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Rubin-Blum M, Makovsky Y, Rahav E, Belkin N, Antler G, Sisma-Ventura G, Herut B. Active microbial communities facilitate carbon turnover in brine pools found in the deep Southeastern Mediterranean Sea. MARINE ENVIRONMENTAL RESEARCH 2024; 198:106497. [PMID: 38631226 DOI: 10.1016/j.marenvres.2024.106497] [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: 01/14/2024] [Revised: 04/05/2024] [Accepted: 04/07/2024] [Indexed: 04/19/2024]
Abstract
Discharge of gas-rich brines fuels productive chemosynthetic ecosystems in the deep sea. In these salty, methanic and sulfidic brines, microbial communities adapt to specific niches along the physicochemical gradients. However, the molecular mechanisms that underpin these adaptations are not fully known. Using metagenomics, we investigated the dense (∼106 cell ml-1) microbial communities that occupy small deep-sea brine pools found in the Southeastern Mediterranean Sea (1150 m water depth, ∼22 °C, ∼60 PSU salinity, sulfide, methane, ammonia reaching millimolar levels, and oxygen usually depleted), reaching high productivity rates of 685 μg C L-1 d-1 ex-situ. We curated 266 metagenome-assembled genomes of bacteria and archaea from the several pools and adjacent sediment-water interface, highlighting the dominance of a single Sulfurimonas, which likely fuels its autotrophy using sulfide oxidation or inorganic sulfur disproportionation. This lineage may be dominant in its niche due to genome streamlining, limiting its metabolic repertoire, particularly by using a single variant of sulfide: quinone oxidoreductase. These primary producers co-exist with ANME-2c archaea that catalyze the anaerobic oxidation of methane. Other lineages can degrade the necromass aerobically (Halomonas and Alcanivorax), or anaerobically through fermentation of macromolecules (e.g., Caldatribacteriota, Bipolaricaulia, Chloroflexota, etc). These low-abundance organisms likely support the autotrophs, providing energy-rich H2, and vital organics such as vitamin B12.
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Affiliation(s)
- Maxim Rubin-Blum
- National Institute of Oceanography, Israel Oceanographic and Limnological Research, Haifa, Israel; The Department of Marine Biology, Charney School of Marine Sciences, University of Haifa, Haifa, Israel.
| | - Yizhaq Makovsky
- The Dr. Moses Strauss Department of Marine Geosciences, Charney School of Marine Sciences , University of Haifa, Haifa, Israel; The Hatter Department of Marine Technologies, Charney School of Marine Sciences, University of Haifa, Haifa, Israel
| | - Eyal Rahav
- National Institute of Oceanography, Israel Oceanographic and Limnological Research, Haifa, Israel
| | - Natalia Belkin
- National Institute of Oceanography, Israel Oceanographic and Limnological Research, Haifa, Israel
| | - Gilad Antler
- Department of Earth and Environmental Sciences, Ben-Gurion University of the Negev, Be'er Sheva, Israel; The Interuniversity Institute for Marine Sciences, Eilat, Israel
| | - Guy Sisma-Ventura
- National Institute of Oceanography, Israel Oceanographic and Limnological Research, Haifa, Israel
| | - Barak Herut
- National Institute of Oceanography, Israel Oceanographic and Limnological Research, Haifa, Israel; The Dr. Moses Strauss Department of Marine Geosciences, Charney School of Marine Sciences , University of Haifa, Haifa, Israel
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2
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Mitchell JH, Freedman AH, Delaney JA, Girguis PR. Co-expression analysis reveals distinct alliances around two carbon fixation pathways in hydrothermal vent symbionts. Nat Microbiol 2024; 9:1526-1539. [PMID: 38839975 DOI: 10.1038/s41564-024-01704-y] [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: 06/18/2023] [Accepted: 04/19/2024] [Indexed: 06/07/2024]
Abstract
Most autotrophic organisms possess a single carbon fixation pathway. The chemoautotrophic symbionts of the hydrothermal vent tubeworm Riftia pachyptila, however, possess two functional pathways: the Calvin-Benson-Bassham (CBB) and the reductive tricarboxylic acid (rTCA) cycles. How these two pathways are coordinated is unknown. Here we measured net carbon fixation rates, transcriptional/metabolic responses and transcriptional co-expression patterns of Riftia pachyptila endosymbionts by incubating tubeworms collected from the East Pacific Rise at environmental pressures, temperature and geochemistry. Results showed that rTCA and CBB transcriptional patterns varied in response to different geochemical regimes and that each pathway is allied to specific metabolic processes; the rTCA is allied to hydrogenases and dissimilatory nitrate reduction, whereas the CBB is allied to sulfide oxidation and assimilatory nitrate reduction, suggesting distinctive yet complementary roles in metabolic function. Furthermore, our network analysis implicates the rTCA and a group 1e hydrogenase as key players in the physiological response to limitation of sulfide and oxygen. Net carbon fixation rates were also exemplary, and accordingly, we propose that co-activity of CBB and rTCA may be an adaptation for maintaining high carbon fixation rates, conferring a fitness advantage in dynamic vent environments.
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Zhang N, Chen K, Wang X, Ji W, Yang Z, Wang X, Li J. Response Mechanism of cbbM Carbon Sequestration Microbial Community Characteristics in Different Wetland Types in Qinghai Lake. BIOLOGY 2024; 13:333. [PMID: 38785815 PMCID: PMC11117618 DOI: 10.3390/biology13050333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2024] [Revised: 05/08/2024] [Accepted: 05/09/2024] [Indexed: 05/25/2024]
Abstract
Carbon-sequestering microorganisms play an important role in the carbon cycle of wetland ecosystems. However, the response mechanism of carbon-sequestering microbial communities to wetland type changes and their relationship with soil carbon remain unclear. To explore these differences and identify the main influencing factors, this study selected marsh wetlands, river wetlands and lakeside wetlands around Qinghai Lake as research subjects. High-throughput sequencing was employed to analyze the functional gene cbbM of carbon-sequestering microorganisms. The results revealed that the alpha diversity of cbbM carbon-sequestering microorganisms mirrored the trend in total carbon content, with the highest diversity observed in marsh wetlands and the lowest in lakeside wetlands. The dominant bacterial phylum was Proteobacteria, with prevalent genera including Thiothrix, Acidithiobacillus, and Thiodictyon. Acidithiobacillus served as a biomarker in lakeside wetlands, while two other genera were indicative of marsh wetlands. The hierarchical partitioning analysis indicated that the diversity of cbbM carbon-fixing microorganisms was primarily influenced by the total nitrogen content, while the community structure was significantly affected by the soil total carbon content. Moreover, an increased soil temperature and humidity were found to favor the carbon fixation processes of Thiomicrospira, Thiomonas, Polaromonas, and Acidithiobacillus. In summary, changes in wetland types seriously affected the characteristics of cbbM carbon sequestration in microbial communities, and a warm and humid climate may be conducive to wetland carbon sequestration.
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Affiliation(s)
- Ni Zhang
- Qinghai Province Key Laboratory of Physical Geography and Environmental Process, College of Geographical Science, Qinghai Normal University, Xining 810008, China; (N.Z.); (X.W.); (W.J.); (Z.Y.); (X.W.)
- Key Laboratory of Tibetan Plateau Land Surface Processes and Ecological Conservation (Ministry of Education), Qinghai Normal University, Xining 810008, China
- National Positioning Observation and Research Station of Qinghai Lake Wetland Ecosystem in Qinghai, National Forestry and Grassland Administration, Haibei 812300, China
| | - Kelong Chen
- Qinghai Province Key Laboratory of Physical Geography and Environmental Process, College of Geographical Science, Qinghai Normal University, Xining 810008, China; (N.Z.); (X.W.); (W.J.); (Z.Y.); (X.W.)
- Key Laboratory of Tibetan Plateau Land Surface Processes and Ecological Conservation (Ministry of Education), Qinghai Normal University, Xining 810008, China
- National Positioning Observation and Research Station of Qinghai Lake Wetland Ecosystem in Qinghai, National Forestry and Grassland Administration, Haibei 812300, China
| | - Xinye Wang
- Qinghai Province Key Laboratory of Physical Geography and Environmental Process, College of Geographical Science, Qinghai Normal University, Xining 810008, China; (N.Z.); (X.W.); (W.J.); (Z.Y.); (X.W.)
- Key Laboratory of Tibetan Plateau Land Surface Processes and Ecological Conservation (Ministry of Education), Qinghai Normal University, Xining 810008, China
- National Positioning Observation and Research Station of Qinghai Lake Wetland Ecosystem in Qinghai, National Forestry and Grassland Administration, Haibei 812300, China
| | - Wei Ji
- Qinghai Province Key Laboratory of Physical Geography and Environmental Process, College of Geographical Science, Qinghai Normal University, Xining 810008, China; (N.Z.); (X.W.); (W.J.); (Z.Y.); (X.W.)
- Key Laboratory of Tibetan Plateau Land Surface Processes and Ecological Conservation (Ministry of Education), Qinghai Normal University, Xining 810008, China
- National Positioning Observation and Research Station of Qinghai Lake Wetland Ecosystem in Qinghai, National Forestry and Grassland Administration, Haibei 812300, China
| | - Ziwei Yang
- Qinghai Province Key Laboratory of Physical Geography and Environmental Process, College of Geographical Science, Qinghai Normal University, Xining 810008, China; (N.Z.); (X.W.); (W.J.); (Z.Y.); (X.W.)
- Key Laboratory of Tibetan Plateau Land Surface Processes and Ecological Conservation (Ministry of Education), Qinghai Normal University, Xining 810008, China
- National Positioning Observation and Research Station of Qinghai Lake Wetland Ecosystem in Qinghai, National Forestry and Grassland Administration, Haibei 812300, China
| | - Xia Wang
- Qinghai Province Key Laboratory of Physical Geography and Environmental Process, College of Geographical Science, Qinghai Normal University, Xining 810008, China; (N.Z.); (X.W.); (W.J.); (Z.Y.); (X.W.)
- Key Laboratory of Tibetan Plateau Land Surface Processes and Ecological Conservation (Ministry of Education), Qinghai Normal University, Xining 810008, China
- National Positioning Observation and Research Station of Qinghai Lake Wetland Ecosystem in Qinghai, National Forestry and Grassland Administration, Haibei 812300, China
| | - Junmin Li
- School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo 255000, China;
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Ning Z, Cai P, Zhang M. Metagenomic analysis revealed highly diverse carbon fixation microorganisms in a petroleum-hydrocarbon-contaminated aquifer. ENVIRONMENTAL RESEARCH 2024; 247:118289. [PMID: 38266905 DOI: 10.1016/j.envres.2024.118289] [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: 07/07/2023] [Revised: 12/23/2023] [Accepted: 01/20/2024] [Indexed: 01/26/2024]
Abstract
As one of the ultimate products of hydrocarbon biodegradation, inorganic carbon always be used to evaluate hydrocarbon biodegradation rates in petroleum-hydrocarbon-contaminated (PHC) aquifers. The evaluation method was challenged because of the existence of carbon fixation microorganisms, which may uptake inorganic carbons and consequently cause the biodegradation rates to be underestimated. We wonder if there are carbon fixation microorganisms in PHC aquifers. Although an extremely limited number of carbon fixation microorganisms in PHC sites have been studied in previous studies, the vast majority of microorganisms that participate in carbon fixation have not been systematically identified. To systematically reveal carbon fixation microorganisms and their survival environmental conditions, high-throughput metagenomic sequencing technologies, which are characterized by culture-independent, unbiased, and comprehensive methods for the detection and taxonomic characterization of microorganisms, were introduced to analyze the groundwater samples collected from a PHC aquifer. Results showed that 1041 genera were annotated as carbon fixation microorganisms, which accounted for 49% of the total number of genera in the PHC aquifer. Carbon fixation genes involved in Calvin-Benson-Bassham (CBB), 3-hydroxy propionate (3HP), reductive tricarboxylic acid (rTCA), and Wood-Ljungdahl (WL) cycles accounted for 2%, 41%, 34%, and 23% of the total carbon fixation genes, respectively, and 3HP, rTCA, and WL can be deemed as the dominant carbon fixation pathways. Most of the identified carbon fixation microorganisms are potential hydrocarbon biodegraders, and the most abundant carbon fixation microorganisms, such as Microbacterium, Novosphingobium, and Reyranella, were just the most abundant microorganisms in the aquifer system. It's deduced that most of the microorganisms in the aquifer were facultative autotrophic, and undertaking the dual responsibilities of degrading hydrocarbons to inorganic carbon and uptaking inorganic carbon to biomass.
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Affiliation(s)
- Zhuo Ning
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, China; Key Laboratory of Groundwater Remediation of Hebei Province & China Geological Survey, China.
| | - Pingping Cai
- School of Water Resources and Environment, Hebei GEO University, China.
| | - Min Zhang
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, China; Key Laboratory of Groundwater Remediation of Hebei Province & China Geological Survey, China.
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5
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Messer LF, Bourne DG, Robbins SJ, Clay M, Bell SC, McIlroy SJ, Tyson GW. A genome-centric view of the role of the Acropora kenti microbiome in coral health and resilience. Nat Commun 2024; 15:2902. [PMID: 38575584 PMCID: PMC10995205 DOI: 10.1038/s41467-024-46905-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 03/13/2024] [Indexed: 04/06/2024] Open
Abstract
Microbial diversity has been extensively explored in reef-building corals. However, the functional roles of coral-associated microorganisms remain poorly elucidated. Here, we recover 191 bacterial and 10 archaeal metagenome-assembled genomes (MAGs) from the coral Acropora kenti (formerly A. tenuis) and adjacent seawater, to identify microbial functions and metabolic interactions within the holobiont. We show that 82 MAGs were specific to the A. kenti holobiont, including members of the Pseudomonadota, Bacteroidota, and Desulfobacterota. A. kenti-specific MAGs displayed significant differences in their genomic features and functional potential relative to seawater-specific MAGs, with a higher prevalence of genes involved in host immune system evasion, nitrogen and carbon fixation, and synthesis of five essential B-vitamins. We find a diversity of A. kenti-specific MAGs encode the biosynthesis of essential amino acids, such as tryptophan, histidine, and lysine, which cannot be de novo synthesised by the host or Symbiodiniaceae. Across a water quality gradient spanning 2° of latitude, A. kenti microbial community composition is correlated to increased temperature and dissolved inorganic nitrogen, with corresponding enrichment in molecular chaperones, nitrate reductases, and a heat-shock protein. We reveal mechanisms of A. kenti-microbiome-symbiosis on the Great Barrier Reef, highlighting the interactions underpinning the health of this keystone holobiont.
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Affiliation(s)
- Lauren F Messer
- Centre for Microbiome Research, School of Biomedical Sciences, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, 4102, Australia.
- Division of Biological and Environmental Sciences, Faculty of Natural Sciences, University of Stirling, Stirling, FK9 4LA, Scotland, UK.
| | - David G Bourne
- College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia
- Australian Institute of Marine Science, Townsville, QLD, 4810, Australia
| | - Steven J Robbins
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Megan Clay
- Centre for Microbiome Research, School of Biomedical Sciences, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, 4102, Australia
| | - Sara C Bell
- College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia
- Australian Institute of Marine Science, Townsville, QLD, 4810, Australia
| | - Simon J McIlroy
- Centre for Microbiome Research, School of Biomedical Sciences, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, 4102, Australia
| | - Gene W Tyson
- Centre for Microbiome Research, School of Biomedical Sciences, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, 4102, Australia.
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6
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Hudson EP. The Calvin Benson cycle in bacteria: New insights from systems biology. Semin Cell Dev Biol 2024; 155:71-83. [PMID: 37002131 DOI: 10.1016/j.semcdb.2023.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 02/21/2023] [Accepted: 03/16/2023] [Indexed: 03/31/2023]
Abstract
The Calvin Benson cycle in phototrophic and chemolithoautotrophic bacteria has ecological and biotechnological importance, which has motivated study of its regulation. I review recent advances in our understanding of how the Calvin Benson cycle is regulated in bacteria and the technologies used to elucidate regulation and modify it, and highlight differences between and photoautotrophic and chemolithoautotrophic models. Systems biology studies have shown that in oxygenic phototrophic bacteria, Calvin Benson cycle enzymes are extensively regulated at post-transcriptional and post-translational levels, with multiple enzyme activities connected to cellular redox status through thioredoxin. In chemolithoautotrophic bacteria, regulation is primarily at the transcriptional level, with effector metabolites transducing cell status, though new methods should now allow facile, proteome-wide exploration of biochemical regulation in these models. A biotechnological objective is to enhance CO2 fixation in the cycle and partition that carbon to a product of interest. Flux control of CO2 fixation is distributed over multiple enzymes, and attempts to modulate gene Calvin cycle gene expression show a robust homeostatic regulation of growth rate, though the synthesis rates of products can be significantly increased. Therefore, de-regulation of cycle enzymes through protein engineering may be necessary to increase fluxes. Non-canonical Calvin Benson cycles, if implemented with synthetic biology, could have reduced energy demand and enzyme loading, thus increasing the attractiveness of these bacteria for industrial applications.
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Affiliation(s)
- Elton P Hudson
- Department of Protein Science, Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, Sweden.
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7
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Gao ZM, Xu T, Chen HG, Lu R, Tao J, Wang HB, Qiu JW, Wang Y. Early genome erosion and internal phage-symbiont-host interaction in the endosymbionts of a cold-seep tubeworm. iScience 2023; 26:107033. [PMID: 37389180 PMCID: PMC10300362 DOI: 10.1016/j.isci.2023.107033] [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: 11/30/2022] [Revised: 03/11/2023] [Accepted: 05/31/2023] [Indexed: 07/01/2023] Open
Abstract
Endosymbiosis with chemosynthetic Gammaproteobacteria is widely recognized as an adaptive mechanism of siboglinid tubeworms, yet evolution of these endosymbionts and their driving forces remain elusive. Here, we report a finished endosymbiont genome (HMS1) of the cold-seep tubeworm Sclerolinum annulatum. The HMS1 genome is small in size, with abundant prophages and transposable elements but lacking gene sets coding for denitrification, hydrogen oxidization, oxidative phosphorylation, vitamin biosynthesis, cell pH and/or sodium homeostasis, environmental sensing, and motility, indicative of early genome erosion and adaptive evolution toward obligate endosymbiosis. Unexpectedly, a prophage embedded in the HMS1 genome undergoes lytic cycle. Highly expressed ROS scavenger and LexA repressor genes indicate that the tubeworm host likely activates the lysogenic phage into lytic cycle through the SOS response to regulate endosymbiont population and harvest nutrients. Our findings indicate progressive evolution of Sclerolinum endosymbionts toward obligate endosymbiosis and expand the knowledge about phage-symbiont-host interaction in deep-sea tubeworms.
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Affiliation(s)
- Zhao-Ming Gao
- Institute of Deep Sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China
- HKUST-CAS Sanya Joint Laboratory of Marine Science Research, Chinese Academy of Sciences, Sanya 572000, China
| | - Ting Xu
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
| | - Hua-Guan Chen
- Institute of Deep Sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China
- University of Chinese Academy of Sciences, Beijing 101408, China
| | - Rui Lu
- Institute of Deep Sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China
- University of Chinese Academy of Sciences, Beijing 101408, China
| | - Jun Tao
- MLR Key Laboratory of Marine Mineral Resources, Guangzhou Marine Geological Survey, China Geological Survey, Guangzhou 511458, China
| | - Hong-Bin Wang
- MLR Key Laboratory of Marine Mineral Resources, Guangzhou Marine Geological Survey, China Geological Survey, Guangzhou 511458, China
| | - Jian-Wen Qiu
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Yong Wang
- Institute of Deep Sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China
- HKUST-CAS Sanya Joint Laboratory of Marine Science Research, Chinese Academy of Sciences, Sanya 572000, China
- Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518000, China
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8
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Chen Y, Dai T, Li N, Li Q, Lyu Y, Di P, Lyu L, Zhang S, Li J. Environmental heterogeneity shapes the C and S cycling-associated microbial community in Haima's cold seeps. Front Microbiol 2023; 14:1199853. [PMID: 37502402 PMCID: PMC10370420 DOI: 10.3389/fmicb.2023.1199853] [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: 04/04/2023] [Accepted: 06/07/2023] [Indexed: 07/29/2023] Open
Abstract
Environmental heterogeneity in cold seeps is usually reflected by different faunal aggregates. The sediment microbiome, especially the geochemical cycling-associated communities, sustains the ecosystem through chemosynthesis. To date, few studies have paid attention to the structuring and functioning of geochemical cycling-associated communities relating to environmental heterogeneity in different faunal aggregates of cold seeps. In this study, we profiled the microbial community of four faunal aggregates in the Haima cold seep, South China Sea. Through a combination of geochemical and meta-omics approaches, we have found that geochemical variables, such as sulfate and calcium, exhibited a significant variation between different aggregates, indicating changes in the methane flux. Anaerobic methanotrophic archaea (ANME), sulfate-reducing, and sulfide-oxidizing bacteria (SRB and SOB) dominated the microbial community but varied in composition among the four aggregates. The diversity of archaea and bacteria exhibited a strong correlation between sulfate, calcium, and silicate. Interspecies co-exclusion inferred by molecular ecological network analysis increased from non-seep to clam aggregates and peaked at the mussel aggregate. The networked geochemical cycling-associated species showed an obvious aggregate-specific distribution pattern. Notably, hydrocarbon oxidation and sulfate reduction by ANME and SRB produced carbonate and sulfide, driving the alkalization of the sediment environment, which may impact the microbial communities. Collectively, these results highlighted that geofluid and microbial metabolism together resulted in environmental heterogeneity, which shaped the C and S cycling-associated microbial community.
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Affiliation(s)
- Yu Chen
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong, China
| | - Tianjiao Dai
- School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing, China
| | - Niu Li
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong, China
| | - Qiqi Li
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong, China
| | - Yuanjiao Lyu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong, China
| | - Pengfei Di
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong, China
| | - Lina Lyu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong, China
| | - Si Zhang
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong, China
| | - Jie Li
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong, China
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9
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Prioretti L, D’Ermo G, Infossi P, Kpebe A, Lebrun R, Bauzan M, Lojou E, Guigliarelli B, Giudici-Orticoni MT, Guiral M. Carbon Fixation in the Chemolithoautotrophic Bacterium Aquifex aeolicus Involves Two Low-Potential Ferredoxins as Partners of the PFOR and OGOR Enzymes. Life (Basel) 2023; 13:life13030627. [PMID: 36983784 PMCID: PMC10052474 DOI: 10.3390/life13030627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/21/2023] [Accepted: 02/22/2023] [Indexed: 02/27/2023] Open
Abstract
Aquifex aeolicus is a microaerophilic hydrogen- and sulfur -oxidizing bacterium that assimilates CO2 via the reverse tricarboxylic acid cycle (rTCA). Key enzymes of this pathway are pyruvate:ferredoxin oxidoreductase (PFOR) and 2-oxoglutarate:ferredoxin oxidoreductase (OGOR), which are responsible, respectively, for the reductive carboxylation of acetyl-CoA to pyruvate and of succinyl-CoA to 2-oxoglutarate, two energetically unfavorable reactions that require a strong reduction potential. We have confirmed, by biochemistry and proteomics, that A. aeolicus possesses a pentameric version of these enzyme complexes ((αβγδε)2) and that they are highly abundant in the cell. In addition, we have purified and characterized, from the soluble fraction of A. aeolicus, two low redox potential and oxygen-stable [4Fe-4S] ferredoxins (Fd6 and Fd7, E0 = −440 and −460 mV, respectively) and shown that they can physically interact and exchange electrons with both PFOR and OGOR, suggesting that they could be the physiological electron donors of the system in vivo. Shotgun proteomics indicated that all the enzymes assumed to be involved in the rTCA cycle are produced in the A. aeolicus cells. A number of additional enzymes, previously suggested to be part of a putative partial Wood-Ljungdahl pathway used for the synthesis of serine and glycine from CO2 were identified by mass spectrometry, but their abundance in the cell seems to be much lower than that of the rTCA cycle. Their possible involvement in carbon assimilation is discussed.
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Affiliation(s)
- Laura Prioretti
- CNRS, Bioénergétique et Ingénierie des Protéines, Aix Marseille Université, IMM, 13009 Marseille, France
| | - Giulia D’Ermo
- CNRS, Bioénergétique et Ingénierie des Protéines, Aix Marseille Université, IMM, 13009 Marseille, France
| | - Pascale Infossi
- CNRS, Bioénergétique et Ingénierie des Protéines, Aix Marseille Université, IMM, 13009 Marseille, France
| | - Arlette Kpebe
- CNRS, Bioénergétique et Ingénierie des Protéines, Aix Marseille Université, IMM, 13009 Marseille, France
| | - Régine Lebrun
- CNRS, Aix Marseille Université, IMM, 13009 Marseille, France
| | - Marielle Bauzan
- CNRS, Aix Marseille Université, IMM, 13009 Marseille, France
| | - Elisabeth Lojou
- CNRS, Bioénergétique et Ingénierie des Protéines, Aix Marseille Université, IMM, 13009 Marseille, France
| | - Bruno Guigliarelli
- CNRS, Bioénergétique et Ingénierie des Protéines, Aix Marseille Université, IMM, 13009 Marseille, France
| | | | - Marianne Guiral
- CNRS, Bioénergétique et Ingénierie des Protéines, Aix Marseille Université, IMM, 13009 Marseille, France
- Correspondence:
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10
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Chen Y, Lyu Y, Zhang J, Li Q, Lyu L, Zhou Y, Kong J, Zeng X, Zhang S, Li J. Riddles of Lost City: Chemotrophic Prokaryotes Drives Carbon, Sulfur, and Nitrogen Cycling at an Extinct Cold Seep, South China Sea. Microbiol Spectr 2023; 11:e0333822. [PMID: 36511717 PMCID: PMC9927161 DOI: 10.1128/spectrum.03338-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 11/21/2022] [Indexed: 12/15/2022] Open
Abstract
Deep-sea cold seeps are one of the most productive ecosystems that sustained by hydrocarbons carried by the fluid. Once the seep fluid ceases, the thriving autotrophic communities die out, terming as the extinct seep. But heterotrophic fauna can still survive even for thousands of years. The critical role of prokaryotes in active seeps are well defined, but their functions in extinct seeps are poorly understood to date. Here, we clarified the diversity, taxonomic specificity, interspecies correlation, and metabolic profiles of sediment prokaryotes at an extinct seep site of Haima cold seep, South China Sea. Alpha diversity of archaea significantly increased, while that of bacteria remained unchanged in extinct seep compared to active seep. However, archaea composition did not differ significantly at extinct seep from active or nonseep sites based on weighted-unifrac dissimilarity, while bacteria composition exhibited significant difference. Distribution of archaea and bacteria showed clear specificity to extinct seeps, indicating the unique life strategies here. Prokaryotes might live chemolithoautotrophically on cycling of inorganic carbon, sulfur, and nitrogen, or chemoorganotrophically on recycling of hydrocarbons. Notably, many of the extinct seep specific species and networked keystone lineages are classified as Proteobacteria. Regarding the functional diversity and metabolic flexibility of this clade, Proteobacteria is supposed to integrate the geochemical cycles and play a critical role in energy and resource supplement for microbiome in extinct seep. Collectively, our findings shed lights on the microbial ecology and functional diversity in extinct seeps, providing new understanding of biogeochemical cycling after fluid cessation. IMPORTANCE This research paper uncovered the potential mechanisms for microbiota mediated geochemical cycling in extinct cold seep, advancing our understanding in deep sea microbiology ecology.
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Affiliation(s)
- Yu Chen
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, Guangdong, People’s Republic of China
| | - Yuanjiao Lyu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong, People’s Republic of China
| | - Jian Zhang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong, People’s Republic of China
| | - Qiqi Li
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong, People’s Republic of China
| | - Lina Lyu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong, People’s Republic of China
| | - Yingli Zhou
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, Guangdong, People’s Republic of China
| | - Jie Kong
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, Guangdong, People’s Republic of China
| | - Xinyang Zeng
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, Guangdong, People’s Republic of China
| | - Si Zhang
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, Guangdong, People’s Republic of China
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong, People’s Republic of China
| | - Jie Li
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, Guangdong, People’s Republic of China
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong, People’s Republic of China
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11
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Wei M, Zeng X, Han X, Shao Z, Xie Q, Dong C, Wang Y, Qiu Z. Potential autotrophic carbon-fixer and Fe(II)-oxidizer Alcanivorax sp. MM125-6 isolated from Wocan hydrothermal field. Front Microbiol 2022; 13:930601. [PMID: 36316996 PMCID: PMC9616709 DOI: 10.3389/fmicb.2022.930601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 09/09/2022] [Indexed: 12/02/2022] Open
Abstract
The genus Alcanivorax is common in various marine environments, including in hydrothermal fields. They were previously recognized as obligate hydrocarbonoclastic bacteria, but their potential for autotrophic carbon fixation and Fe(II)-oxidation remains largely elusive. In this study, an in situ enrichment experiment was performed using a hydrothermal massive sulfide slab deployed 300 m away from the Wocan hydrothermal vent. Furthermore, the biofilms on the surface of the slab were used as an inoculum, with hydrothermal massive sulfide powder from the same vent as an energy source, to enrich the potential iron oxidizer in the laboratory. Three dominant bacterial families, Alcanivoraceae, Pseudomonadaceae, and Rhizobiaceae, were enriched in the medium with hydrothermal massive sulfides. Subsequently, strain Alcanivorax sp. MM125-6 was isolated from the enrichment culture. It belongs to the genus Alcanivorax and is closely related to Alcanivorax profundimaris ST75FaO-1 T (98.9% sequence similarity) indicated by a phylogenetic analysis based on 16S rRNA gene sequences. Autotrophic growth experiments on strain MM125-6 revealed that the cell concentrations were increased from an initial 7.5 × 105 cells/ml to 3.13 × 108 cells/ml after 10 days, and that the δ13C VPDB in the cell biomass was also increased from 234.25‰ on day 2 to gradually 345.66 ‰ on day 10. The gradient tube incubation showed that bands of iron oxides and cells formed approximately 1 and 1.5 cm, respectively, below the air-agarose medium interface. In addition, the SEM-EDS data demonstrated that it can also secrete acidic exopolysaccharides and adhere to the surface of sulfide minerals to oxidize Fe(II) with NaHCO3 as the sole carbon source, which accelerates hydrothermal massive sulfide dissolution. These results support the conclusion that strain MM125-6 is capable of autotrophic carbon fixation and Fe(II) oxidization chemoautotrophically. This study expands our understanding of the metabolic versatility of the Alcanivorax genus as well as their important role(s) in coupling hydrothermal massive sulfide weathering and iron and carbon cycles in hydrothermal fields.
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Affiliation(s)
- Mingcong Wei
- Ocean College, Zhejiang University, Zhoushan, China
- Key Laboratory of Submarine Geosciences, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Xiang Zeng
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China
| | - Xiqiu Han
- Ocean College, Zhejiang University, Zhoushan, China
- Key Laboratory of Submarine Geosciences, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Zongze Shao
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China
| | - Qian Xie
- Key Laboratory of Submarine Geosciences, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
- School of Oceanography, Shanghai Jiao Tong University, Shanghai, China
| | - Chuanqi Dong
- Key Laboratory of Submarine Geosciences, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
- College of Marine Geosciences, Ocean University of China, Qingdao, China
| | - Yejian Wang
- Key Laboratory of Submarine Geosciences, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Zhongyan Qiu
- Key Laboratory of Submarine Geosciences, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
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12
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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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13
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Goswami P, He K, Li J, Pan Y, Roberts AP, Lin W. Magnetotactic bacteria and magnetofossils: ecology, evolution and environmental implications. NPJ Biofilms Microbiomes 2022; 8:43. [PMID: 35650214 PMCID: PMC9160268 DOI: 10.1038/s41522-022-00304-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Accepted: 05/04/2022] [Indexed: 11/08/2022] Open
Abstract
Magnetotactic bacteria (MTB) are a group of phylogenetically diverse and morphologically varied microorganisms with a magnetoresponsive capability called magnetotaxis or microbial magnetoreception. MTB are a distinctive constituent of the microbiome of aquatic ecosystems because they use Earth's magnetic field to align themselves in a north or south facing direction and efficiently navigate to their favored microenvironments. They have been identified worldwide from diverse aquatic and waterlogged microbiomes, including freshwater, saline, brackish and marine ecosystems, and some extreme environments. MTB play important roles in the biogeochemical cycling of iron, sulphur, phosphorus, carbon and nitrogen in nature and have been recognized from in vitro cultures to sequester heavy metals like selenium, cadmium, and tellurium, which makes them prospective candidate organisms for aquatic pollution bioremediation. The role of MTB in environmental systems is not limited to their lifespan; after death, fossil magnetosomal magnetic nanoparticles (known as magnetofossils) are a promising proxy for recording paleoenvironmental change and geomagnetic field history. Here, we summarize the ecology, evolution, and environmental function of MTB and the paleoenvironmental implications of magnetofossils in light of recent discoveries.
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Affiliation(s)
- Pranami Goswami
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, 100029, Beijing, China
- France-China Joint Laboratory for Evolution and Development of Magnetotactic Multicellular Organisms, Chinese Academy of Sciences, 100029, Beijing, China
- College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, 100049, Beijing, China
- Research School of Earth Sciences, Australian National University, ACT, Canberra, ACT, 2601, Australia
| | - Kuang He
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, 100029, Beijing, China
- France-China Joint Laboratory for Evolution and Development of Magnetotactic Multicellular Organisms, Chinese Academy of Sciences, 100029, Beijing, China
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Laboratory of Submarine Geosciences and Prospecting Techniques, MoE and College of Marine Geosciences, Ocean University of China, 266100, Qingdao, China
| | - Jinhua Li
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, 100029, Beijing, China
- France-China Joint Laboratory for Evolution and Development of Magnetotactic Multicellular Organisms, Chinese Academy of Sciences, 100029, Beijing, China
| | - Yongxin Pan
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, 100029, Beijing, China
- France-China Joint Laboratory for Evolution and Development of Magnetotactic Multicellular Organisms, Chinese Academy of Sciences, 100029, Beijing, China
- College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Andrew P Roberts
- Research School of Earth Sciences, Australian National University, ACT, Canberra, ACT, 2601, Australia.
| | - Wei Lin
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, 100029, Beijing, China.
- France-China Joint Laboratory for Evolution and Development of Magnetotactic Multicellular Organisms, Chinese Academy of Sciences, 100029, Beijing, China.
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Microbial Activities and Selection from Surface Ocean to Subseafloor on the Namibian Continental Shelf. Appl Environ Microbiol 2022; 88:e0021622. [PMID: 35404072 PMCID: PMC9088280 DOI: 10.1128/aem.00216-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Oxygen minimum zones (OMZs) are hot spots for redox-sensitive nitrogen transformations fueled by sinking organic matter. In comparison, the regulating role of sulfur-cycling microbes in marine OMZs, their impact on carbon cycling in pelagic and benthic habitats, and activities below the seafloor remain poorly understood. Using 13C DNA stable isotope probing (SIP) and metatranscriptomics, we explored microbial guilds involved in sulfur and carbon cycling from the ocean surface to the subseafloor on the Namibian shelf. There was a clear separation in microbial community structure across the seawater-seafloor boundary, which coincided with a 100-fold-increased concentration of microbial biomass and unique gene expression profiles of the benthic communities. 13C-labeled 16S rRNA genes in SIP experiments revealed carbon-assimilating taxa and their distribution across the sediment-water interface. Most of the transcriptionally active taxa among water column communities that assimilated 13C from diatom exopolysaccharides (mostly Bacteroidetes, Actinobacteria, Alphaproteobacteria, and Planctomycetes) also assimilated 13C-bicarbonate under anoxic conditions in sediment incubations. Moreover, many transcriptionally active taxa from the seafloor community (mostly sulfate-reducing Deltaproteobacteria and sulfide-oxidizing Gammaproteobacteria) that assimilated 13C-bicarbonate under sediment anoxic conditions also assimilated 13C from diatom exopolysaccharides in the surface ocean and OMZ waters. Despite strong selection at the sediment-water interface, many taxa related to either planktonic or benthic communities were found to be present at low abundance and actively assimilating carbon under both sediment and water column conditions. In austral winter, mixing of shelf waters reduces stratification and suspends sediments from the seafloor into the water column, potentially spreading metabolically versatile microbes across niches. IMPORTANCE Microbial activities in oxygen minimum zones (OMZs) transform inorganic fixed nitrogen into greenhouse gases, impacting the Earth’s climate and nutrient equilibrium. Coastal OMZs are predicted to expand with global change and increase carbon sedimentation to the seafloor. However, the role of sulfur-cycling microbes in assimilating carbon in marine OMZs and related seabed habitats remain poorly understood. Using 13C DNA stable isotope probing and metatranscriptomics, we explore microbial guilds involved in sulfur and carbon cycling from ocean surface to subseafloor on the Namibian shelf. Despite strong selection and differential activities across the sediment-water interface, many active taxa were identified in both planktonic and benthic communities, either fixing inorganic carbon or assimilating organic carbon from algal biomass. Our data show that many planktonic and benthic microbes linked to the sulfur cycle can cross redox boundaries when mixing of the shelf waters reduces stratification and suspends seafloor sediment particles into the water column.
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15
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Tian C, Wang H, Wu S, Bu C, Bai X, Li Y, Siddique KHM. Exogenous Microorganisms Promote Moss Biocrust Growth by Regulating the Microbial Metabolic Pathway in Artificial Laboratory Cultivation. Front Microbiol 2022; 13:819888. [PMID: 35308403 PMCID: PMC8924459 DOI: 10.3389/fmicb.2022.819888] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 02/07/2022] [Indexed: 01/24/2023] Open
Abstract
Moss-dominated biocrusts (moss crusts) are a feasible approach for the ecological restoration of drylands, but difficulty obtaining inoculum severely limits the progress of large-scale field applications. Exogenous microorganisms could improve moss growth and be conducive to moss inoculum propagation. In this study, we investigated the growth-promoting effects and potential mechanisms of exogenous microorganism additives on moss crusts. We used an incubator study to examine the effects of inoculation by heterotrophic microorganisms (Streptomyces pactum, Bacillus megaterium) and autotrophic microorganisms (Chlorella vulgaris, Microcoleus vaginatus) combined with Artemisia sphaerocephala gum on the growth of Bryum argenteum, the dominant moss crusts species in sandy deserts. Amplicon sequencing (16S and 18S rRNA) and PICRUSt2 were used to illustrate the microbial community structure and potential function in the optimal treatment at different developmental stages. Our results showed that exogenous microorganisms significantly promoted moss growth and increased aboveground biomass. After 30 days of cultivation, the Streptomyces pactum (1 g kg-1 substrate) + Chlorella vulgaris (3.33 L m-2) treatment presented optimal moss coverage, height, and density of 97.14%, 28.31 mm, and 2.28 g cm-2, respectively. The best-performing treatment had a higher relative abundance of Streptophyta-involved in moss growth-than the control. The control had significantly higher soil organic carbon than the best-performing treatment on day 30. Exogenous microorganisms improved eukaryotic community diversity and richness and may enhance soil microbial functional and metabolic diversity, such as growth and reproduction, carbon fixation, and cellulose and lignin decomposition, based on functional predictions. In summary, we identified the growth-promoting mechanisms of exogenous additives, providing a valuable reference for optimizing propagation technology for moss inoculum.
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Affiliation(s)
- Chang Tian
- Institute of Soil and Water Conservation, CAS and MWR, Yangling, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Heming Wang
- College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, China
| | - Shufang Wu
- College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, China
| | - Chongfeng Bu
- Institute of Soil and Water Conservation, CAS and MWR, Yangling, China
- Institute of Soil and Water Conservation, Northwest A&F University, Yangling, China
| | - Xueqiang Bai
- Institute of Soil and Water Conservation, Northwest A&F University, Yangling, China
| | - Yahong Li
- Institute of Soil and Water Conservation, Northwest A&F University, Yangling, China
| | - Kadambot H. M. Siddique
- The UWA Institute of Agriculture and School of Agriculture & Environment, The University of Western Australia, Perth, WA, Australia
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16
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Tang C, Yang F, Antonietti M. Carbon Materials Advancing Microorganisms in Driving Soil Organic Carbon Regulation. RESEARCH (WASHINGTON, D.C.) 2022; 2022:9857374. [PMID: 35098139 PMCID: PMC8777470 DOI: 10.34133/2022/9857374] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 12/10/2021] [Indexed: 12/20/2022]
Abstract
Carbon emission from soil is not only one of the major sources of greenhouse gases but also threatens biological diversity, agricultural productivity, and food security. Regulation and control of the soil carbon pool are political practices in many countries around the globe. Carbon pool management in engineering sense is much bigger and beyond laws and monitoring, as it has to contain proactive elements to restore active carbon. Biogeochemistry teaches us that soil microorganisms are crucial to manage the carbon content effectively. Adding carbon materials to soil is thereby not directly sequestration, as interaction of appropriately designed materials with the soil microbiome can result in both: metabolization and thereby nonsustainable use of the added carbon, or-more favorably-a biological amplification of human efforts and sequestration of extra CO2 by microbial growth. We review here potential approaches to govern soil carbon, with a special focus set on the emerging practice of adding manufactured carbon materials to control soil carbon and its biological dynamics. Notably, research on so-called "biochar" is already relatively mature, while the role of artificial humic substance (A-HS) in microbial carbon sequestration is still in the developing stage. However, it is shown that the preparation and application of A-HS are large biological levers, as they directly interact with the environment and community building of the biological soil system. We believe that A-HS can play a central role in stabilizing carbon pools in soil.
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Affiliation(s)
- Chunyu Tang
- School of Water Conservancy and Civil Engineering, Northeast Agricultural University, Harbin 150030, China
- Joint Laboratory of Northeast Agricultural University and Max Planck Institute of Colloids and Interfaces (NEAU-MPICI), Harbin 150030, China
| | - Fan Yang
- School of Water Conservancy and Civil Engineering, Northeast Agricultural University, Harbin 150030, China
- Joint Laboratory of Northeast Agricultural University and Max Planck Institute of Colloids and Interfaces (NEAU-MPICI), Harbin 150030, China
| | - Markus Antonietti
- Max Planck Institute of Colloids and Interfaces Department of Colloid Chemistry, 14476 Potsdam, Germany
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17
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Abel AJ, Hilzinger JM, Arkin AP, Clark DS. Systems-informed genome mining for electroautotrophic microbial production. Bioelectrochemistry 2022; 145:108054. [DOI: 10.1016/j.bioelechem.2022.108054] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 12/15/2021] [Accepted: 01/06/2022] [Indexed: 01/09/2023]
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18
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Abstract
Microbial communities associated with deep-sea animals are critical to the establishment of novel biological communities in unusual environments. Over the past few decades, rapid exploration of the deep sea has enabled the discovery of novel microbial communities, some of which form symbiotic relationships with animal hosts. Symbiosis in the deep sea changes host physiology, behavior, ecology, and evolution over time and space. Symbiont diversity within a host is often aligned with diverse metabolic pathways that broaden the environmental niche for the animal host. In this review, we focus on microbiomes and obligate symbionts found in different deep-sea habitats and how they facilitate survival of the organisms that live in these environments. In addition, we discuss factors that govern microbiome diversity, host specificity, and biogeography in the deep sea. Finally, we highlight the current limitations of microbiome research and draw a road map for future directions to advance our knowledge of microbiomes in the deep sea. Expected final online publication date for the Annual Review of Animal Biosciences, Volume 10 is February 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Eslam O Osman
- Biology Department, Eberly College, Pennsylvania State University, State College, Pennsylvania, USA; .,Red Sea Research Center (RSRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.,Marine Biology Lab, Zoology Department, Faculty of Science, Al-Azhar University, Cairo, Egypt
| | - Alexis M Weinnig
- Biology Department, Temple University, Philadelphia, Pennsylvania, USA
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Williams TJ, Allen MA, Berengut JF, Cavicchioli R. Shedding Light on Microbial "Dark Matter": Insights Into Novel Cloacimonadota and Omnitrophota From an Antarctic Lake. Front Microbiol 2021; 12:741077. [PMID: 34707591 PMCID: PMC8542988 DOI: 10.3389/fmicb.2021.741077] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 09/13/2021] [Indexed: 11/13/2022] Open
Abstract
The potential metabolism and ecological roles of many microbial taxa remain unknown because insufficient genomic data are available to assess their functional potential. Two such microbial "dark matter" taxa are the Candidatus bacterial phyla Cloacimonadota and Omnitrophota, both of which have been identified in global anoxic environments, including (but not limited to) organic-carbon-rich lakes. Using 24 metagenome-assembled genomes (MAGs) obtained from an Antarctic lake (Ace Lake, Vestfold Hills), novel lineages and novel metabolic traits were identified for both phyla. The Cloacimonadota MAGs exhibited a capacity for carbon fixation using the reverse tricarboxylic acid cycle driven by oxidation of hydrogen and sulfur. Certain Cloacimonadota MAGs encoded proteins that possess dockerin and cohesin domains, which is consistent with the assembly of extracellular cellulosome-like structures that are used for degradation of polypeptides and polysaccharides. The Omnitrophota MAGs represented phylogenetically diverse taxa that were predicted to possess a strong biosynthetic capacity for amino acids, nucleosides, fatty acids, and essential cofactors. All of the Omnitrophota were inferred to be obligate fermentative heterotrophs that utilize a relatively narrow range of organic compounds, have an incomplete tricarboxylic acid cycle, and possess a single hydrogenase gene important for achieving redox balance in the cell. We reason that both Cloacimonadota and Omnitrophota form metabolic interactions with hydrogen-consuming partners (methanogens and Desulfobacterota, respectively) and, therefore, occupy specific niches in Ace Lake.
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Affiliation(s)
- Timothy J Williams
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, NSW, Australia
| | - Michelle A Allen
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, NSW, Australia
| | - Jonathan F Berengut
- EMBL Australia Node for Single Molecule Science, School of Medical Sciences, UNSW Sydney, Kensington, NSW, Australia
| | - Ricardo Cavicchioli
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, NSW, Australia
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20
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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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21
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Chen YH, Chiang PW, Rogozin DY, Degermendzhy AG, Chiu HH, Tang SL. Salvaging high-quality genomes of microbial species from a meromictic lake using a hybrid sequencing approach. Commun Biol 2021; 4:996. [PMID: 34426638 PMCID: PMC8382752 DOI: 10.1038/s42003-021-02510-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 08/01/2021] [Indexed: 11/08/2022] Open
Abstract
Most of Earth's bacteria have yet to be cultivated. The metabolic and functional potentials of these uncultivated microorganisms thus remain mysterious, and the metagenome-assembled genome (MAG) approach is the most robust method for uncovering these potentials. However, MAGs discovered by conventional metagenomic assembly and binning are usually highly fragmented genomes with heterogeneous sequence contamination. In this study, we combined Illumina and Nanopore data to develop a new workflow to reconstruct 233 MAGs-six novel bacterial orders, 20 families, 66 genera, and 154 species-from Lake Shunet, a secluded meromictic lake in Siberia. With our workflow, the average N50 of reconstructed MAGs greatly increased 10-40-fold compared to when the conventional Illumina assembly and binning method were used. More importantly, six complete MAGs were recovered from our datasets. The recovery of 154 novel species MAGs from a rarely explored lake greatly expands the current bacterial genome encyclopedia.
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Affiliation(s)
- Yu-Hsiang Chen
- Bioinformatics Program, Taiwan International Graduate Program, National Taiwan University, Taipei, Taiwan
- Bioinformatics Program, Institute of Information Science, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Pei-Wen Chiang
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Denis Yu Rogozin
- Institute of Biophysics, Siberian Branch of Russian Academy of Sciences, Krasnoyarsk, Russia
- Siberian Federal University, Krasnoyarsk, Russia
| | - Andrey G Degermendzhy
- Institute of Biophysics, Siberian Branch of Russian Academy of Sciences, Krasnoyarsk, Russia
| | - Hsiu-Hui Chiu
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Sen-Lin Tang
- Bioinformatics Program, Institute of Information Science, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan.
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan.
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22
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Singh P, Jain KR, Shah V, Madamwar D. White Rann of Kachchh harbours distinct microbial diversity reflecting its unique biogeography. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 783:147094. [PMID: 34088141 DOI: 10.1016/j.scitotenv.2021.147094] [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: 01/13/2021] [Revised: 04/06/2021] [Accepted: 04/08/2021] [Indexed: 06/12/2023]
Abstract
The understanding of sub-surface soil microbial diversity is limited at both saline and hypersaline ecosystems, even though salinity is found to affect the microbial community in aqueous and terrestrial environment. In this study, a phylo-taxonomy analysis as well as the functional characteristics of microbial community of flat salt basin of White Rann of Kachchh (WR), Gujarat, India was performed along the natural salinity gradient. The high throughput sequencing approach has revealed the numerical abundance of bacteria relative to the archaea. Salinity, TOC, EC and sulphate concentration might be the primary driver of the community distribution along the transect at WR. The much anticipated effect of salinity gradient on the microbial composition surprisingly turned out to be more speculative, with little variance in the community composition along the spatial distance of WR. The metabolic pathways involved in energy metabolism (like carbon, nitrogen, sulphur) along with environmental adaptive genes (like osmotic and oxidative stress response, heat and cold shock genes clusters) were abundantly annotated from shot-gun metagenomic study. The carbonic anhydrase harbouring bacteria Bacillus sp. DM4CA1 was isolated from WR, having a catalytic ability for converting the gaseous carbon dioxide in presence of calcium carbonate into calcite at 25 % higher rate as compared to non-harbouring strains. The enzyme has a role in multiple alternative pathways in microbial metabolism. With the array of results obtained, the study could become the new reference for understanding the diversity structure and functional characteristics of the microbial community of terrestrial saline environment.
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Affiliation(s)
- Prachi Singh
- Post-Graduate Department of Biosciences, UGC Centre of Advanced Study, Sardar Patel University, Satellite Campus, Vadtal Road, Bakrol, 388 315 Anand, Gujarat, India.
| | - Kunal R Jain
- Post-Graduate Department of Biosciences, UGC Centre of Advanced Study, Sardar Patel University, Satellite Campus, Vadtal Road, Bakrol, 388 315 Anand, Gujarat, India
| | - Varun Shah
- School of Life Sciences, Faculty of Science, Atmiya University, Yogidham Gurukul, Kalawad Road, Rajkot 360 005, Gujarat, India; Aanvik LifeSciences Pvt. Ltd., Ahmedabad 380 013, Gujarat, India
| | - Datta Madamwar
- Post-Graduate Department of Biosciences, UGC Centre of Advanced Study, Sardar Patel University, Satellite Campus, Vadtal Road, Bakrol, 388 315 Anand, Gujarat, India; P.D. Patel Institute of Applied Sciences, Charotar University of Sciences and Technology (CHARUSAT), Changa 388 421, Gujarat, India.
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23
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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: 0.7] [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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24
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Sogin EM, Kleiner M, Borowski C, Gruber-Vodicka HR, Dubilier N. Life in the Dark: Phylogenetic and Physiological Diversity of Chemosynthetic Symbioses. Annu Rev Microbiol 2021; 75:695-718. [PMID: 34351792 DOI: 10.1146/annurev-micro-051021-123130] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Possibly the last discovery of a previously unknown major ecosystem on Earth was made just over half a century ago, when researchers found teaming communities of animals flourishing two and a half kilometers below the ocean surface at hydrothermal vents. We now know that these highly productive ecosystems are based on nutritional symbioses between chemosynthetic bacteria and eukaryotes and that these chemosymbioses are ubiquitous in both deep-sea and shallow-water environments. The symbionts are primary producers that gain energy from the oxidation of reduced compounds, such as sulfide and methane, to fix carbon dioxide or methane into biomass to feed their hosts. This review outlines how the symbiotic partners have adapted to living together. We first focus on the phylogenetic and metabolic diversity of these symbioses and then highlight selected research directions that could advance our understanding of the processes that shaped the evolutionary and ecological success of these associations. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- E Maggie Sogin
- Max Planck Institute for Marine Microbiology, 28359, Bremen, Germany; ,
| | - Manuel Kleiner
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina 27607, USA
| | - Christian Borowski
- Max Planck Institute for Marine Microbiology, 28359, Bremen, Germany; , .,MARUM-Center for Marine Environmental Sciences, University of Bremen, 28359, Bremen, Germany
| | | | - Nicole Dubilier
- Max Planck Institute for Marine Microbiology, 28359, Bremen, Germany; , .,MARUM-Center for Marine Environmental Sciences, University of Bremen, 28359, Bremen, Germany
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25
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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: 5] [Impact Index Per Article: 1.3] [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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26
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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: 4.4] [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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27
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Lannes R, Olsson-Francis K, Lopez P, Bapteste E. Carbon Fixation by Marine Ultrasmall Prokaryotes. Genome Biol Evol 2019; 11:1166-1177. [PMID: 30903144 PMCID: PMC6475129 DOI: 10.1093/gbe/evz050] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/04/2019] [Indexed: 12/12/2022] Open
Abstract
Autotrophic carbon fixation is a crucial process for sustaining life on Earth. To date, six pathways, the Calvin–Benson–Bassham cycle, the reductive tricarboxylic acid cycle, the 3-hydroxypropionate bi-cycle, the Wood–Ljungdahl pathway, the dicarboxylate/4-hydroxybutyrate cycle, and the 4-hydroxybutyrate cycle, have been described. Nano-organisms such as members of the Candidate Phyla Radiation (CPR) bacterial superphylum and the Diapherotrites, Parvarchaeota, Aenigmarchaeota, Nanoarchaeota, Nanohalorchaeota (DPANN) archaeal superphylum could deeply impact carbon cycling and carbon fixation in ways that are still to be determined. CPR and DPANN are ubiquitous in the environment but understudied; their gene contents are not exhaustively described; and their metabolisms are not yet fully understood. Here, the completeness of each of the above pathways was quantified and tested for the presence of all key enzymes in nano-organisms from across the World Ocean. The novel marine ultrasmall prokaryotes were demonstrated to collectively harbor the genes required for carbon fixation, in particular the “energetically efficient” dicarboxylate/4-hydroxybutyrate pathway and the 4-hydroxybutyrate pathway. This contrasted with the known carbon metabolic pathways associated with CPR members in aquifers, where they are described as degraders (Castelle CJ, et al. 2015. Genomic expansion of domain archaea highlights roles for organisms from new phyla in anaerobic carbon cycling. Curr Biol. 25(6):690–701; Castelle CJ, et al. 2018. Biosynthetic capacity, metabolic variety and unusual biology in the CPR and DPANN radiations. Nat Rev Microbiol. 16(10):629–645; Anantharaman K, et al. 2016. Thousands of microbial genomes shed light on interconnected biogeochemical processes in an aquifer system. Nat Commun. 7:13219.). Our findings suggest that nano-organisms have a broader contribution to carbon fixation and cycling than currently assumed. Furthermore, CPR and DPANN superphyla are possibly not the only nanosized prokaryotes; therefore, the discovery of new autotrophic marine nano-organisms by future single cell genomics is anticipated.
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Affiliation(s)
- Romain Lannes
- Sorbonne Université, Institut de Systématique, Evolution, Biodiversité (ISYEB), Sorbonne Université, CNRS, Museum National d'Histoire Naturelle, EPHE, Université des Antilles, Paris, France
| | - Karen Olsson-Francis
- School of Environment, Earth and Ecosystems, The Open University, Milton Keynes, United Kingdom
| | - Philippe Lopez
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Sorbonne Université, CNRS, Museum National d'Histoire Naturelle, EPHE, Université des Antilles, Paris, France
| | - Eric Bapteste
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Sorbonne Université, CNRS, Museum National d'Histoire Naturelle, EPHE, Université des Antilles, Paris, France
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28
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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: 3.4] [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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