic and Evolutionary Biology, Harvard University Cambridge, MA, USA
| | - Frank J Stewart
- School of Biology, Georgia Institute of Technology Atlanta, GA, USA
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48
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Probst AJ, Castelle CJ, Singh A, Brown CT, Anantharaman K, Sharon I, Hug LA, Burstein D, Emerson JB, Thomas BC, Banfield JF. Genomic resolution of a cold subsurface aquifer community provides metabolic insights for novel microbes adapted to high CO 2 concentrations. Environ Microbiol 2016; 19:459-474. [PMID: 27112493 DOI: 10.1111/1462-2920.13362] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
As in many deep underground environments, the microbial communities in subsurface high-CO2 ecosystems remain relatively unexplored. Recent investigations based on single-gene assays revealed a remarkable variety of organisms from little studied phyla in Crystal Geyser (Utah, USA), a site where deeply sourced CO2 -saturated fluids are erupted at the surface. To provide genomic resolution of the metabolisms of these organisms, we used a novel metagenomic approach to recover 227 high-quality genomes from 150 microbial species affiliated with 46 different phylum-level lineages. Bacteria from two novel phylum-level lineages have the capacity for CO2 fixation. Analyses of carbon fixation pathways in all studied organisms revealed that the Wood-Ljungdahl pathway and the Calvin-Benson-Bassham Cycle occurred with the highest frequency, whereas the reverse TCA cycle was little used. We infer that this, and selection for form II RuBisCOs, are adaptions to high CO2 -concentrations. However, many autotrophs can also grow mixotrophically, a strategy that confers metabolic versatility. The assignment of 156 hydrogenases to 90 different organisms suggests that H2 is an important inter-species energy currency even under gaseous CO2 -saturation. Overall, metabolic analyses at the organism level provided insight into the biochemical cycles that support subsurface life under the extreme condition of CO2 saturation.
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Affiliation(s)
- Alexander J Probst
- Department of Earth and Planetary Sciences, University of California, Berkeley, 307 McCone Hall, CA, 94720, USA
| | - Cindy J Castelle
- Department of Earth and Planetary Sciences, University of California, Berkeley, 307 McCone Hall, CA, 94720, USA
| | - Andrea Singh
- Department of Earth and Planetary Sciences, University of California, Berkeley, 307 McCone Hall, CA, 94720, USA
| | - Christopher T Brown
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Karthik Anantharaman
- Department of Earth and Planetary Sciences, University of California, Berkeley, 307 McCone Hall, CA, 94720, USA
| | - Itai Sharon
- Department of Earth and Planetary Sciences, University of California, Berkeley, 307 McCone Hall, CA, 94720, USA
| | - Laura A Hug
- Department of Earth and Planetary Sciences, University of California, Berkeley, 307 McCone Hall, CA, 94720, USA
| | - David Burstein
- Department of Earth and Planetary Sciences, University of California, Berkeley, 307 McCone Hall, CA, 94720, USA
| | - Joanne B Emerson
- Department of Earth and Planetary Sciences, University of California, Berkeley, 307 McCone Hall, CA, 94720, USA
| | - Brian C Thomas
- Department of Earth and Planetary Sciences, University of California, Berkeley, 307 McCone Hall, CA, 94720, USA
| | - Jillian F Banfield
- Department of Earth and Planetary Sciences, University of California, Berkeley, 307 McCone Hall, CA, 94720, USA.,Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, USA.,Earth Science Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, USA
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49
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Winkel M, Salman-Carvalho V, Woyke T, Richter M, Schulz-Vogt HN, Flood BE, Bailey JV, Mußmann M. Single-cell Sequencing of Thiomargarita Reveals Genomic Flexibility for Adaptation to Dynamic Redox Conditions. Front Microbiol 2016; 7:964. [PMID: 27446006 PMCID: PMC4914600 DOI: 10.3389/fmicb.2016.00964] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Accepted: 06/03/2016] [Indexed: 11/25/2022] Open
Abstract
Large, colorless sulfur-oxidizing bacteria (LSB) of the family Beggiatoaceae form thick mats at sulfidic sediment surfaces, where they efficiently detoxify sulfide before it enters the water column. The genus Thiomargarita harbors the largest known free-living bacteria with cell sizes of up to 750 μm in diameter. In addition to their ability to oxidize reduced sulfur compounds, some Thiomargarita spp. are known to store large amounts of nitrate, phosphate and elemental sulfur internally. To date little is known about their energy yielding metabolic pathways, and how these pathways compare to other Beggiatoaceae. Here, we present a draft single-cell genome of a chain-forming “Candidatus Thiomargarita nelsonii Thio36”, and conduct a comparative analysis to five draft and one full genome of other members of the Beggiatoaceae. “Ca. T. nelsonii Thio36” is able to respire nitrate to both ammonium and dinitrogen, which allows them to flexibly respond to environmental changes. Genes for sulfur oxidation and inorganic carbon fixation confirmed that “Ca. T. nelsonii Thio36” can function as a chemolithoautotroph. Carbon can be fixed via the Calvin–Benson–Bassham cycle, which is common among the Beggiatoaceae. In addition we found key genes of the reductive tricarboxylic acid cycle that point toward an alternative CO2 fixation pathway. Surprisingly, “Ca. T. nelsonii Thio36” also encodes key genes of the C2-cycle that convert 2-phosphoglycolate to 3-phosphoglycerate during photorespiration in higher plants and cyanobacteria. Moreover, we identified a novel trait of a flavin-based energy bifurcation pathway coupled to a Na+-translocating membrane complex (Rnf). The coupling of these pathways may be key to surviving long periods of anoxia. As other Beggiatoaceae “Ca. T. nelsonii Thio36” encodes many genes similar to those of (filamentous) cyanobacteria. In summary, the genome of “Ca. T. nelsonii Thio36” provides additional insight into the ecology of giant sulfur-oxidizing bacteria, and reveals unique genomic features for the Thiomargarita lineage within the Beggiatoaceae.
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Affiliation(s)
- Matthias Winkel
- Molecular Ecology Group, Department of Molecular Ecology, Max Planck Institute for Marine MicrobiologyBremen, Germany; Section Geomicrobiology, GFZ German Research Centre for Geoscience, Helmholtz Centre PotsdamPotsdam, Germany
| | - Verena Salman-Carvalho
- HGF MPG Joint Research Group for Deep-sea Ecology and Technology, Max Planck Institute for Marine Microbiology Bremen, Germany
| | - Tanja Woyke
- Department of Energy Joint Genome Institute, Walnut Creek CA, USA
| | - Michael Richter
- Microbial Genomics and Bioinformatics Group, Department of Molecular Ecology, Max Planck Institute for Marine Microbiology Bremen, Germany
| | | | - Beverly E Flood
- Department of Earth Sciences, University of Minnesota, Minneapolis MN, USA
| | - Jake V Bailey
- Department of Earth Sciences, University of Minnesota, Minneapolis MN, USA
| | - Marc Mußmann
- Molecular Ecology Group, Department of Molecular Ecology, Max Planck Institute for Marine Microbiology Bremen, Germany
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50
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Imhoff JF. New Dimensions in Microbial Ecology-Functional Genes in Studies to Unravel the Biodiversity and Role of Functional Microbial Groups in the Environment. Microorganisms 2016; 4:microorganisms4020019. [PMID: 27681913 PMCID: PMC5029485 DOI: 10.3390/microorganisms4020019] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 05/20/2016] [Accepted: 05/20/2016] [Indexed: 12/11/2022] Open
Abstract
During the past decades, tremendous advances have been made in the possibilities to study the diversity of microbial communities in the environment. The development of methods to study these communities on the basis of 16S rRNA gene sequences analysis was a first step into the molecular analysis of environmental communities and the study of biodiversity in natural habitats. A new dimension in this field was reached with the introduction of functional genes of ecological importance and the establishment of genetic tools to study the diversity of functional microbial groups and their responses to environmental factors. Functional gene approaches are excellent tools to study the diversity of a particular function and to demonstrate changes in the composition of prokaryote communities contributing to this function. The phylogeny of many functional genes largely correlates with that of the 16S rRNA gene, and microbial species may be identified on the basis of functional gene sequences. Functional genes are perfectly suited to link culture-based microbiological work with environmental molecular genetic studies. In this review, the development of functional gene studies in environmental microbiology is highlighted with examples of genes relevant for important ecophysiological functions. Examples are presented for bacterial photosynthesis and two types of anoxygenic phototrophic bacteria, with genes of the Fenna-Matthews-Olson-protein (fmoA) as target for the green sulfur bacteria and of two reaction center proteins (pufLM) for the phototrophic purple bacteria, with genes of adenosine-5'phosphosulfate (APS) reductase (aprA), sulfate thioesterase (soxB) and dissimilatory sulfite reductase (dsrAB) for sulfur oxidizing and sulfate reducing bacteria, with genes of ammonia monooxygenase (amoA) for nitrifying/ammonia-oxidizing bacteria, with genes of particulate nitrate reductase and nitrite reductases (narH/G, nirS, nirK) for denitrifying bacteria and with genes of methane monooxygenase (pmoA) for methane oxidizing bacteria.
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Affiliation(s)
- Johannes F Imhoff
- GEOMAR Helmholtz-Zentrum für Ozeanforschung, Düsternbrooker Weg 20, D-24105 Kiel, Germany.
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