1
|
Glud RN, Schauberger C. Element cycling and microbial life in the hadal realm. Trends Microbiol 2024:S0966-842X(24)00174-4. [PMID: 39084910 DOI: 10.1016/j.tim.2024.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Revised: 07/10/2024] [Accepted: 07/11/2024] [Indexed: 08/02/2024]
Abstract
Hadal trenches represent the deepest oceanic realm and were once considered to be deprived of life. However, trenches act as important depocenters for organic matter with highly elevated microbial activity. In this forum, we discuss the biogeochemistry of the hadal realm and its microbial communities thriving at extreme hydrostatic pressure.
Collapse
Affiliation(s)
- Ronnie N Glud
- HADAL and Nordcee, Department of Biology, University of Southern Denmark, Odense, Denmark; Danish Institute for Advanced Study (DIAS), University of Southern Denmark, Odense, Denmark; Department of Ocean and Environmental Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan.
| | - Clemens Schauberger
- HADAL and Nordcee, Department of Biology, University of Southern Denmark, Odense, Denmark
| |
Collapse
|
2
|
Xiao W, Xu Y, Canfield DE, Wenzhöfer F, Zhang C, Glud RN. Strong linkage between benthic oxygen uptake and bacterial tetraether lipids in deep-sea trench regions. Nat Commun 2024; 15:3439. [PMID: 38653759 DOI: 10.1038/s41467-024-47660-3] [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: 12/14/2023] [Accepted: 04/09/2024] [Indexed: 04/25/2024] Open
Abstract
Oxygen in marine sediments regulates many key biogeochemical processes, playing a crucial role in shaping Earth's climate and benthic ecosystems. In this context, branched glycerol dialkyl glycerol tetraethers (brGDGTs), essential biomarkers in paleoenvironmental research, exhibit an as-yet-unresolved association with sediment oxygen conditions. Here, we investigated brGDGTs in sediments from three deep-sea regions (4045 to 10,100 m water depth) dominated by three respective trench systems and integrated the results with in situ oxygen microprofile data. Our results demonstrate robust correlations between diffusive oxygen uptake (DOU) obtained from microprofiles and brGDGT methylation and isomerization degrees, indicating their primary production within sediments and their strong linkage with microbial diagenetic activity. We establish a quantitative relationship between the Isomerization and Methylation index of Branched Tetraethers (IMBT) and DOU, suggesting its potential validity across deep-sea environments. Increased brGDGT methylation and isomerization likely enhance the fitness of source organisms in deep-sea habitats. Our study positions brGDGTs as a promising tool for quantifying benthic DOU in deep-sea settings, where DOU is a key metric for assessing sedimentary organic carbon degradation and microbial activity.
Collapse
Affiliation(s)
- Wenjie Xiao
- Department of Biology, HADAL & Nordcee, University of Southern Denmark, 5230, Odense M, Denmark.
- Shanghai Frontiers Research Center of the Hadal Biosphere, College of Oceanography and Ecological Science, Shanghai Ocean University, 201306, Shanghai, China.
- Shenzhen Key Laboratory of Marine Archaea Geo-Omics, Department of Ocean Science and Engineering, Southern University of Science and Technology, 518055, Shenzhen, China.
| | - Yunping Xu
- Shanghai Frontiers Research Center of the Hadal Biosphere, College of Oceanography and Ecological Science, Shanghai Ocean University, 201306, Shanghai, China.
| | - Donald E Canfield
- Department of Biology, HADAL & Nordcee, University of Southern Denmark, 5230, Odense M, Denmark
- Danish Institute for Advanced Study (DIAS), University of Southern Denmark, 5230, Odense M, Denmark
| | - Frank Wenzhöfer
- Department of Biology, HADAL & Nordcee, University of Southern Denmark, 5230, Odense M, Denmark
- HGF-MPG Group for Deep Sea Ecology & Technology, Alfred Wegener Institute Helmholtz Centre for Polar- and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
- Max Planck Institute for Marine Microbiology, Celsiusstr 1, D-28359, Bremen, Germany
| | - Chuanlun Zhang
- Shenzhen Key Laboratory of Marine Archaea Geo-Omics, Department of Ocean Science and Engineering, Southern University of Science and Technology, 518055, Shenzhen, China
- Shanghai Sheshan National Geophysical Observatory, 201602, Shanghai, China
| | - Ronnie N Glud
- Department of Biology, HADAL & Nordcee, University of Southern Denmark, 5230, Odense M, Denmark.
- Shanghai Frontiers Research Center of the Hadal Biosphere, College of Oceanography and Ecological Science, Shanghai Ocean University, 201306, Shanghai, China.
- Danish Institute for Advanced Study (DIAS), University of Southern Denmark, 5230, Odense M, Denmark.
- Department of Ocean and Environmental Sciences, Tokyo University of Marine Science and Technology, 26 108-8477, Tokyo, Japan.
| |
Collapse
|
3
|
Zhao R, Jørgensen SL, Babbin AR. An abundant bacterial phylum with nitrite-oxidizing potential in oligotrophic marine sediments. Commun Biol 2024; 7:449. [PMID: 38605091 PMCID: PMC11009272 DOI: 10.1038/s42003-024-06136-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 04/02/2024] [Indexed: 04/13/2024] Open
Abstract
Nitrite-oxidizing bacteria (NOB) are important nitrifiers whose activity regulates the availability of nitrite and dictates the magnitude of nitrogen loss in ecosystems. In oxic marine sediments, ammonia-oxidizing archaea (AOA) and NOB together catalyze the oxidation of ammonium to nitrate, but the abundance ratios of AOA to canonical NOB in some cores are significantly higher than the theoretical ratio range predicted from physiological traits of AOA and NOB characterized under realistic ocean conditions, indicating that some NOBs are yet to be discovered. Here we report a bacterial phylum Candidatus Nitrosediminicolota, members of which are more abundant than canonical NOBs and are widespread across global oligotrophic sediments. Ca. Nitrosediminicolota members have the functional potential to oxidize nitrite, in addition to other accessory functions such as urea hydrolysis and thiosulfate reduction. While one recovered species (Ca. Nitrosediminicola aerophilus) is generally confined within the oxic zone, another (Ca. Nitrosediminicola anaerotolerans) additionally appears in anoxic sediments. Counting Ca. Nitrosediminicolota as a nitrite-oxidizer helps to resolve the apparent abundance imbalance between AOA and NOB in oxic marine sediments, and thus its activity may exert controls on the nitrite budget.
Collapse
Affiliation(s)
- Rui Zhao
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Steffen L Jørgensen
- Centre for Deep-Sea Research, Department of Earth Science, University of Bergen, Bergen, Norway
| | - Andrew R Babbin
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.
| |
Collapse
|
4
|
Yang N, Lv Y, Ji M, Wu S, Zhang Y. High hydrostatic pressure stimulates microbial nitrate reduction in hadal trench sediments under oxic conditions. Nat Commun 2024; 15:2473. [PMID: 38503798 PMCID: PMC10951307 DOI: 10.1038/s41467-024-46897-2] [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: 07/12/2023] [Accepted: 03/13/2024] [Indexed: 03/21/2024] Open
Abstract
Hadal trenches are extreme environments situated over 6000 m below sea surface, where enormous hydrostatic pressure affects the biochemical cycling of elements. Recent studies have indicated that hadal trenches may represent a previously overlooked source of fixed nitrogen loss; however, the mechanisms and role of hydrostatic pressure in this process are still being debated. To this end, we investigate the effects of hydrostatic pressure (0.1 to 115 MPa) on the chemical profile, microbial community structure and functions of surface sediments from the Mariana Trench using a Deep Ocean Experimental Simulator supplied with nitrate and oxygen. We observe enhanced denitrification activity at high hydrostatic pressure under oxic conditions, while the anaerobic ammonium oxidation - a previously recognized dominant nitrogen loss pathway - is not detected. Additionally, we further confirm the simultaneous occurrence of nitrate reduction and aerobic respiration using a metatranscriptomic dataset from in situ RNA-fixed sediments in the Mariana Trench. Taken together, our findings demonstrate that hydrostatic pressure can influence microbial contributions to nitrogen cycling and that the hadal trenches are a potential nitrogen loss hotspot. Knowledge of the influence of hydrostatic pressure on anaerobic processes in oxygenated surface sediments can greatly broaden our understanding of element cycling in hadal trenches.
Collapse
Affiliation(s)
- Na Yang
- School of Oceanography; Shanghai Key Laboratory of Polar Life and Environment Sciences; MOE Key Laboratory of Polar Ecosystem and Climate Change, Shanghai Jiao Tong University, Shanghai, China
| | - Yongxin Lv
- School of Oceanography; Shanghai Key Laboratory of Polar Life and Environment Sciences; MOE Key Laboratory of Polar Ecosystem and Climate Change, Shanghai Jiao Tong University, Shanghai, China
| | - Mukan Ji
- Center for Pan-third Pole Environment, Lanzhou University, Lanzhou, China
| | - Shiguo Wu
- Institute of Deep-sea Science and Engineering, Chinese Academy of Science, Sanya, China
| | - Yu Zhang
- School of Oceanography; Shanghai Key Laboratory of Polar Life and Environment Sciences; MOE Key Laboratory of Polar Ecosystem and Climate Change, Shanghai Jiao Tong University, Shanghai, China.
- Laboratory for Polar Science, Polar Research Institute of China, Ministry of Natural Resources, Shanghai, China.
- Yazhou Bay Institute of Deepsea Sci-Tech, Shanghai Jiao Tong University, Sanya, China.
| |
Collapse
|
5
|
Liu J, Li DW, He X, Liu R, Cheng H, Su C, Chen M, Wang Y, Zhao Z, Xu H, Cheng Z, Wang Z, Pedentchouk N, Lea-Smith DJ, Todd JD, Liu X, Zhao M, Zhang XH. A unique subseafloor microbiosphere in the Mariana Trench driven by episodic sedimentation. MARINE LIFE SCIENCE & TECHNOLOGY 2024; 6:168-181. [PMID: 38433963 PMCID: PMC10902237 DOI: 10.1007/s42995-023-00212-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 11/23/2023] [Indexed: 03/05/2024]
Abstract
Hadal trenches are characterized by enhanced and infrequent high-rate episodic sedimentation events that likely introduce not only labile organic carbon and key nutrients but also new microbes that significantly alter the subseafloor microbiosphere. Currently, the role of high-rate episodic sedimentation in controlling the composition of the hadal subseafloor microbiosphere is unknown. Here, analyses of carbon isotope composition in a ~ 750 cm long sediment core from the Challenger Deep revealed noncontinuous deposition, with anomalous 14C ages likely caused by seismically driven mass transport and the funneling effect of trench geomorphology. Microbial community composition and diverse enzyme activities in the upper ~ 27 cm differed from those at lower depths, probably due to sudden sediment deposition and differences in redox condition and organic matter availability. At lower depths, microbial population numbers, and composition remained relatively constant, except at some discrete depths with altered enzyme activity and microbial phyla abundance, possibly due to additional sudden sedimentation events of different magnitude. Evidence is provided of a unique role for high-rate episodic sedimentation events in controlling the subsurface microbiosphere in Earth's deepest ocean floor and highlight the need to perform thorough analysis over a large depth range to characterize hadal benthic populations. Such depositional processes are likely crucial in shaping deep-water geochemical environments and thereby the deep subseafloor biosphere. Supplementary Information The online version contains supplementary material available at 10.1007/s42995-023-00212-y.
Collapse
Affiliation(s)
- 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 and Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
| | - Da-Wei Li
- 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
| | - Xinxin He
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and College of Marine Life Sciences, Ocean University of China, Qingdao, 266003 China
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
| | - Ronghua Liu
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and College of Marine Life Sciences, Ocean University of China, Qingdao, 266003 China
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
| | - Haojin Cheng
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and College of Marine Life Sciences, Ocean University of China, Qingdao, 266003 China
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
| | - Chenglong Su
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100 China
| | - Mengna Chen
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100 China
| | - Yonghong Wang
- Key Lab of Submarine Geosciences and Prospecting Techniques, Ministry of Education/College of Marine Geosciences, Ocean University of China, Qingdao, 266100 China
| | - Zhongsheng Zhao
- Key Laboratory of Physical Oceanography, Ministry of Education/Research Vessel Centre, Ocean University of China, Qingdao, 266100 China
| | - Hanyue Xu
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100 China
| | - Zhangyu Cheng
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100 China
| | - Zicheng Wang
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100 China
| | - Nikolai Pedentchouk
- School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ UK
| | - David J. Lea-Smith
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ UK
| | - Jonathan D. Todd
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ UK
| | - Xiaoshou Liu
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and College of Marine Life Sciences, Ocean University of China, Qingdao, 266003 China
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
| | - Meixun Zhao
- 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
| | - 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 and Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
| |
Collapse
|
6
|
Sun C, Zhang S, Yang J, Zhou H, Cheng H, Chen Z, Yu L, Wang Y, Chen X. Discrepant assembly processes of prokaryotic communities between the abyssal and hadal sediments in Yap Trench. ENVIRONMENTAL RESEARCH 2024; 241:117602. [PMID: 37951379 DOI: 10.1016/j.envres.2023.117602] [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: 08/05/2023] [Revised: 10/17/2023] [Accepted: 11/03/2023] [Indexed: 11/14/2023]
Abstract
Abyssal and hadal sediments represent two of the most type ecosystems on Earth and have the potential interactions with geochemistry. However, little is known about the prokaryotic community assembly and the response of prokaryotic communities to metal(loid)s in trench sediments due to the lack of adequate and appropriate samples. In this study, a systematic investigation combined the assembly mechanisms and co-occurrence patterns of prokaryotic communities between the hadal and abyssal sediments across the Yap Trench. The results revealed that the hadal prokaryotes had less species diversity, but more abundant function than the abyssal prokaryotes. The prokaryotic communities in the abyssal sediments had more core taxa than the hadal sediments. Twenty-one biomarkers mostly affiliated with Nitrosopumilaceae were detected using Random-Forests machine learning algorithm. Furthermore, stochasticity was dominant in the prokaryotic community assembly processes of the Yap Trench sediments. Meanwhile, homogeneous selection (32.6%-52.9%) belonging to deterministic processes governed the prokaryotic community assembly in hadal sediments with increasing of sediment depth. In addition to total nitrogen and total organic carbon, more metal(loid)s were significantly correlated with the prokaryotic community in the hadal sediments than that in the abyssal sediments. The hadal prokaryotic communities was most positively related to bismuth (r = 0.31, p < 0.01), followed by calcium, chromium, cerium, potassium, plumbum, scandium, titanium, and vanadium. Finally, co-occurrence networks revealed two potential dominant prokaryotic modules in Yap Trench sediments covaried across oceanographic zonation. By contrast, the hadal network had relatively more complexity, more bacterial taxa, and more associations among prokaryotic taxa, relative to the abyssal network. This study reveals potentially metal variables and community assembly mechanisms of the prokaryotic community in abyssal and hadal sediments and provides a better understanding on the prokaryotic diversity and ecology in trench sediment ecosystems.
Collapse
Affiliation(s)
- Chongran Sun
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, China
| | - Shuangfei Zhang
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, China
| | - Jichao Yang
- College of Marine Science and Engineering, Shandong University of Science and Technology, Qingdao, 266590, Shandong, China
| | - Hongbo Zhou
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, China; Key Laboratory of Biometallurgy, Ministry of Education, Changsha, 410083, Hunan, China
| | - Haina Cheng
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, China; Key Laboratory of Biometallurgy, Ministry of Education, Changsha, 410083, Hunan, China
| | - Zhu Chen
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, China; Key Laboratory of Biometallurgy, Ministry of Education, Changsha, 410083, Hunan, China
| | - Libo Yu
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, Fujian, China
| | - Yuguang Wang
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, China; Key Laboratory of Biometallurgy, Ministry of Education, Changsha, 410083, Hunan, China.
| | - Xinhua Chen
- Key Laboratory of Marine Biotechnology of Fujian Province, Institute of Oceanology, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China.
| |
Collapse
|
7
|
Zhang RY, Wang YR, Liu RL, Rhee SK, Zhao GP, Quan ZX. Metagenomic characterization of a novel non-ammonia-oxidizing Thaumarchaeota from hadal sediment. MICROBIOME 2024; 12:7. [PMID: 38191433 PMCID: PMC10773090 DOI: 10.1186/s40168-023-01728-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Accepted: 11/20/2023] [Indexed: 01/10/2024]
Abstract
BACKGROUND The hadal sediment, found at an ocean depth of more than 6000 m, is geographically isolated and under extremely high hydrostatic pressure, resulting in a unique ecosystem. Thaumarchaeota are ubiquitous marine microorganisms predominantly present in hadal environments. While there have been several studies on Thaumarchaeota there, most of them have primarily focused on ammonia-oxidizing archaea (AOA). However, systematic metagenomic research specifically targeting heterotrophic non-AOA Thaumarchaeota is lacking. RESULTS In this study, we explored the metagenomes of Challenger Deep hadal sediment, focusing on the Thaumarchaeota. Functional analysis of sequence reads revealed the potential contribution of Thaumarchaeota to recalcitrant dissolved organic matter degradation. Metagenome assembly binned one new group of hadal sediment-specific and ubiquitously distributed non-AOA Thaumarchaeota, named Group-3.unk. Pathway reconstruction of this new type of Thaumarchaeota also supports heterotrophic characteristics of Group-3.unk, along with ABC transporters for the uptake of amino acids and carbohydrates and catabolic utilization of these substrates. This new clade of Thaumarchaeota also contains aerobic oxidation of carbon monoxide-related genes. Complete glyoxylate cycle is a distinctive feature of this clade in supplying intermediates of anabolic pathways. The pan-genomic and metabolic analyses of metagenome-assembled genomes belonging to Group-3.unk Thaumarchaeota have highlighted distinctions, including the dihydroxy phthalate decarboxylase gene associated with the degradation of aromatic compounds and the absence of genes related to the synthesis of some types of vitamins compared to AOA. Notably, Group-3.unk shares a common feature with deep ocean AOA, characterized by their high hydrostatic pressure resistance, potentially associated with the presence of V-type ATP and di-myo-inositol phosphate syntheses-related genes. The enrichment of organic matter in hadal sediments might be attributed to the high recruitment of sequence reads of the Group-3.unk clade of heterotrophic Thaumarchaeota in the trench sediment. Evolutionary and genetic dynamic analyses suggest that Group-3 non-AOA consists of mesophilic Thaumarchaeota organisms. These results indicate a potential role in the transition from non-AOA to AOA Thaumarchaeota and from thermophilic to mesophilic Thaumarchaeota, shedding light on recent evolutionary pathways. CONCLUSIONS One novel clade of heterotrophic non-AOA Thaumarchaeota was identified through metagenome analysis of sediments from Challenger Deep. Our study provides insight into the ecology and genomic characteristics of the new sub-group of heterotrophic non-AOA Thaumarchaeota, thereby extending the knowledge of the evolution of Thaumarchaeota. Video Abstract.
Collapse
Affiliation(s)
- Ru-Yi Zhang
- Fudan Microbiome Center, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Institute of Biodiversity Science and Institute of Eco-Chongming, School of Life Sciences, Fudan University, Shanghai, China
| | - Yan-Ren Wang
- Fudan Microbiome Center, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Institute of Biodiversity Science and Institute of Eco-Chongming, School of Life Sciences, Fudan University, Shanghai, China
| | - Ru-Long Liu
- Shanghai Engineering Research Center of Hadal Science and Technology, College of Marine Sciences, Shanghai Ocean University, Shanghai, China
| | - Sung-Keun Rhee
- Department of Microbiology, Chungbuk National University, Cheongju, Republic of Korea
| | - Guo-Ping Zhao
- Fudan Microbiome Center, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Institute of Biodiversity Science and Institute of Eco-Chongming, School of Life Sciences, Fudan University, Shanghai, China
| | - Zhe-Xue Quan
- Fudan Microbiome Center, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Institute of Biodiversity Science and Institute of Eco-Chongming, School of Life Sciences, Fudan University, Shanghai, China.
| |
Collapse
|
8
|
Schauberger C, Thamdrup B, Lemonnier C, Trouche B, Poulain J, Wincker P, Arnaud-Haond S, Glud RN, Maignien L. Metagenome-assembled genomes of deep-sea sediments: changes in microbial functional potential lag behind redox transitions. ISME COMMUNICATIONS 2024; 4:ycad005. [PMID: 38282644 PMCID: PMC10809760 DOI: 10.1093/ismeco/ycad005] [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: 11/08/2023] [Revised: 11/21/2023] [Accepted: 11/22/2023] [Indexed: 01/30/2024]
Abstract
Hadal sediments are hotspots of microbial activity in the deep sea and exhibit strong biogeochemical gradients. But although these gradients are widely assumed to exert selective forces on hadal microbial communities, the actual relationship between biogeochemistry, functional traits, and microbial community structure remains poorly understood. We tested whether the biogeochemical conditions in hadal sediments select for microbes based on their genomic capacity for respiration and carbohydrate utilization via a metagenomic analysis of over 153 samples from the Atacama Trench region (max. depth = 8085 m). The obtained 1357 non-redundant microbial genomes were affiliated with about one-third of all known microbial phyla, with more than half belonging to unknown genera. This indicated that the capability to withstand extreme hydrostatic pressure is a phylogenetically widespread trait and that hadal sediments are inhabited by diverse microbial lineages. Although community composition changed gradually over sediment depth, these changes were not driven by selection for respiratory or carbohydrate degradation capability in the oxic and nitrogenous zones, except in the case of anammox bacteria and nitrifying archaea. However, selection based on respiration and carbohydrate degradation capacity did structure the communities of the ferruginous zone, where aerobic and nitrogen respiring microbes declined exponentially (half-life = 125-419 years) and were replaced by subsurface communities. These results highlight a delayed response of microbial community composition to selective pressure imposed by redox zonation and indicated that gradual changes in microbial composition are shaped by the high-resilience and slow growth of microbes in the seafloor.
Collapse
Affiliation(s)
- Clemens Schauberger
- Hadal & Nordcee, Department of Biology, University of Southern Denmark, Campusvej 55, Odense M 5230, Denmark
| | - Bo Thamdrup
- Hadal & Nordcee, Department of Biology, University of Southern Denmark, Campusvej 55, Odense M 5230, Denmark
| | - Clarisse Lemonnier
- Microbiology of Extreme Environments Laboratory, CNRS, IFREMER, Univ Brest, F-29280 Plouzané, France
| | - Blandine Trouche
- Microbiology of Extreme Environments Laboratory, CNRS, IFREMER, Univ Brest, F-29280 Plouzané, France
| | - Julie Poulain
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS,University of Évry, Université Paris-Saclay, 91057 Evry, France
| | - Patrick Wincker
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS,University of Évry, Université Paris-Saclay, 91057 Evry, France
| | - Sophie Arnaud-Haond
- MARBEC, CNRS, IRD, Institut Français de Recherche pour L'Exploitation de la Mer, Univ Montpellier, 34200 Sète, France
| | - Ronnie N Glud
- Hadal & Nordcee, Department of Biology, University of Southern Denmark, Campusvej 55, Odense M 5230, Denmark
- Department of Ocean and Environmental Sciences, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan
| | - Lois Maignien
- Microbiology of Extreme Environments Laboratory, CNRS, IFREMER, Univ Brest, F-29280 Plouzané, France
| |
Collapse
|
9
|
Zhao R, Zhang IH, Jayakumar A, Ward BB, Babbin AR. Age, metabolisms, and potential origin of dominant anammox bacteria in the global oxygen-deficient zones. ISME COMMUNICATIONS 2024; 4:ycae060. [PMID: 38770059 PMCID: PMC11104535 DOI: 10.1093/ismeco/ycae060] [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: 04/11/2024] [Accepted: 04/19/2024] [Indexed: 05/22/2024]
Abstract
Anammox bacteria inhabiting oxygen-deficient zones (ODZs) are a major functional group mediating fixed nitrogen loss in the global ocean. However, many basic questions regarding the diversity, broad metabolisms, origin, and adaptive mechanisms of ODZ anammox bacteria remain unaddressed. Here we report two novel metagenome-assembled genomes of anammox bacteria affiliated with the Scalindua genus, which represent most, if not all, of the anammox bacteria in the global ODZs. Metagenomic read-recruiting and comparison with historical data show that they are ubiquitously present in all three major ODZs. Beyond the core anammox metabolism, both organisms contain cyanase, and the more dominant one encodes a urease, indicating most ODZ anammox bacteria can utilize cyanate and urea in addition to ammonium. Molecular clock analysis suggests that the evolutionary radiation of these bacteria into ODZs occurred no earlier than 310 million years ago, ~1 billion years after the emergence of the earliest modern-type ODZs. Different strains of the ODZ Scalindua species are also found in benthic sediments, and the first ODZ Scalindua is likely derived from the benthos. Compared to benthic strains of the same clade, ODZ Scalindua uniquely encodes genes for urea utilization but has lost genes related to growth arrest, flagellum synthesis, and chemotaxis, presumably for adaptation to thrive in the global ODZ waters. Our findings expand the known metabolisms and evolutionary history of the bacteria controlling the global nitrogen budget.
Collapse
Affiliation(s)
- Rui Zhao
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Irene H Zhang
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Amal Jayakumar
- Department of Geosciences, Princeton University, Princeton, NJ 08544, United States
| | - Bess B Ward
- Department of Geosciences, Princeton University, Princeton, NJ 08544, United States
| | - Andrew R Babbin
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| |
Collapse
|
10
|
Trouche B, Schauberger C, Bouderka F, Auguet JC, Belser C, Poulain J, Thamdrup B, Wincker P, Arnaud-Haond S, Glud RN, Maignien L. Distribution and genomic variation of ammonia-oxidizing archaea in abyssal and hadal surface sediments. ISME COMMUNICATIONS 2023; 3:133. [PMID: 38135695 PMCID: PMC10746724 DOI: 10.1038/s43705-023-00341-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 11/20/2023] [Accepted: 12/05/2023] [Indexed: 12/24/2023]
Abstract
Ammonia-oxidizing archaea of the phylum Thaumarchaeota play a central role in the biogeochemical cycling of nitrogen in benthic sediments, at the interface between pelagic and subsurface ecosystems. However, our understanding of their niche separation and of the processes controlling their population structure in hadal and abyssal surface sediments is still limited. Here, we reconstructed 47 AOA metagenome-assembled genomes (MAGs) from surface sediments of the Atacama and Kermadec trench systems. They formed deep-sea-specific groups within the family Nitrosopumilaceae and were assigned to six amoA gene-based clades. MAGs from different clades had distinct distribution patterns along oxygen-ammonium counter gradients in surface sediments. At the species level, MAGs thus seemed to form different ecotypes and follow deterministic niche-based distributions. In contrast, intraspecific population structure, defined by patterns of Single Nucleotide Variants (SNV), seemed to reflect more complex contributions of both deterministic and stochastic processes. Firstly, the bathymetric range had a strong effect on population structure, with distinct populations in abyssal plains and hadal trenches. Then, hadal populations were clearly separated by trench system, suggesting a strong isolation-by-topography effect, whereas abyssal populations were rather controlled by sediment depth or geographic distances, depending on the clade considered. Interestingly, genetic variability between samples was lowest in sediment layers where the mean MAG coverage was highest, highlighting the importance of selective pressure linked with each AOA clade's ecological niche. Overall, our results show that deep-sea AOA genome distributions seem to follow both deterministic and stochastic processes, depending on the genomic variability scale considered.
Collapse
Affiliation(s)
- Blandine Trouche
- Univ Brest, CNRS, Ifremer, UMR6197 Biologie et Ecologie des Ecosystèmes marins Profonds, F-29280, Plouzané, France.
- Hadal & Nordcee, Department of Biology, University of Southern Denmark, Odense, Denmark.
| | - Clemens Schauberger
- Hadal & Nordcee, Department of Biology, University of Southern Denmark, Odense, Denmark
| | - Feriel Bouderka
- Univ Brest, CNRS, Ifremer, UMR6197 Biologie et Ecologie des Ecosystèmes marins Profonds, F-29280, Plouzané, France
| | | | - Caroline Belser
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, University of Évry, Université Paris-Saclay, 91057, Evry, France
| | - Julie Poulain
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, University of Évry, Université Paris-Saclay, 91057, Evry, France
| | - Bo Thamdrup
- Hadal & Nordcee, Department of Biology, University of Southern Denmark, Odense, Denmark
| | - Patrick Wincker
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, University of Évry, Université Paris-Saclay, 91057, Evry, France
| | | | - Ronnie N Glud
- Hadal & Nordcee, Department of Biology, University of Southern Denmark, Odense, Denmark
- Department of Ocean and Environmental Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
- Danish Institute for Advanced Study (DIAS), University of Southern Denmark, Campusvej 55, 5230, Odense, Denmark
| | - Loïs Maignien
- Univ Brest, CNRS, Ifremer, UMR6197 Biologie et Ecologie des Ecosystèmes marins Profonds, F-29280, Plouzané, France.
- Marine Biological Laboratory, Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Woods Hole, MA, USA.
| |
Collapse
|
11
|
Sun J, Zhou H, Cheng H, Chen Z, Yang J, Wang Y, Jing C. Depth-Dependent Distribution of Prokaryotes in Sediments of the Manganese Crust on Nazimov Guyots of the Magellan Seamounts. MICROBIAL ECOLOGY 2023; 86:3027-3042. [PMID: 37792089 DOI: 10.1007/s00248-023-02305-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 09/04/2023] [Indexed: 10/05/2023]
Abstract
Deep ocean polymetallic nodules, rich in cobalt, nickel, and titanium which are commonly used in high-technology and biotechnology applications, are being eyed for green energy transition through deep-sea mining operations. Prokaryotic communities underneath polymetallic nodules could participate in deep-sea biogeochemical cycling, however, are not fully described. To address this gap, we collected sediment cores from Nazimov guyots, where polymetallic nodules exist, to explore the diversity and vertical distribution of prokaryotic communities. Our 16S rRNA amplicon sequencing data, quantitative PCR results, and phylogenetic beta diversity indices showed that prokaryotic diversity in the surficial layers (0-8 cm) was > 4-fold higher compared to deeper horizons (8-26 cm), while heterotrophs dominated in all sediment horizons. Proteobacteria was the most abundant taxon (32-82%) across all sediment depths, followed by Thaumarchaeota (4-37%), Firmicutes (2-18%), and Planctomycetes (1-6%). Depth was the key factor controlling prokaryotic distribution, while heavy metals (e.g., iron, copper, nickel, cobalt, zinc) can also influence significantly the downcore distribution of prokaryotic communities. Analyses of phylogenetic diversity showed that deterministic processes governing prokaryotic assembly in surficial layers, contrasting with stochastic influences in deep layers. This was further supported from the detection of a more complex prokaryotic co-occurrence network in the surficial layer which suggested more diverse prokaryotic communities existed in the surface vs. deeper sediments. This study expands current knowledge on the vertical distribution of benthic prokaryotic diversity in deep sea settings underneath polymetallic nodules, and the results reported might set a baseline for future mining decisions.
Collapse
Affiliation(s)
- Jianxing Sun
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, People's Republic of China
| | - Hongbo Zhou
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, People's Republic of China
- Key Laboratory of Biohydrometallurgy of Ministry of Education, Changsha, 410083, Hunan, People's Republic of China
| | - Haina Cheng
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, People's Republic of China
- Key Laboratory of Biohydrometallurgy of Ministry of Education, Changsha, 410083, Hunan, People's Republic of China
| | - Zhu Chen
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, People's Republic of China
- Key Laboratory of Biohydrometallurgy of Ministry of Education, Changsha, 410083, Hunan, People's Republic of China
| | - Jichao Yang
- College of Marine Science and Engineering, Shandong University of Science and Technology, Qingdao, 266590, Shandong, People's Republic of China
| | - Yuguang Wang
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, People's Republic of China.
- Key Laboratory of Biohydrometallurgy of Ministry of Education, Changsha, 410083, Hunan, People's Republic of China.
| | - Chunlei Jing
- National Deepsea Center, Ministry of Natural Resources, Qingdao, 266237, Shandong, People's Republic of China.
| |
Collapse
|
12
|
Schauberger C, Seki D, Cutts EM, Glud RN, Thamdrup B. Uniform selective pressures within redox zones drive gradual changes in microbial community composition in hadal sediments. Environ Microbiol 2023; 25:1594-1604. [PMID: 36999247 DOI: 10.1111/1462-2920.16377] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 03/19/2023] [Indexed: 04/01/2023]
Abstract
Microbial communities in marine sediments are highly diverse, yet the processes that give rise to this complexity are unclear. It has been proposed that benthic microbial communities must be continuously re-seeded from the water column because dispersal within the sediment is severely limited. Previous studies consistently report that the composition of the microbial community gradually changes with sediment depth. However, the relative contributions of the processes that underlie these compositional gradients have not been determined, and it is unknown whether microbial dispersal is indeed too slow to outpace burial. Here, we applied ecological statistical frameworks to 16S rRNA gene amplicon-based community composition data from Atacama Trench sediments to investigate the links between biogeochemistry, burial, and microbial community assembly processes. We confirm that dispersal limitation affects microbial communities and find that gradual changes in community composition are driven by selective pressures that change abruptly across the discrete boundaries between redox zones rather than along continuous biogeochemical gradients, while selective pressures are uniform within each zone. The gradual changes in community composition over centimetres of depth within a zone hence reflects a decades-long response to the abruptly changing selective pressures.
Collapse
Affiliation(s)
- Clemens Schauberger
- Hadal & Nordcee, Department of Biology, University of Southern Denmark, Odense, Denmark
| | - David Seki
- Centre for Microbiology and Environmental Systems Science, Department of Microbiology and Ecosystem Science, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Elise M Cutts
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Ronnie N Glud
- Hadal & Nordcee, Department of Biology, University of Southern Denmark, Odense, Denmark
- Department of Ocean and Environmental Sciences, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo, 108-8477, Japan
| | - Bo Thamdrup
- Hadal & Nordcee, Department of Biology, University of Southern Denmark, Odense, Denmark
| |
Collapse
|
13
|
Zhao R, Le Moine Bauer S, Babbin AR. " Candidatus Subterrananammoxibiaceae," a New Anammox Bacterial Family in Globally Distributed Marine and Terrestrial Subsurfaces. Appl Environ Microbiol 2023; 89:e0080023. [PMID: 37470485 PMCID: PMC10467342 DOI: 10.1128/aem.00800-23] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 06/29/2023] [Indexed: 07/21/2023] Open
Abstract
Bacteria specialized in anaerobic ammonium oxidation (anammox) are widespread in many anoxic habitats and form an important functional guild in the global nitrogen cycle by consuming bio-available nitrogen for energy rather than biomass production. Due to their slow growth rates, cultivation-independent approaches have been used to decipher their diversity across environments. However, their full diversity has not been well recognized. Here, we report a new family of putative anammox bacteria, "Candidatus Subterrananammoxibiaceae," existing in the globally distributed terrestrial and marine subsurface (groundwater and sediments of estuary, deep-sea, and hadal trenches). We recovered a high-quality metagenome-assembled genome of this family, tentatively named "Candidatus Subterrananammoxibius californiae," from a California groundwater site. The "Ca. Subterrananammoxibius californiae" genome not only contains genes for all essential components of anammox metabolism (e.g., hydrazine synthase, hydrazine oxidoreductase, nitrite reductase, and nitrite oxidoreductase) but also has the capacity for urea hydrolysis. In an Arctic ridge sediment core where redox zonation is well resolved, "Ca. Subterrananammoxibiaceae" is confined within the nitrate-ammonium transition zone where the anammox rate maximum occurs, providing environmental proof of the anammox activity of this new family. Phylogenetic analysis of nitrite oxidoreductase suggests that a horizontal transfer facilitated the spreading of the nitrite oxidation capacity between anammox bacteria (in the Planctomycetota phylum) and nitrite-oxidizing bacteria from Nitrospirota and Nitrospinota. By recognizing this new anammox family, we propose that all lineages within the "Ca. Brocadiales" order have anammox capacity. IMPORTANCE Microorganisms called anammox bacteria are efficient in removing bioavailable nitrogen from many natural and human-made environments. They exist in almost every anoxic habitat where both ammonium and nitrate/nitrite are present. However, only a few anammox bacteria have been cultured in laboratory settings, and their full phylogenetic diversity has not been recognized. Here, we present a new bacterial family whose members are present across both the terrestrial and marine subsurface. By reconstructing a high-quality genome from the groundwater environment, we demonstrate that this family has all critical enzymes of anammox metabolism and, notably, also urea utilization. This bacterium family in marine sediments is also preferably present in the niche where the anammox process occurs. These findings suggest that this novel family, named "Candidatus Subterrananammoxibiaceae," is an overlooked group of anammox bacteria, which should have impacts on nitrogen cycling in a range of environments.
Collapse
Affiliation(s)
- Rui Zhao
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Sven Le Moine Bauer
- Centre for Deep Sea Research, Department of Earth Science, University of Bergen, Bergen, Norway
| | - Andrew R. Babbin
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| |
Collapse
|
14
|
Zhou X, Lennon JT, Lu X, Ruan A. Anthropogenic activities mediate stratification and stability of microbial communities in freshwater sediments. MICROBIOME 2023; 11:191. [PMID: 37626433 PMCID: PMC10464086 DOI: 10.1186/s40168-023-01612-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Accepted: 07/04/2023] [Indexed: 08/27/2023]
Abstract
BACKGROUND Freshwater sediment microbes are crucial decomposers that play a key role in regulating biogeochemical cycles and greenhouse gas emissions. They often exhibit a highly ordered structure along depth profiles. This stratification not only reflects redox effects but also provides valuable insights into historical transitions, as sediments serve as important archives for tracing environmental history. The Anthropocene, a candidate geological epoch, has recently garnered significant attention. However, the human impact on sediment zonation under the cover of natural redox niches remains poorly understood. Dam construction stands as one of the most far-reaching anthropogenic modifications of aquatic ecosystems. Here we attempted to identify the ecological imprint of damming on freshwater sediment microbiome. RESULTS We conducted a year-round survey on the sediment profiles of Lake Chaohu, a large shallow lake in China. Through depth-discrete shotgun metagenomics, metataxonomics, and geophysiochemical analyses, we unveiled a unique prokaryotic hierarchy shaped by the interplay of redox regime and historical damming (labeled by the 137Cs peak in AD 1963). Dam-induced initial differentiation was further amplified by nitrogen and methane metabolism, forming an abrupt transition governing nitrate-methane metabolic interaction and gaseous methane sequestration depth. Using a random forest algorithm, we identified damming-sensitive taxa that possess distinctive metabolic strategies, including energy-saving mechanisms, unique motility behavior, and deep-environment preferences. Moreover, null model analysis showed that damming altered microbial community assembly, from a selection-oriented deterministic process above to a more stochastic, dispersal-limited one below. Temporal investigation unveiled the rapid transition zone as an ecotone, characterized by high species richness, low community stability, and emergent stochasticity. Path analysis revealed the observed emergent stochasticity primarily came from the high metabolic flexibility, which potentially contributed to both ecological and statistical neutralities. CONCLUSIONS We delineate a picture in which dam-induced modifications in nutrient availability and sedimentation rates impact microbial metabolic activities and generate great changes in the community structure, assembly, and stability of the freshwater sediment microbiome. These findings reflect profound ecological and biogeochemical ramifications of human-Earth system interactions and help re-examine the mainstream views on the formation of sediment microbial stratification. Video Abstract.
Collapse
Affiliation(s)
- Xiaotian Zhou
- The National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing, 210024, China
- College of Hydrology and Water Resources, Hohai University, Nanjing, 210024, China
| | - Jay T Lennon
- Department of Biology, Indiana University, Bloomington, IN, 47405, USA
| | - Xiang Lu
- The National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing, 210024, China
- College of Hydrology and Water Resources, Hohai University, Nanjing, 210024, China
| | - Aidong Ruan
- The National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing, 210024, China.
- College of Hydrology and Water Resources, Hohai University, Nanjing, 210024, China.
| |
Collapse
|
15
|
Gorrasi S, Franzetti A, Brandt A, Minzlaff U, Pasqualetti M, Fenice M. Insights into the prokaryotic communities of the abyssal-hadal benthic-boundary layer of the Kuril Kamchatka Trench. ENVIRONMENTAL MICROBIOME 2023; 18:67. [PMID: 37533108 PMCID: PMC10398949 DOI: 10.1186/s40793-023-00522-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 07/14/2023] [Indexed: 08/04/2023]
Abstract
BACKGROUND The Kuril-Kamchatka Trench (maximum depth 9604 m), located in the NW Pacific Ocean, is among the top seven deepest hadal trenches. The work aimed to investigate the unexplored abyssal-hadal prokaryotic communities of this fascinating, but underrated environment. RESULTS As for the bacterial communities, we found that Proteobacteria (56.1-74.5%), Bacteroidetes (6.5-19.1%), and Actinobacteria (0.9-16.1%) were the most represented bacterial phyla over all samples. Thaumarchaeota (52.9-91.1%) was the most abundant phylum in the archaeal communities. The archaeal diversity was highly represented by the ammonia-oxidizing Nitrosopumilus, and the potential hydrocarbon-degrading bacteria Acinetobacter, Zhongshania, and Colwellia were the main bacterial genera. The α-diversity analysis evidenced that both prokaryotic communities were characterized by low evenness, as indicated by the high Gini index values (> 0.9). The β-diversity analysis (Redundancy Analysis) indicated that, as expected, the depth significantly affected the structure of the prokaryotic communities. The co-occurrence network revealed seven prokaryotic groups that covaried across the abyssal-hadal zone of the Kuril-Kamchatka Trench. Among them, the main group included the most abundant archaeal and bacterial OTUs (Nitrosopumilus OTU A2 and OTU A1; Acinetobacter OTU B1), which were ubiquitous across the trench. CONCLUSIONS This manuscript represents the first attempt to characterize the prokaryotic communities of the KKT abyssal-hadal zone. Our results reveal that the most abundant prokaryotes harbored by the abyssal-hadal zone of Kuril-Kamchatka Trench were chemolithotrophic archaea and heterotrophic bacteria, which did not show a distinctive pattern distribution according to depth. In particular, Acinetobacter, Zhongshania, and Colwellia (potential hydrocarbon degraders) were the main bacterial genera, and Nitrosopumilus (ammonia oxidizer) was the dominant representative of the archaeal diversity.
Collapse
Affiliation(s)
- Susanna Gorrasi
- Laboratory of Microbiology, Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, 01100, Italy.
| | - Andrea Franzetti
- Laboratory of Microbiology, Department of Earth and Environmental Sciences, University of Milano-Bicocca, Milano, 20126, Italy
| | - Angelika Brandt
- Senckenberg Research Institute and Natural History Museum, 60325, Frankfurt am Main, Germany
- Institute of Ecology, Diversity and Evolution, Goethe University, 60438, Frankfurt am Main, Germany
| | - Ulrike Minzlaff
- Institute of Ecology, Diversity and Evolution, Goethe University, 60438, Frankfurt am Main, Germany
| | - Marcella Pasqualetti
- Laboratory of Ecology of Marine Fungi - CoNISMa, Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, 01100, Italy
| | - Massimiliano Fenice
- Laboratory of Microbiology, Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, 01100, Italy.
- Laboratory of Applied Marine Microbiology - CoNISMa, Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, 01100, Italy.
| |
Collapse
|
16
|
Wu J, Wang L, Du J, Liu Y, Hu L, Wei H, Fang J, Liu R. Biogeographic distribution, ecotype partitioning and controlling factors of Chloroflexi in the sediments of six hadal trenches of the Pacific Ocean. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 880:163323. [PMID: 37030385 DOI: 10.1016/j.scitotenv.2023.163323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 04/02/2023] [Accepted: 04/02/2023] [Indexed: 05/27/2023]
Abstract
The hadal trenches are "hot spots" for mineralization of organic matter in the deep ocean. Chloroflexi are one of the most dominant and active taxa in trench sediments, serving as important drivers of carbon cycles in hadal trenches. However, current understanding on hadal Chloroflexi is largely restricted to individual trench. This study systematically analyzed the diversity, biogeographic distribution, ecotype partitioning as well as environmental drivers of Chloroflexi in the sediments of hadal trenches, by reanalyzing 16S rRNA gene libraries of 372 samples from 6 trenches around the Pacific Ocean. The results showed that Chloroflexi averagely account for 10.10 % and up to 59.95 % of total microbial communities in the trench sediments. Positive correlations between relative abundance of Chloroflexi and depths down the vertical sediment profiles were observed in all of the sediment cores analyzed, suggesting the increasing significance of Chloroflexi in deeper sediment layers. Overall, trench sediment Chloroflexi were mainly composed of the classes Dehalococcidia, Anaerolineae and JG30-KF-CM66, and four orders i.e. SAR202, Anaerolineales, norank JG30-KF-CM66 and S085, were identified as core taxa that were dominant and prevalent in the hadal trench sediments. A total of 22 subclusters were identified within these core orders, and distinct patterns of ecotype partitioning related with depths down the vertical sediment profiles were observed, suggesting the great diversification of metabolic potentials and environment preference of different Chloroflexi lineages. The spatial distribution of hadal Chloroflexi were found to be significantly related with multiple environmental factors, while depths down the vertical sediment profiles explained the highest proportion of variations. These results provide valuable information for further exploring the roles of Chloroflexi in biogeochemical cycle of the hadal zone, and lay the foundation for understanding the adaptive mechanisms and evolutionary characteristics of microorganisms in hadal trenches.
Collapse
Affiliation(s)
- Jiaxin Wu
- Shanghai Engineering Research Center of Hadal Science and Technology, College of Marine Sciences, Shanghai Ocean University, Shanghai, China; National Engineering Research Center for Oceanic Fisheries, Shanghai Ocean University, Shanghai, China
| | - Li Wang
- Shanghai Engineering Research Center of Hadal Science and Technology, College of Marine Sciences, Shanghai Ocean University, Shanghai, China; National Engineering Research Center for Oceanic Fisheries, Shanghai Ocean University, Shanghai, China
| | - Jiangtao Du
- Shanghai Engineering Research Center of Hadal Science and Technology, College of Marine Sciences, Shanghai Ocean University, Shanghai, China; National Engineering Research Center for Oceanic Fisheries, Shanghai Ocean University, Shanghai, China
| | - Yuheng Liu
- Shanghai Engineering Research Center of Hadal Science and Technology, College of Marine Sciences, Shanghai Ocean University, Shanghai, China; National Engineering Research Center for Oceanic Fisheries, Shanghai Ocean University, Shanghai, China
| | - Lin Hu
- Shanghai Engineering Research Center of Hadal Science and Technology, College of Marine Sciences, Shanghai Ocean University, Shanghai, China; National Engineering Research Center for Oceanic Fisheries, Shanghai Ocean University, Shanghai, China
| | - Hui Wei
- Shanghai Engineering Research Center of Hadal Science and Technology, College of Marine Sciences, Shanghai Ocean University, Shanghai, China; National Engineering Research Center for Oceanic Fisheries, Shanghai Ocean University, Shanghai, China
| | - Jiasong Fang
- Shanghai Engineering Research Center of Hadal Science and Technology, College of Marine Sciences, Shanghai Ocean University, Shanghai, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China; Department of Natural Sciences, Hawaii Pacific University, Honolulu, HI, USA
| | - Rulong Liu
- Shanghai Engineering Research Center of Hadal Science and Technology, College of Marine Sciences, Shanghai Ocean University, Shanghai, China; National Engineering Research Center for Oceanic Fisheries, Shanghai Ocean University, Shanghai, China.
| |
Collapse
|
17
|
Zhao R, Babbin AR, Roerdink DL, Thorseth IH, Jørgensen SL. Nitrite accumulation and anammox bacterial niche partitioning in Arctic Mid-Ocean Ridge sediments. ISME COMMUNICATIONS 2023; 3:26. [PMID: 36991114 PMCID: PMC10060263 DOI: 10.1038/s43705-023-00230-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 02/27/2023] [Accepted: 03/13/2023] [Indexed: 03/30/2023]
Abstract
By consuming ammonium and nitrite, anammox bacteria form an important functional guild in nitrogen cycling in many environments, including marine sediments. However, their distribution and impact on the important substrate nitrite has not been well characterized. Here we combined biogeochemical, microbiological, and genomic approaches to study anammox bacteria and other nitrogen cycling groups in two sediment cores retrieved from the Arctic Mid-Ocean Ridge (AMOR). We observed nitrite accumulation in these cores, a phenomenon also recorded at 28 other marine sediment sites and in analogous aquatic environments. The nitrite maximum coincides with reduced abundance of anammox bacteria. Anammox bacterial abundances were at least one order of magnitude higher than those of nitrite reducers and the anammox abundance maxima were detected in the layers above and below the nitrite maximum. Nitrite accumulation in the two AMOR cores co-occurs with a niche partitioning between two anammox bacterial families (Candidatus Bathyanammoxibiaceae and Candidatus Scalinduaceae), likely dependent on ammonium availability. Through reconstructing and comparing the dominant anammox genomes (Ca. Bathyanammoxibius amoris and Ca. Scalindua sediminis), we revealed that Ca. B. amoris has fewer high-affinity ammonium transporters than Ca. S. sediminis and lacks the capacity to access alternative substrates and/or energy sources such as urea and cyanate. These features may restrict Ca. Bathyanammoxibiaceae to conditions of higher ammonium concentrations. These findings improve our understanding about nitrogen cycling in marine sediments by revealing coincident nitrite accumulation and niche partitioning of anammox bacteria.
Collapse
Affiliation(s)
- Rui Zhao
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
| | - Andrew R Babbin
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
| | - Desiree L Roerdink
- Centre for Deep Sea Research, Department of Earth Science, University of Bergen, Bergen, 5007, Norway
| | - Ingunn H Thorseth
- Centre for Deep Sea Research, Department of Earth Science, University of Bergen, Bergen, 5007, Norway
| | - Steffen L Jørgensen
- Centre for Deep Sea Research, Department of Earth Science, University of Bergen, Bergen, 5007, Norway.
| |
Collapse
|
18
|
Zhao R, Farag IF, Jørgensen SL, Biddle JF. Occurrence, Diversity, and Genomes of " Candidatus Patescibacteria" along the Early Diagenesis of Marine Sediments. Appl Environ Microbiol 2022; 88:e0140922. [PMID: 36468881 PMCID: PMC9765117 DOI: 10.1128/aem.01409-22] [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: 08/17/2022] [Accepted: 11/14/2022] [Indexed: 12/07/2022] Open
Abstract
The phylum "Candidatus Patescibacteria" (or Candidate Phyla Radiation [CPR]) accounts for roughly one-quarter of microbial diversity on Earth, but the presence and diversity of these bacteria in marine sediments have been rarely charted. Here, we investigate the abundance, diversity, and metabolic capacities of CPR bacteria in three sediment sites (Mohns Ridge, North Pond, and Costa Rica Margin) with samples covering a wide range of redox zones formed during the early diagenesis of organic matter. Through metagenome sequencing, we found that all investigated sediment horizons contain "Ca. Patescibacteria" (0.4 to 28% of the total communities), which are affiliated with the classes "Ca. Paceibacteria," "Ca. Gracilibacteria," "Ca. Microgenomatia," "Ca. Saccharimonadia," "Ca. ABY1," and "Ca. WWE3." However, only a subset of the diversity of marine sediment "Ca. Patescibacteria," especially the classes "Ca. Paceibacteria" and "Ca. Gracilibacteria," can be captured by 16S rRNA gene amplicon sequencing with commonly used universal primers. We recovered 11 metagenome-assembled genomes (MAGs) of CPR from these sediments, most of which are novel at the family or genus level in the "Ca. Paceibacteria" class and are missed by the amplicon sequencing. While individual MAGs are confined to specific anoxic niches, the lack of capacities to utilize the prevailing terminal electron acceptors indicates that they may not be directly selected by the local redox conditions. These CPR bacteria lack essential biosynthesis pathways and may use a truncated glycolysis pathway to conserve energy as fermentative organotrophs. Our findings suggest that marine sediments harbor some novel yet widespread CPR bacteria during the early diagenesis of organic matter, which needs to be considered in population dynamics assessments in this vast environment. IMPORTANCE Ultrasmall-celled "Ca. Patescibacteria" have been estimated to account for one-quarter of the total microbial diversity on Earth, the parasitic lifestyle of which may exert a profound control on the overall microbial population size of the local ecosystems. However, their diversity and metabolic functions in marine sediments, one of the largest yet understudied ecosystems on Earth, remain virtually uncharacterized. By applying cultivation-independent approaches to a range of sediment redox zones, we reveal that "Ca. Patescibacteria" members are rare but widespread regardless of the prevailing geochemical conditions. These bacteria are affiliated with novel branches of "Ca. Patescibacteria" and have been largely missed in marker gene-based surveys. They do not have respiration capacity but may conserve energy by fermenting organic compounds from their episymbiotic hosts. Our findings suggest that these novel "Ca. Patescibacteria" are among the previously overlooked microbes in diverse marine sediments.
Collapse
Affiliation(s)
- Rui Zhao
- School of Marine Science and Policy, University of Delaware, Lewes, Delaware, USA
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Ibrahim F. Farag
- School of Marine Science and Policy, University of Delaware, Lewes, Delaware, USA
| | - Steffen L. Jørgensen
- Centre for Deep Sea Research, Department of Earth Science, University of Bergen, Bergen, Norway
| | - Jennifer F. Biddle
- School of Marine Science and Policy, University of Delaware, Lewes, Delaware, USA
| |
Collapse
|
19
|
Coleine C, Delgado-Baquerizo M. Unearthing terrestrial extreme microbiomes for searching terrestrial-like life in the Solar System. Trends Microbiol 2022; 30:1101-1115. [PMID: 35568658 DOI: 10.1016/j.tim.2022.04.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 04/03/2022] [Accepted: 04/11/2022] [Indexed: 01/13/2023]
Abstract
The possibility of life elsewhere in the universe has fascinated humankind for ages. To the best of our knowledge, life, as we know it, is limited to planet Earth; yet current investigation suggests that life might be more common than previously thought. In this review, we explore extreme terrestrial analogue environments in the search for some notable examples of extreme organisms, including overlooked microbial groups such as viruses, fungi, and protists, associated with limits of life on Earth. This knowledge is integral to provide the foundational principles needed to predict what sort of Earth-like organisms we might find in the Solar System and beyond, and to understand the future and origins of life on Earth.
Collapse
Affiliation(s)
- Claudia Coleine
- Department of Ecological and Biological Sciences, University of Tuscia, 01100 Viterbo, Italy.
| | - Manuel Delgado-Baquerizo
- Laboratorio de Biodiversidad y Funcionamiento Ecosistémico. Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), CSIC, Av. Reina Mercedes 10, E-41012, Sevilla, Spain; Unidad Asociada CSIC-UPO (BioFun). Universidad Pablo de Olavide, 41013 Sevilla, Spain.
| |
Collapse
|
20
|
Møller TE, Le Moine Bauer S, Hannisdal B, Zhao R, Baumberger T, Roerdink DL, Dupuis A, Thorseth IH, Pedersen RB, Jørgensen SL. Mapping Microbial Abundance and Prevalence to Changing Oxygen Concentration in Deep-Sea Sediments Using Machine Learning and Differential Abundance. Front Microbiol 2022; 13:804575. [PMID: 35663876 PMCID: PMC9158483 DOI: 10.3389/fmicb.2022.804575] [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: 10/20/2021] [Accepted: 03/09/2022] [Indexed: 12/28/2022] Open
Abstract
Oxygen constitutes one of the strongest factors explaining microbial taxonomic variability in deep-sea sediments. However, deep-sea microbiome studies often lack the spatial resolution to study the oxygen gradient and transition zone beyond the oxic-anoxic dichotomy, thus leaving important questions regarding the microbial response to changing conditions unanswered. Here, we use machine learning and differential abundance analysis on 184 samples from 11 sediment cores retrieved along the Arctic Mid-Ocean Ridge to study how changing oxygen concentrations (1) are predicted by the relative abundance of higher taxa and (2) influence the distribution of individual Operational Taxonomic Units. We find that some of the most abundant classes of microorganisms can be used to classify samples according to oxygen concentration. At the level of Operational Taxonomic Units, however, representatives of common classes are not differentially abundant from high-oxic to low-oxic conditions. This weakened response to changing oxygen concentration suggests that the abundance and prevalence of highly abundant OTUs may be better explained by other variables than oxygen. Our results suggest that a relatively homogeneous microbiome is recruited to the benthos, and that the microbiome then becomes more heterogeneous as oxygen drops below 25 μM. Our analytical approach takes into account the oft-ignored compositional nature of relative abundance data, and provides a framework for extracting biologically meaningful associations from datasets spanning multiple sedimentary cores.
Collapse
Affiliation(s)
- Tor Einar Møller
- Department of Earth Science, University of Bergen, Bergen, Norway.,Centre for Deep Sea Research, University of Bergen, Bergen, Norway
| | - Sven Le Moine Bauer
- Department of Earth Science, University of Bergen, Bergen, Norway.,Centre for Deep Sea Research, University of Bergen, Bergen, Norway
| | - Bjarte Hannisdal
- Department of Earth Science, University of Bergen, Bergen, Norway.,Centre for Deep Sea Research, University of Bergen, Bergen, Norway.,Bjerknes Centre for Climate Research, University of Bergen, Bergen, Norway
| | - Rui Zhao
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Tamara Baumberger
- Cooperative Institute for Marine Ecosystem and Resources Studies, Oregon State University, Newport, OR, United States
| | - Desiree L Roerdink
- Department of Earth Science, University of Bergen, Bergen, Norway.,Centre for Deep Sea Research, University of Bergen, Bergen, Norway
| | | | - Ingunn H Thorseth
- Department of Earth Science, University of Bergen, Bergen, Norway.,Centre for Deep Sea Research, University of Bergen, Bergen, Norway
| | - Rolf Birger Pedersen
- Department of Earth Science, University of Bergen, Bergen, Norway.,Centre for Deep Sea Research, University of Bergen, Bergen, Norway
| | - Steffen Leth Jørgensen
- Department of Earth Science, University of Bergen, Bergen, Norway.,Centre for Deep Sea Research, University of Bergen, Bergen, Norway
| |
Collapse
|
21
|
Ma L, Jiang XT, Guan L, Li B, Zhang T. Nationwide biogeography and health implications of bacterial communities in household drinking water. WATER RESEARCH 2022; 215:118238. [PMID: 35278916 DOI: 10.1016/j.watres.2022.118238] [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: 03/23/2021] [Revised: 02/11/2022] [Accepted: 02/24/2022] [Indexed: 06/14/2023]
Abstract
Drinking water at the point of use harbors microorganisms that may pose potential risks to human health. However, the microbial diversity and health impacts of household drinking water are poorly understood, since culture-based methods only target on specific microorganisms and low biomass of drinking water hinders a high-throughput profiling. Here, we used an optimized workflow to efficiently collect microorganisms from low-biomass drinking water and performed deep sequencing of 16S rRNA genes to profile the bacterial diversity and biogeography of 110 household drinking water samples covering 38 cities of 29 provinces/regions in China, and further explored environmental drivers and potential health implications. Our analyses revealed a diverse drinking water community comprising a total of 22,771 operational taxonomic units (OTUs). The spatial turnover of drinking water communities is scale-dependent and appears to be driven largely by rainfall and water source river. The identified potential pathogenic species may have the possibility of causing health risks. Our novel insights enhance the current understanding of the diversity and biogeography of drinking water bacterial communities within a theoretical ecological framework and have further important implications for safe drinking water management and public health protection.
Collapse
Affiliation(s)
- Liping Ma
- School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China; Environmental Microbiome Engineering and Biotechnology Laboratory, Center for Environmental Engineering Research, Department of Civil Engineering, The University of Hong Kong, Hong Kong Special Administrative Region, China; Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, Shanghai, China
| | - Xiao-Tao Jiang
- Environmental Microbiome Engineering and Biotechnology Laboratory, Center for Environmental Engineering Research, Department of Civil Engineering, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Lei Guan
- School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China
| | - Bing Li
- Graduate School at Shenzhen, Tsinghua University, Shenzhen, China
| | - Tong Zhang
- Environmental Microbiome Engineering and Biotechnology Laboratory, Center for Environmental Engineering Research, Department of Civil Engineering, The University of Hong Kong, Hong Kong Special Administrative Region, China.
| |
Collapse
|
22
|
Microbiomes of Hadal Fishes across Trench Habitats Contain Similar Taxa and Known Piezophiles. mSphere 2022; 7:e0003222. [PMID: 35306867 PMCID: PMC9044967 DOI: 10.1128/msphere.00032-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Hadal snailfishes are the deepest-living fishes in the ocean, inhabiting trenches from depths of ∼6,000 to 8,000 m. While the microbial communities in trench environments have begun to be characterized, the microbes associated with hadal megafauna remain relatively unknown. Here, we describe the gut microbiomes of two hadal snailfishes, Pseudoliparis swirei (Mariana Trench) and Notoliparis kermadecensis (Kermadec Trench), using 16S rRNA gene amplicon sequencing. We contextualize these microbiomes with comparisons to the abyssal macrourid Coryphaenoides yaquinae and the continental shelf-dwelling snailfish Careproctus melanurus. The microbial communities of the hadal snailfishes were distinct from their shallower counterparts and were dominated by the same sequences related to the Mycoplasmataceae and Desulfovibrionaceae. These shared taxa indicate that symbiont lineages have remained similar to the ancestral symbiont since their geographic separation or that they are dispersed between geographically distant trenches and subsequently colonize specific hosts. The abyssal and hadal fishes contained sequences related to known, cultured piezophiles, microbes that grow optimally under high hydrostatic pressure, including Psychromonas, Moritella, and Shewanella. These taxa are adept at colonizing nutrient-rich environments present in the deep ocean, such as on particles and in the guts of hosts, and we hypothesize they could make a dietary contribution to deep-sea fishes by degrading chitin and producing fatty acids. We characterize the gut microbiota within some of the deepest fishes to provide new insight into the diversity and distribution of host-associated microbial taxa and the potential of these animals, and the microbes they harbor, for understanding adaptation to deep-sea habitats. IMPORTANCE Hadal trenches, characterized by high hydrostatic pressures and low temperatures, are one of the most extreme environments on our planet. By examining the microbiome of abyssal and hadal fishes, we provide insight into the diversity and distribution of host-associated life at great depth. Our findings show that there are similar microbial populations in fishes geographically separated by thousands of miles, reflecting strong selection for specific microbial lineages. Only a few psychropiezophilic taxa, which do not reflect the diversity of microbial life at great depth, have been successfully isolated in the laboratory. Our examination of deep-sea fish microbiomes shows that typical high-pressure culturing methodologies, which have largely remained unchanged since the pioneering work of Claude ZoBell in the 1950s, may simulate the chemical environment found in animal guts and helps explain why the same deep-sea genera are consistently isolated.
Collapse
|
23
|
Anammox bacteria drive fixed nitrogen loss in hadal trench sediments. Proc Natl Acad Sci U S A 2021; 118:2104529118. [PMID: 34764222 DOI: 10.1073/pnas.2104529118] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/30/2021] [Indexed: 01/04/2023] Open
Abstract
Benthic N2 production by microbial denitrification and anammox is the largest sink for fixed nitrogen in the oceans. Most N2 production occurs on the continental shelves, where a high flux of reactive organic matter fuels the depletion of nitrate close to the sediment surface. By contrast, N2 production rates in abyssal sediments are low due to low inputs of reactive organics, and nitrogen transformations are dominated by aerobic nitrification and the release of nitrate to the bottom water. Here, we demonstrate that this trend is reversed in the deepest parts of the oceans, the hadal trenches, where focusing of reactive organic matter enhances benthic microbial activity. Thus, at ∼8-km depth in the Atacama Trench, underlying productive surface waters, nitrate is depleted within a few centimeters of the sediment surface, N2 production rates reach those reported from some continental margin sites, and fixed nitrogen loss is mainly conveyed by anammox bacteria. These bacteria are closely related to those known from shallow oxygen minimum zone waters, and comparison of activities measured in the laboratory and in situ suggest they are piezotolerant. Even the Kermadec Trench, underlying oligotrophic surface waters, exhibits substantial fixed N removal. Our results underline the role of hadal sediments as hot spots of deep-sea biological activity, revealing a fully functional benthic nitrogen cycle at high hydrostatic pressure and pointing to hadal sediments as a previously unexplored niche for anaerobic microbial ecology and diagenesis.
Collapse
|