101
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Matsuura N, Masakke Y, Karthikeyan S, Kanazawa S, Honda R, Yamamoto-Ikemoto R, Konstantinidis KT. Metagenomic insights into the effect of sulfate on enhanced biological phosphorus removal. Appl Microbiol Biotechnol 2021; 105:2181-2193. [PMID: 33555362 DOI: 10.1007/s00253-021-11113-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 12/25/2020] [Accepted: 01/12/2021] [Indexed: 11/30/2022]
Abstract
Excess phosphorus in water supplies causes eutrophication, which degrades water quality. Hence, the efficient removal of phosphorus from wastewater represents a highly desirable process. Here, we evaluated the effect of sulfate concentration on enhanced biological phosphorus removal (EBPR), in which phosphorus is typically removed under anaerobic-oxic cycles, with sulfate reduction the predominant process in the anaerobic phase. Two sequencing batch EBPR reactors operated under high- (SBR-H) vs. low-sulfate (SBR-L) concentrations for 189 days and under three periods, i.e., start-up, sufficient acetate, and limited acetate. Under acetate-rich conditions, phosphorus removal efficiency was > 90% for both reactors; however, under acetate-limited conditions, only 34% and 91.3% of the phosphorus were removed for the SBR-L and the SBR-H, respectively. Metagenomic sequencing of the reactors showed that the relative abundance of the polyphosphate-accumulating and sulfur-reducing bacteria (SRB) was higher in the SBR-H, consistent with its higher phosphorus removal activity. Ten high-quality metagenome-assembled genomes, including one closely related to the genus Thiothrix disciformis (99.81% average amino acid identity), were recovered and predicted to simultaneously metabolize phosphorus and sulfur by the presence of phosphorus (ppk, ppx, pst, and pit) and sulfur (sul, sox, dsr, sqr, apr, cys, and sat) metabolism marker genes. The omics-based analysis provided a holistic view of the microbial ecosystem in the EBPR process and revealed that SRB and Thiothrix play key roles in the presence of high sulfate.Key points• We observed high phosphorus-removal efficiency in high-sulfate EBPR.• Metagenome-based analysis revealed sulfate-related metabolic mechanisms in EBPR.• SRB and PAOs showed interrelationships in the EBPR-sulfur systems.
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Affiliation(s)
- Norihisa Matsuura
- Faculty of Geosciences and Civil Engineering, Kanazawa University, Kanazawa, Ishikawa, Japan.
| | - Yalkhin Masakke
- Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Smruthi Karthikeyan
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Sui Kanazawa
- Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Ryo Honda
- Faculty of Geosciences and Civil Engineering, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Ryoko Yamamoto-Ikemoto
- Faculty of Geosciences and Civil Engineering, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Konstantinos T Konstantinidis
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, USA.,School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
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102
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Braccia DJ, Jiang X, Pop M, Hall AB. The Capacity to Produce Hydrogen Sulfide (H 2S) via Cysteine Degradation Is Ubiquitous in the Human Gut Microbiome. Front Microbiol 2021. [PMID: 34745023 DOI: 10.3389/fmicb.2021.705583/full] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/09/2023] Open
Abstract
As one of the three mammalian gasotransmitters, hydrogen sulfide (H2S) plays a major role in maintaining physiological homeostasis. Endogenously produced H2S plays numerous beneficial roles including mediating vasodilation and conferring neuroprotection. Due to its high membrane permeability, exogenously produced H2S originating from the gut microbiota can also influence human physiology and is implicated in reducing intestinal mucosal integrity and potentiating genotoxicity and is therefore a potential target for therapeutic interventions. Gut microbial H2S production is often attributed to dissimilatory sulfate reducers such as Desulfovibrio and Bilophila species. However, an alternative source for H2S production, cysteine degradation, is present in some gut microbes, but the genes responsible for cysteine degradation have not been systematically annotated in all known gut microbes. We classify mechanisms of cysteine degradation into primary, secondary, and erroneous levels of H2S production and perform a comprehensive search for primary, secondary, and erroneous cysteine-degrading enzymes in 4,644 non-redundant bacterial genomes from the Unified Human Gastrointestinal Genome (UHGG) catalog. Of the 4,644 genomes we have putatively identified 2,046 primary, 1,951 secondary, and 5 erroneous cysteine-degrading species. We identified the presence of at least one putative cysteine-degrading bacteria in metagenomic data of 100% of 6,623 healthy subjects and the expression of cysteine-degrading genes in metatranscriptomic data of 100% of 736 samples taken from 318 individuals. Additionally, putative cysteine-degrading bacteria are more abundant than sulfate-reducing bacteria across healthy controls, IBD patients and CRC patients (p < 2.2e-16, Wilcoxon rank sum test). Although we have linked many taxa with the potential for cysteine degradation, experimental validation is required to establish the H2S production potential of the gut microbiome. Overall, this study improves our understanding of the capacity for H2S production by the human gut microbiome and may help to inform interventions to therapeutically modulate gut microbial H2S production.
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Affiliation(s)
- Domenick J Braccia
- Center for Bioinformatics and Computational Biology, University of Maryland, College Park, College Park, MD, United States
| | - Xiaofang Jiang
- National Library of Medicine, National Institutes of Health, Bethesda, MD, United States
| | - Mihai Pop
- Center for Bioinformatics and Computational Biology, University of Maryland, College Park, College Park, MD, United States
- Department of Computer Science, University of Maryland, College Park, College Park, MD, United States
| | - A Brantley Hall
- Center for Bioinformatics and Computational Biology, University of Maryland, College Park, College Park, MD, United States
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, College Park, MD, United States
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103
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Yu X, Zhou J, Song W, Xu M, He Q, Peng Y, Tian Y, Wang C, Shu L, Wang S, Yan Q, Liu J, Tu Q, He Z. SCycDB: A curated functional gene database for metagenomic profiling of sulphur cycling pathways. Mol Ecol Resour 2020. [DOI: 10.1111/1755-0998.13306] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Xiaoli Yu
- Environmental Microbiomics Research Center School of Environmental Science and Engineering Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Sun Yat‐sen University Guangzhou China
| | - Jiayin Zhou
- Institute of Marine Science and Technology Shandong University Qingdao China
| | - Wen Song
- Institute of Marine Science and Technology Shandong University Qingdao China
| | - Mengzhao Xu
- Institute of Marine Science and Technology Shandong University Qingdao China
| | - Qiang He
- Department of Civil and Environmental Engineering The University of Tennessee Knoxville TN USA
| | - Yisheng Peng
- Environmental Microbiomics Research Center School of Environmental Science and Engineering Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Sun Yat‐sen University Guangzhou China
| | - Yun Tian
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems School of Life Sciences Xiamen University Xiamen China
| | - Cheng Wang
- Environmental Microbiomics Research Center School of Environmental Science and Engineering Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Sun Yat‐sen University Guangzhou China
| | - Longfei Shu
- Environmental Microbiomics Research Center School of Environmental Science and Engineering Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Sun Yat‐sen University Guangzhou China
| | - Shanquan Wang
- Environmental Microbiomics Research Center School of Environmental Science and Engineering Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Sun Yat‐sen University Guangzhou China
| | - Qingyun Yan
- Environmental Microbiomics Research Center School of Environmental Science and Engineering Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Sun Yat‐sen University Guangzhou China
| | - Jihua Liu
- Institute of Marine Science and Technology Shandong University Qingdao China
| | - Qichao Tu
- Institute of Marine Science and Technology Shandong University Qingdao China
| | - Zhili He
- Environmental Microbiomics Research Center School of Environmental Science and Engineering Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Sun Yat‐sen University Guangzhou China
- College of Agronomy Hunan Agricultural University Changsha China
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104
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Hong H, Li J, Wang Q, Lu H, Liu J, Dong YW, Zhang J, Li J, Williams MA, Huang B, Yan C. The legacy of trace metal deposition from historical anthropogenic river management: A regional driver of offshore sedimentary microbial diversity. JOURNAL OF HAZARDOUS MATERIALS 2020; 400:123164. [PMID: 32563906 DOI: 10.1016/j.jhazmat.2020.123164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 05/30/2020] [Accepted: 06/07/2020] [Indexed: 06/11/2023]
Abstract
River management, both modern and historical, have dramatically modified offshore environments. While numerous studies have described the modern impacts, very few have evaluated the legacies remaining from hundreds of years ago. Herein, we show trace metal enrichment in the surface sediment of the abandoned Yellow River Delta, hypothesized to be associated with ancient river management. Essentially, anthropogenic modification caused the river to shift, creating a 12.4×103 km2 area with elevated trace metals; characterized by clear metal deposition gradients. Geographical factors related to the ancient river mouth had the most significant influences on Zn (explained by distance to the river mouth, DTM) and Cd (DTM and sediment salinity), while the sediment absorptive capacity was associated with the reallocation of Cu (clay, silt, and iron), Ni (clay and iron), and Pb (silt and iron). Trace metal legacies showed stronger influences on prokaryotic diversity than on micro-eukaryotic diversity, with the former best described by changes in rare, rather than dominant families and classes, and explainable by an "overlapping micro-niche" model. The ancient river's legacies provide evidence of longer-term human disturbance over hundreds of years; as its impacts on associated benthic microbiomes have led to lessons for modern-day waterway management of benthic ecosystems.
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Affiliation(s)
- Hualong Hong
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, Xiamen 361102, Fujian, China; School of Plant and Environmental Sciences, Virginia Polytechnic Institute and State University, Blacksburg 24061, Virginia, USA.
| | - Junwei Li
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, Xiamen 361102, Fujian, China; Key Laboratory of the Ministry of Ecology of Rare and Endangered Species and Environmental Protection, Guangxi Normal University, Guilin 541004, Guangxi, China.
| | - Qiang Wang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, Xiamen 361102, Fujian, China.
| | - Haoliang Lu
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, Xiamen 361102, Fujian, China.
| | - Jingchun Liu
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, Xiamen 361102, Fujian, China.
| | - Yun-Wei Dong
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, Fujian, China.
| | - Jie Zhang
- Key Laboratory of Urban Environment Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, Fujian, China.
| | - Jian Li
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, Xiamen 361102, Fujian, China; School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, Jiangsu, China.
| | - Mark A Williams
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, Xiamen 361102, Fujian, China; School of Plant and Environmental Sciences, Virginia Polytechnic Institute and State University, Blacksburg 24061, Virginia, USA.
| | - Bangqin Huang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, Xiamen 361102, Fujian, China; State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, Fujian, China.
| | - Chongling Yan
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, Xiamen 361102, Fujian, China; State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, Fujian, China.
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105
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Vuillemin A, Kerrigan Z, D'Hondt S, Orsi WD. Exploring the abundance, metabolic potential and gene expression of subseafloor Chloroflexi in million-year-old oxic and anoxic abyssal clay. FEMS Microbiol Ecol 2020; 96:fiaa223. [PMID: 33150943 PMCID: PMC7688785 DOI: 10.1093/femsec/fiaa223] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 11/03/2020] [Indexed: 01/31/2023] Open
Abstract
Chloroflexi are widespread in subsurface environments, and recent studies indicate that they represent a major fraction of the communities in subseafloor sediment. Here, we compare the abundance, diversity, metabolic potential and gene expression of Chloroflexi from three abyssal sediment cores from the western North Atlantic Gyre (water depth >5400 m) covering up to 15 million years of sediment deposition, where Chloroflexi were found to represent major components of the community at all sites. Chloroflexi communities die off in oxic red clay over 10-15 million years, and gene expression was below detection. In contrast, Chloroflexi abundance and gene expression at the anoxic abyssal clay site increase below the seafloor and peak in 2-3 million-year-old sediment, indicating a comparably higher activity. Metatranscriptomes from the anoxic site reveal increased expression of Chloroflexi genes involved in cell wall biogenesis, protein turnover, inorganic ion transport, defense mechanisms and prophages. Phylogenetic analysis shows that these Chloroflexi are closely related to homoacetogenic subseafloor clades and actively transcribe genes involved in sugar fermentations, gluconeogenesis and Wood-Ljungdahl pathway in the subseafloor. Concomitant expression of cell division genes indicates that these putative homoacetogenic Chloroflexi are actively growing in these million-year-old anoxic abyssal sediments.
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Affiliation(s)
- Aurèle Vuillemin
- Department of Earth and Environmental Sciences, Paleontology & Geobiology, Ludwig-Maximilians-Universität München, Richard-Wagner-Strasse 10, 80333 Munich, Germany
| | - Zak Kerrigan
- Graduate School of Oceanography, University of Rhode Island, Narragansett Bay Campus, 215 South Ferry Road, Narragansett, RI 02882, USA
| | - Steven D'Hondt
- Graduate School of Oceanography, University of Rhode Island, Narragansett Bay Campus, 215 South Ferry Road, Narragansett, RI 02882, USA
| | - William D Orsi
- Department of Earth and Environmental Sciences, Paleontology & Geobiology, Ludwig-Maximilians-Universität München, Richard-Wagner-Strasse 10, 80333 Munich, Germany
- GeoBio-CenterLMU, Ludwig-Maximilians-Universität München, Richard-Wagner-Strasse 10, 80333 Munich, Germany
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106
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Waite DW, Chuvochina M, Pelikan C, Parks DH, Yilmaz P, Wagner M, Loy A, Naganuma T, Nakai R, Whitman WB, Hahn MW, Kuever J, Hugenholtz P. Proposal to reclassify the proteobacterial classes Deltaproteobacteria and Oligoflexia, and the phylum Thermodesulfobacteria into four phyla reflecting major functional capabilities. Int J Syst Evol Microbiol 2020; 70:5972-6016. [DOI: 10.1099/ijsem.0.004213] [Citation(s) in RCA: 696] [Impact Index Per Article: 174.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The class
Deltaproteobacteria
comprises an ecologically and metabolically diverse group of bacteria best known for dissimilatory sulphate reduction and predatory behaviour. Although this lineage is the fourth described class of the phylum
Proteobacteria
, it rarely affiliates with other proteobacterial classes and is frequently not recovered as a monophyletic unit in phylogenetic analyses. Indeed, one branch of the class
Deltaproteobacteria
encompassing Bdellovibrio-like predators was recently reclassified into a separate proteobacterial class, the
Oligoflexia
. Here we systematically explore the phylogeny of taxa currently assigned to these classes using 120 conserved single-copy marker genes as well as rRNA genes. The overwhelming majority of markers reject the inclusion of the classes
Deltaproteobacteria
and
Oligoflexia
in the phylum
Proteobacteria
. Instead, the great majority of currently recognized members of the class
Deltaproteobacteria
are better classified into four novel phylum-level lineages. We propose the names Desulfobacterota phyl. nov. and Myxococcota phyl. nov. for two of these phyla, based on the oldest validly published names in each lineage, and retain the placeholder name SAR324 for the third phylum pending formal description of type material. Members of the class
Oligoflexia
represent a separate phylum for which we propose the name Bdellovibrionota phyl. nov. based on priority in the literature and general recognition of the genus Bdellovibrio. Desulfobacterota phyl. nov. includes the taxa previously classified in the phylum
Thermodesulfobacteria
, and these reclassifications imply that the ability of sulphate reduction was vertically inherited in the
Thermodesulfobacteria
rather than laterally acquired as previously inferred. Our analysis also indicates the independent acquisition of predatory behaviour in the phyla Myxococcota and Bdellovibrionota, which is consistent with their distinct modes of action. This work represents a stable reclassification of one of the most taxonomically challenging areas of the bacterial tree and provides a robust framework for future ecological and systematic studies.
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Affiliation(s)
- David W Waite
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
| | - Maria Chuvochina
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
| | - Claus Pelikan
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Vienna, Austria
| | - Donovan H Parks
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
| | | | - Michael Wagner
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Vienna, Austria
| | - Alexander Loy
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Vienna, Austria
| | | | - Ryosuke Nakai
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Sapporo, Hokkaido, Japan
| | - William B Whitman
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
| | - Martin W Hahn
- Research Department for Limnology, University of Innsbruck, Mondsee, Austria
| | - Jan Kuever
- Department of Microbiology, Bremen Institute for Materials Testing, Bremen, Germany
| | - Philip Hugenholtz
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
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107
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Löffler M, Wallerang KB, Venceslau SS, Pereira IAC, Dahl C. The Iron-Sulfur Flavoprotein DsrL as NAD(P)H:Acceptor Oxidoreductase in Oxidative and Reductive Dissimilatory Sulfur Metabolism. Front Microbiol 2020; 11:578209. [PMID: 33178160 PMCID: PMC7596348 DOI: 10.3389/fmicb.2020.578209] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 09/23/2020] [Indexed: 11/13/2022] Open
Abstract
DsrAB-type dissimilatory sulfite reductase is a key enzyme of microbial sulfur-dependent energy metabolism. Sulfur oxidizers also contain DsrL, which is essential for sulfur oxidation in Allochromatium vinosum. This NAD(P)H oxidoreductase acts as physiological partner of oxidative-type rDsrAB. Recent analyses uncovered that DsrL is not confined to sulfur oxidizers but also occurs in (probable) sulfate/sulfur-reducing bacteria. Here, phylogenetic analysis revealed a separation into two major branches, DsrL-1, with two subgroups, and DsrL-2. When present in organisms with reductive-type DsrAB, DsrL is of type 2. In the majority of cases oxidative-type rDsrAB occurs with DsrL-1 but combination with DsrL-2-type enzymes is also observed. Three model DsrL proteins, DsrL-1A and DsrL-1B from the sulfur oxidizers A. vinosum and Chlorobaculum tepidum, respectively, as well as DsrL-2 from thiosulfate- and sulfur-reducing Desulfurella amilsii were kinetically characterized. DaDsrL-2 is active with NADP(H) but not with NAD(H) which we relate to a conserved YRR-motif in the substrate-binding domains of all DsrL-2 enzymes. In contrast, AvDsrL-1A has a strong preference for NAD(H) and the CtDsrL-1B enzyme is completely inactive with NADP(H). Thus, NAD+ as well as NADP+ are suitable in vivo electron acceptors for rDsrABL-1-catalyzed sulfur oxidation, while NADPH is required as electron donor for sulfite reduction. This observation can be related to the lower redox potential of the NADPH/NADP+ than the NADH/NAD+ couple under physiological conditions. Organisms with a rdsrAB and dsrL-1 gene combination can be confidently identified as sulfur oxidizers while predictions for organisms with other combinations require much more caution and additional information sources.
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Affiliation(s)
- Maria Löffler
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Kai B Wallerang
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Sofia S Venceslau
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Inês A C Pereira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Christiane Dahl
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
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108
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Wong HL, MacLeod FI, White RA, Visscher PT, Burns BP. Microbial dark matter filling the niche in hypersaline microbial mats. MICROBIOME 2020; 8:135. [PMID: 32938503 PMCID: PMC7495880 DOI: 10.1186/s40168-020-00910-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 08/19/2020] [Indexed: 05/08/2023]
Abstract
BACKGROUND Shark Bay, Australia, harbours one of the most extensive and diverse systems of living microbial mats that are proposed to be analogs of some of the earliest ecosystems on Earth. These ecosystems have been shown to possess a substantial abundance of uncultivable microorganisms. These enigmatic microbes, jointly coined as 'microbial dark matter' (MDM), are hypothesised to play key roles in modern microbial mats. RESULTS We reconstructed 115 metagenome-assembled genomes (MAGs) affiliated to MDM, spanning 42 phyla. This study reports for the first time novel microorganisms (Zixibacterial order GN15) putatively taking part in dissimilatory sulfate reduction in surface hypersaline settings, as well as novel eukaryote signature proteins in the Asgard archaea. Despite possessing reduced-size genomes, the MDM MAGs are capable of fermenting and degrading organic carbon, suggesting a role in recycling organic carbon. Several forms of RuBisCo were identified, allowing putative CO2 incorporation into nucleotide salvaging pathways, which may act as an alternative carbon and phosphorus source. High capacity of hydrogen production was found among Shark Bay MDM. Putative schizorhodopsins were also identified in Parcubacteria, Asgard archaea, DPANN archaea, and Bathyarchaeota, allowing these members to potentially capture light energy. Diversity-generating retroelements were prominent in DPANN archaea that likely facilitate the adaptation to a dynamic, host-dependent lifestyle. CONCLUSIONS This is the first study to reconstruct and describe in detail metagenome-assembled genomes (MAGs) affiliated with microbial dark matter in hypersaline microbial mats. Our data suggests that these microbial groups are major players in these systems. In light of our findings, we propose H2, ribose and CO/CO2 as the main energy currencies of the MDM community in these mat systems. Video Abstract.
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Affiliation(s)
- Hon Lun Wong
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, Australia
- Australian Centre for Astrobiology, University of New South Wales, Sydney, Australia
| | - Fraser I MacLeod
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, Australia
- Australian Centre for Astrobiology, University of New South Wales, Sydney, Australia
| | - Richard Allen White
- Australian Centre for Astrobiology, University of New South Wales, Sydney, Australia
- RAW Molecular Systems LLC, Spokane, WA, USA
- Department of Bioinformatics and Genomics, The University of North Carolina, Charlotte, NC, USA
| | - Pieter T Visscher
- Australian Centre for Astrobiology, University of New South Wales, Sydney, Australia
- Department of Marine Sciences, University of Connecticut, Mansfield, USA
- Biogeosciences, the Université de Bourgogne Franche-Comté, Dijon, France
| | - Brendan P Burns
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, Australia.
- Australian Centre for Astrobiology, University of New South Wales, Sydney, Australia.
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109
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Umezawa K, Kojima H, Kato Y, Fukui M. Disproportionation of inorganic sulfur compounds by a novel autotrophic bacterium belonging to Nitrospirota. Syst Appl Microbiol 2020; 43:126110. [DOI: 10.1016/j.syapm.2020.126110] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 06/23/2020] [Accepted: 06/25/2020] [Indexed: 12/21/2022]
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110
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Buongiorno J, Sipes K, Wasmund K, Loy A, Lloyd KG. Woeseiales transcriptional response to shallow burial in Arctic fjord surface sediment. PLoS One 2020; 15:e0234839. [PMID: 32853201 PMCID: PMC7451513 DOI: 10.1371/journal.pone.0234839] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 08/04/2020] [Indexed: 11/30/2022] Open
Abstract
Distinct lineages of Gammaproteobacteria clade Woeseiales are globally distributed in marine sediments, based on metagenomic and 16S rRNA gene analysis. Yet little is known about why they are dominant or their ecological role in Arctic fjord sediments, where glacial retreat is rapidly imposing change. This study combined 16S rRNA gene analysis, metagenome-assembled genomes (MAGs), and genome-resolved metatranscriptomics uncovered the in situ abundance and transcriptional activity of Woeseiales with burial in four shallow sediment sites of Kongsfjorden and Van Keulenfjorden of Svalbard (79°N). We present five novel Woeseiales MAGs and show transcriptional evidence for metabolic plasticity during burial, including sulfur oxidation with reverse dissimilatory sulfite reductase (dsrAB) down to 4 cm depth and nitrite reduction down to 6 cm depth. A single stress protein, spore protein SP21 (hspA), had a tenfold higher mRNA abundance than any other transcript, and was a hundredfold higher on average than other transcripts. At three out of the four sites, SP21 transcript abundance increased with depth, while total mRNA abundance and richness decreased, indicating a shift in investment from metabolism and other cellular processes to build-up of spore protein SP21. The SP21 gene in MAGs was often flanked by genes involved in membrane-associated stress response. The ability of Woeseiales to shift from sulfur oxidation to nitrite reduction with burial into marine sediments with decreasing access to overlying oxic bottom waters, as well as enter into a dormant state dominated by SP21, may account for its ubiquity and high abundance in marine sediments worldwide, including those of the rapidly shifting Arctic.
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Affiliation(s)
- Joy Buongiorno
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Katie Sipes
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Kenneth Wasmund
- Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
- Austrian Polar Research Institute, Vienna, Austria
| | - Alexander Loy
- Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
- Austrian Polar Research Institute, Vienna, Austria
| | - Karen G. Lloyd
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, United States of America
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111
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Chernyh NA, Neukirchen S, Frolov EN, Sousa FL, Miroshnichenko ML, Merkel AY, Pimenov NV, Sorokin DY, Ciordia S, Mena MC, Ferrer M, Golyshin PN, Lebedinsky AV, Cardoso Pereira IA, Bonch-Osmolovskaya EA. Dissimilatory sulfate reduction in the archaeon ‘Candidatus Vulcanisaeta moutnovskia’ sheds light on the evolution of sulfur metabolism. Nat Microbiol 2020; 5:1428-1438. [DOI: 10.1038/s41564-020-0776-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 07/16/2020] [Indexed: 02/07/2023]
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112
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Raggi L, García-Guevara F, Godoy-Lozano EE, Martínez-Santana A, Escobar-Zepeda A, Gutierrez-Rios RM, Loza A, Merino E, Sanchez-Flores A, Licea-Navarro A, Pardo-Lopez L, Segovia L, Juarez K. Metagenomic Profiling and Microbial Metabolic Potential of Perdido Fold Belt (NW) and Campeche Knolls (SE) in the Gulf of Mexico. Front Microbiol 2020; 11:1825. [PMID: 32903729 PMCID: PMC7438803 DOI: 10.3389/fmicb.2020.01825] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 07/10/2020] [Indexed: 01/04/2023] Open
Abstract
The Gulf of Mexico (GoM) is a particular environment that is continuously exposed to hydrocarbon compounds that may influence the microbial community composition. We carried out a metagenomic assessment of the bacterial community to get an overall view of this geographical zone. We analyzed both taxonomic and metabolic markers profiles to explain how the indigenous GoM microorganims participate in the biogeochemical cycling. Two geographically distant regions in the GoM, one in the north-west (NW) and one in the south-east (SE) of the GoM were analyzed and showed differences in their microbial composition and metabolic potential. These differences provide evidence the delicate equilibrium that sustains microbial communities and biogeochemical cycles. Based on the taxonomy and gene groups, the NW are more oxic sediments than SE ones, which have anaerobic conditions. Both water and sediments show the expected sulfur, nitrogen, and hydrocarbon metabolism genes, with particularly high diversity of the hydrocarbon-degrading ones. Accordingly, many of the assigned genera were associated with hydrocarbon degradation processes, Nitrospira and Sva0081 were the most abundant in sediments, while Vibrio, Alteromonas, and Alcanivorax were mostly detected in water samples. This basal-state analysis presents the GoM as a potential source of aerobic and anaerobic hydrocarbon degradation genes important for the ecological dynamics of hydrocarbons and the potential use for water and sediment bioremediation processes.
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Affiliation(s)
- Luciana Raggi
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
- CONACYT-Laboratorio de Biotecnología Acuícola, Instituto de Investigaciones Agropecuarias y Forestales, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Mexico
| | | | - E. Ernestina Godoy-Lozano
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
- Centro de Investigación Sobre Enfermedades Infecciosas, Departamento de Bioinformática en Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Mexico
| | | | | | | | - Antonio Loza
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Enrique Merino
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | | | - Alexei Licea-Navarro
- Laboratorio de Inmunología Molecular y Biotoxinas, Departamento de Innovación Biomedica, CICESE, Ensenada, Mexico
| | - Liliana Pardo-Lopez
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Lorenzo Segovia
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Katy Juarez
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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113
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Genome-Resolved Metagenomics and Detailed Geochemical Speciation Analyses Yield New Insights into Microbial Mercury Cycling in Geothermal Springs. Appl Environ Microbiol 2020; 86:AEM.00176-20. [PMID: 32414793 DOI: 10.1128/aem.00176-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 05/07/2020] [Indexed: 12/18/2022] Open
Abstract
Geothermal systems emit substantial amounts of aqueous, gaseous, and methylated mercury, but little is known about microbial influences on mercury speciation. Here, we report results from genome-resolved metagenomics and mercury speciation analysis of acidic warm springs in the Ngawha Geothermal Field (<55°C, pH <4.5), Northland Region, Aotearoa New Zealand. Our aim was to identify the microorganisms genetically equipped for mercury methylation, demethylation, or Hg(II) reduction to volatile Hg(0) in these springs. Dissolved total and methylated mercury concentrations in two adjacent springs with different mercury speciation ranked among the highest reported from natural sources (250 to 16,000 ng liter-1 and 0.5 to 13.9 ng liter-1, respectively). Total solid mercury concentrations in spring sediments ranged from 1,274 to 7,000 μg g-1 In the context of such ultrahigh mercury levels, the geothermal microbiome was unexpectedly diverse and dominated by acidophilic and mesophilic sulfur- and iron-cycling bacteria, mercury- and arsenic-resistant bacteria, and thermophilic and acidophilic archaea. By integrating microbiome structure and metagenomic potential with geochemical constraints, we constructed a conceptual model for biogeochemical mercury cycling in geothermal springs. The model includes abiotic and biotic controls on mercury speciation and illustrates how geothermal mercury cycling may couple to microbial community dynamics and sulfur and iron biogeochemistry.IMPORTANCE Little is currently known about biogeochemical mercury cycling in geothermal systems. The manuscript presents a new conceptual model, supported by genome-resolved metagenomic analysis and detailed geochemical measurements. The model illustrates environmental factors that influence mercury cycling in acidic springs, including transitions between solid (mineral) and aqueous phases of mercury, as well as the interconnections among mercury, sulfur, and iron cycles. This work provides a framework for studying natural geothermal mercury emissions globally. Specifically, our findings have implications for mercury speciation in wastewaters from geothermal power plants and the potential environmental impacts of microbially and abiotically formed mercury species, particularly where they are mobilized in spring waters that mix with surface or groundwaters. Furthermore, in the context of thermophilic origins for microbial mercury volatilization, this report yields new insights into how such processes may have evolved alongside microbial mercury methylation/demethylation and the environmental constraints imposed by the geochemistry and mineralogy of geothermal systems.
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Fernandez L, Peura S, Eiler A, Linz AM, McMahon KD, Bertilsson S. Diazotroph Genomes and Their Seasonal Dynamics in a Stratified Humic Bog Lake. Front Microbiol 2020; 11:1500. [PMID: 32714313 PMCID: PMC7341956 DOI: 10.3389/fmicb.2020.01500] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 06/09/2020] [Indexed: 12/28/2022] Open
Abstract
Aquatic N-fixation is generally associated with the growth and mass development of Cyanobacteria in nitrogen-deprived photic zones. However, sequenced genomes and environmental surveys suggest active aquatic N-fixation also by many non-cyanobacterial groups. Here, we revealed the seasonal variation and genomic diversity of potential N-fixers in a humic bog lake using metagenomic data and nif gene clusters analysis. Groups with diazotrophic operons were functionally divergent and included Cholorobi, Geobacter, Desulfobacterales, Methylococcales, and Acidobacteria. In addition to nifH (a gene that encodes the dinitrogenase reductase component of the molybdenum nitrogenase), we also identified sequences corresponding to vanadium and iron-only nitrogenase genes. Within the Chlorobi population, the nitrogenase (nifH) cluster was included in a well-structured retrotransposon. Furthermore, the presence of light-harvesting photosynthesis genes implies that anoxygenic photosynthesis may fuel nitrogen fixation under the prevailing low-irradiance conditions. The presence of rnf genes (related to the expression of H+/Na+-translocating ferredoxin: NAD+ oxidoreductase) in Methylococcales and Desulfobacterales suggests that other energy-generating processes may drive the costly N-fixation in the absence of photosynthesis. The highly reducing environment of the anoxic bottom layer of Trout Bog Lake may thus also provide a suitable niche for active N-fixers and primary producers. While future studies on the activity of these potential N-fixers are needed to clarify their role in freshwater nitrogen cycling, the metagenomic data presented here enabled an initial characterization of previously overlooked diazotrophs in freshwater biomes.
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Affiliation(s)
- Leyden Fernandez
- Department of Ecology and Genetics, Limnology and Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Sari Peura
- Department of Forest Mycology and Plant Pathology, Science for Life Laboratory, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Alexander Eiler
- Department of Ecology and Genetics, Limnology and Science for Life Laboratory, Uppsala University, Uppsala, Sweden
- Centre for Biogeochemistry in the Anthropocene, Department of Biosciences, Section for Aquatic Biology and Toxicology, University of Oslo, Oslo, Norway
| | - Alexandra M. Linz
- Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin–Madison, Madison, WI, United States
| | - Katherine D. McMahon
- Department of Bacteriology, University of Wisconsin–Madison, Madison, WI, United States
- Department of Civil and Environmental Engineering, University of Wisconsin–Madison, Madison, WI, United States
| | - Stefan Bertilsson
- Department of Ecology and Genetics, Limnology and Science for Life Laboratory, Uppsala University, Uppsala, Sweden
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden
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115
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Hou J, Sievert SM, Wang Y, Seewald JS, Natarajan VP, Wang F, Xiao X. Microbial succession during the transition from active to inactive stages of deep-sea hydrothermal vent sulfide chimneys. MICROBIOME 2020; 8:102. [PMID: 32605604 PMCID: PMC7329443 DOI: 10.1186/s40168-020-00851-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 04/28/2020] [Indexed: 05/19/2023]
Abstract
BACKGROUND Deep-sea hydrothermal vents are highly productive biodiversity hotspots in the deep ocean supported by chemosynthetic microorganisms. Prominent features of these systems are sulfide chimneys emanating high-temperature hydrothermal fluids. While several studies have investigated the microbial diversity in both active and inactive sulfide chimneys that have been extinct for up to thousands of years, little is known about chimneys that have ceased activity more recently, as well as the microbial succession occurring during the transition from active to inactive chimneys. RESULTS Genome-resolved metagenomics was applied to an active and a recently extinct (~ 7 years) sulfide chimney from the 9-10° N hydrothermal vent field on the East Pacific Rise. Full-length 16S rRNA gene and a total of 173 high-quality metagenome assembled genomes (MAGs) were retrieved for comparative analysis. In the active chimney (L-vent), sulfide- and/or hydrogen-oxidizing Campylobacteria and Aquificae with the potential for denitrification were identified as the dominant community members and primary producers, fixing carbon through the reductive tricarboxylic acid (rTCA) cycle. In contrast, the microbiome of the recently extinct chimney (M-vent) was largely composed of heterotrophs from various bacterial phyla, including Delta-/Beta-/Alphaproteobacteria and Bacteroidetes. Gammaproteobacteria were identified as the main primary producers, using the oxidation of metal sulfides and/or iron oxidation coupled to nitrate reduction to fix carbon through the Calvin-Benson-Bassham (CBB) cycle. Further analysis revealed a phylogenetically distinct Nitrospirae cluster that has the potential to oxidize sulfide minerals coupled to oxygen and/or nitrite reduction, as well as for sulfate reduction, and that might serve as an indicator for the early stages of chimneys after venting has ceased. CONCLUSIONS This study sheds light on the composition, metabolic functions, and succession of microbial communities inhabiting deep-sea hydrothermal vent sulfide chimneys. Collectively, microbial succession during the life span of a chimney could be described to proceed from a "fluid-shaped" microbial community in newly formed and actively venting chimneys supported by the oxidation of reductants in the hydrothermal fluid to a "mineral-shaped" community supported by the oxidation of minerals after hydrothermal activity has ceased. Remarkably, the transition appears to occur within the first few years, after which the communities stay stable for thousands of years. Video Abstract.
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Affiliation(s)
- Jialin Hou
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Stefan M Sievert
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Yinzhao Wang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Jeffrey S Seewald
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Vengadesh Perumal Natarajan
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Fengping Wang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
- School of Oceanography, Shanghai Jiao Tong University, Shanghai, China.
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, Guangdong, China.
| | - Xiang Xiao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, Guangdong, China.
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116
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Sandfeld T, Marzocchi U, Petro C, Schramm A, Risgaard-Petersen N. Electrogenic sulfide oxidation mediated by cable bacteria stimulates sulfate reduction in freshwater sediments. THE ISME JOURNAL 2020; 14:1233-1246. [PMID: 32042102 PMCID: PMC7174387 DOI: 10.1038/s41396-020-0607-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 01/27/2020] [Accepted: 01/30/2020] [Indexed: 11/08/2022]
Abstract
Cable bacteria are filamentous members of the Desulfobulbaceae family that oxidize sulfide with oxygen or nitrate by transferring electrons over centimeter distances in sediments. Recent studies show that freshwater sediments can support populations of cable bacteria at densities comparable to those found in marine environments. This is surprising since sulfide availability is presumably low in freshwater sediments due to sulfate limitation of sulfate reduction. Here we show that cable bacteria stimulate sulfate reduction in freshwater sediment through promotion of sulfate availability. Comparing experimental freshwater sediments with and without active cable bacteria, we observed a three- to tenfold increase in sulfate concentrations and a 4.5-fold increase in sulfate reduction rates when cable bacteria were present, while abundance and community composition of sulfate-reducing microorganisms (SRM) were unaffected. Correlation and ANCOVA analysis supported the hypothesis that the stimulation of sulfate reduction activity was due to relieve of the kinetic limitations of the SRM community through the elevated sulfate concentrations in sediments with cable bacteria activity. The elevated sulfate concentration was caused by cable bacteria-driven sulfide oxidation, by sulfate production from an indigenous sulfide pool, likely through cable bacteria-mediated dissolution and oxidation of iron sulfides, and by enhanced retention of sulfate, triggered by an electric field generated by the cable bacteria. Cable bacteria in freshwater sediments may thus be an integral component of a cryptic sulfur cycle and provide a mechanism for recycling of the scarce resource sulfate, stimulating sulfate reduction. It is possible that this stimulation has implication for methanogenesis and greenhouse gas emissions.
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Affiliation(s)
- Tobias Sandfeld
- Department of Bioscience, Section for Microbiology, Aarhus University, Aarhus, Denmark
- Center for Geomicrobiology, Aarhus University, Aarhus, Denmark
| | - Ugo Marzocchi
- Department of Bioscience, Section for Microbiology, Aarhus University, Aarhus, Denmark
- Center for Geomicrobiology, Aarhus University, Aarhus, Denmark
- Center for Electromicrobiology, Aarhus University, Aarhus, Denmark
- Department of Chemistry, Vrije Universiteit Brussel, Brussel, Belgium
| | - Caitlin Petro
- Department of Bioscience, Section for Microbiology, Aarhus University, Aarhus, Denmark
- Center for Geomicrobiology, Aarhus University, Aarhus, Denmark
- Center for Electromicrobiology, Aarhus University, Aarhus, Denmark
| | - Andreas Schramm
- Department of Bioscience, Section for Microbiology, Aarhus University, Aarhus, Denmark
- Center for Geomicrobiology, Aarhus University, Aarhus, Denmark
- Center for Electromicrobiology, Aarhus University, Aarhus, Denmark
| | - Nils Risgaard-Petersen
- Department of Bioscience, Section for Microbiology, Aarhus University, Aarhus, Denmark.
- Center for Geomicrobiology, Aarhus University, Aarhus, Denmark.
- Center for Electromicrobiology, Aarhus University, Aarhus, Denmark.
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117
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Neubeck A, Freund F. Sulfur Chemistry May Have Paved the Way for Evolution of Antioxidants. ASTROBIOLOGY 2020; 20:670-675. [PMID: 31880469 PMCID: PMC7232690 DOI: 10.1089/ast.2019.2156] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The first organisms on the young Earth, just 1-1.5 billion years old, were likely chemolithoautotrophic anaerobes, thriving in an anoxic world rich in water, CO2, and N2. It is generally assumed that, until the accumulation of O2 in the atmosphere, life was exempted from the oxidative stress that reactive oxygen species (ROS) impose on hydrocarbon-based life. Therefore, it is perplexing to note that life on the early Earth already carried antioxidants such as superoxide dismutase enzymes, catalase, and peroxiredoxins, the function of which is to counteract all forms of ROS, including H2O2. Phylogenetic investigations suggest that the presence of these enzymes in the last universal common ancestor, far predating the great oxygenation event (GOE) sometime between 2.3 and 2.7 billion years ago, is thought to be due to the appearance of oxygen-producing microorganisms and the subsequent need to respond to the appearance of ROS. Since the metabolic enzymes that counteract ROS have been found in all domains of life, they are considered of primitive origin. Two questions arise: (1) Could there be a nonbiological source of ROS that predates the oxygenic microbial activity? (2) Could sulfur, the homologue of oxygen, have played that role? Reactive sulfur species (RSS) may have triggered the evolution of antioxidants such that the ROS antioxidants started out as "antisulfur" enzymes developed to cope with, and take advantage of, various forms of RSS that were abundantly present on the early Earth.
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Affiliation(s)
- Anna Neubeck
- Department of Palaeobiology, Uppsala University, Uppsala, Sweden
- Address correspondence to: Anna Neubeck, Department of Palaeobiology, Uppsala University, Geocentrum, Villavägen 16, SE-752 36 Uppsala, Sweden
| | - Friedemann Freund
- Space Biosciences Research (Code SCR), NASA Ames Research Center, Mountain View, California
- SETI Institute, Carl Sagan Center, Mountain View, California
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118
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Colman DR, Lindsay MR, Amenabar MJ, Fernandes-Martins MC, Roden ER, Boyd ES. Phylogenomic analysis of novel Diaforarchaea is consistent with sulfite but not sulfate reduction in volcanic environments on early Earth. THE ISME JOURNAL 2020; 14:1316-1331. [PMID: 32066874 PMCID: PMC7174415 DOI: 10.1038/s41396-020-0611-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 01/28/2020] [Accepted: 02/04/2020] [Indexed: 12/27/2022]
Abstract
The origin(s) of dissimilatory sulfate and/or (bi)sulfite reducing organisms (SRO) remains enigmatic despite their importance in global carbon and sulfur cycling since at least 3.4 Ga. Here, we describe novel, deep-branching archaeal SRO populations distantly related to other Diaforarchaea from two moderately acidic thermal springs. Dissimilatory (bi)sulfite reductase homologs, DsrABC, encoded in metagenome assembled genomes (MAGs) from spring sediments comprise one of the earliest evolving Dsr lineages. DsrA homologs were expressed in situ under moderately acidic conditions. MAGs lacked genes encoding proteins that activate sulfate prior to (bi)sulfite reduction. This is consistent with sulfide production in enrichment cultures provided sulfite but not sulfate. We suggest input of volcanic sulfur dioxide to anoxic spring-water yields (bi)sulfite and moderately acidic conditions that favor its stability and bioavailability. The presence of similar volcanic springs at the time SRO are thought to have originated (>3.4 Ga) may have supplied (bi)sulfite that supported ancestral SRO. These observations coincide with the lack of inferred SO42- reduction capacity in nearly all organisms with early-branching DsrAB and which are near universally found in hydrothermal environments.
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Affiliation(s)
- Daniel R Colman
- Department of Microbiology & Immunology, Montana State University, Bozeman, MT, 59717, USA
| | - Melody R Lindsay
- Department of Microbiology & Immunology, Montana State University, Bozeman, MT, 59717, USA
| | - Maximiliano J Amenabar
- Department of Microbiology & Immunology, Montana State University, Bozeman, MT, 59717, USA
| | | | - Eric R Roden
- Department of Geoscience, University of Wisconsin, Madison, WI, USA
- NASA Astrobiology Institute, Mountain View, CA, USA
| | - Eric S Boyd
- Department of Microbiology & Immunology, Montana State University, Bozeman, MT, 59717, USA.
- NASA Astrobiology Institute, Mountain View, CA, USA.
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119
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Sabuda MC, Brazelton WJ, Putman LI, McCollom TM, Hoehler TM, Kubo MDY, Cardace D, Schrenk MO. A dynamic microbial sulfur cycle in a serpentinizing continental ophiolite. Environ Microbiol 2020; 22:2329-2345. [PMID: 32249550 DOI: 10.1111/1462-2920.15006] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Revised: 03/19/2020] [Accepted: 03/30/2020] [Indexed: 12/11/2022]
Abstract
Serpentinization is the hydration and oxidation of ultramafic rock, which occurs as oceanic lithosphere is emplaced onto continental margins (ophiolites), and along the seafloor as faulting exposes this mantle-derived material to circulating hydrothermal fluids. This process leads to distinctive fluid chemistries as molecular hydrogen (H2 ) and hydroxyl ions (OH- ) are produced and reduced carbon compounds are mobilized. Serpentinizing ophiolites also serve as a vector to transport sulfur compounds from the seafloor onto the continents. We investigated hyperalkaline, sulfur-rich, brackish groundwater in a serpentinizing continental ophiolite to elucidate the role of sulfur compounds in fuelling in situ microbial activities. Here we illustrate that key sulfur-cycling taxa, including Dethiobacter, Desulfitispora and 'Desulforudis', persist throughout this extreme environment. Biologically catalysed redox reactions involving sulfate, sulfide and intermediate sulfur compounds are thermodynamically favourable in the groundwater, which indicates they may be vital to sustaining life in these characteristically oxidant- and energy-limited systems. Furthermore, metagenomic and metatranscriptomic analyses reveal a complex network involving sulfate reduction, sulfide oxidation and thiosulfate reactions. Our findings highlight the importance of the complete inorganic sulfur cycle in serpentinizing fluids and suggest sulfur biogeochemistry provides a key link between terrestrial serpentinizing ecosystems and their submarine heritage.
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Affiliation(s)
- Mary C Sabuda
- Department of Earth and Environmental Sciences, Michigan State University, East Lansing, MI, 48824, USA
| | | | - Lindsay I Putman
- Department of Earth and Environmental Sciences, Michigan State University, East Lansing, MI, 48824, USA.,Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, 48824, USA
| | - Tom M McCollom
- Laboratory for Atmospheric and Space Physics, UCB 600, University of Colorado-Boulder, Boulder, CO, 80309, USA
| | - Tori M Hoehler
- Exobiology Branch, NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - Michael D Y Kubo
- Exobiology Branch, NASA Ames Research Center, Moffett Field, CA, 94035, USA.,SETI Institute, Mountain View, CA, 94043, USA
| | - Dawn Cardace
- Department of Geosciences, University of Rhode Island, Kingston, RI, 02881, USA
| | - Matthew O Schrenk
- Department of Earth and Environmental Sciences, Michigan State University, East Lansing, MI, 48824, USA.,Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, 48824, USA
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Abstract
Current understanding of the diversity, biology, and ecology of Archaea is very limited, especially considering how few of the known phyla have been cultured or genomically explored. The reconstruction of “Ca. Methanomixophus” MAGs not only expands the known range of metabolic versatility of the members of Archaeoglobi but also suggests that the phylogenetic distribution of MCR and MTR complexes is even wider than previously anticipated. Euryarchaeal lineages have been believed to have a methanogenic last common ancestor. However, members of euryarchaeal Archaeoglobi have long been considered nonmethanogenic and their evolutionary history remains elusive. Here, three high-quality metagenomic-assembled genomes (MAGs) retrieved from high-temperature oil reservoir and hot springs, together with three newly assembled Archaeoglobi MAGs from previously reported hot spring metagenomes, are demonstrated to represent a novel genus of Archaeoglobaceae, “Candidatus Methanomixophus.” All “Ca. Methanomixophus” MAGs encode an M methyltransferase (MTR) complex and a traditional type of methyl-coenzyme M reductase (MCR) complex, which is different from the divergent MCR complexes found in “Ca. Polytropus marinifundus.” In addition, “Ca. Methanomixophus dualitatem” MAGs preserve the genomic capacity for dissimilatory sulfate reduction. Comparative phylogenetic analysis supports a laterally transferred origin for an MCR complex and vertical heritage of the MTR complex in this lineage. Metatranscriptomic analysis revealed concomitant in situ activity of hydrogen-dependent methylotrophic methanogenesis and heterotrophic fermentation within populations of “Ca. Methanomixophus hydrogenotrophicum” in a high-temperature oil reservoir. IMPORTANCE Current understanding of the diversity, biology, and ecology of Archaea is very limited, especially considering how few of the known phyla have been cultured or genomically explored. The reconstruction of “Ca. Methanomixophus” MAGs not only expands the known range of metabolic versatility of the members of Archaeoglobi but also suggests that the phylogenetic distribution of MCR and MTR complexes is even wider than previously anticipated.
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121
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Moore RM, Harrison AO, McAllister SM, Polson SW, Wommack KE. Iroki: automatic customization and visualization of phylogenetic trees. PeerJ 2020; 8:e8584. [PMID: 32149022 PMCID: PMC7049256 DOI: 10.7717/peerj.8584] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 01/17/2020] [Indexed: 12/26/2022] Open
Abstract
Phylogenetic trees are an important analytical tool for evaluating community diversity and evolutionary history. In the case of microorganisms, the decreasing cost of sequencing has enabled researchers to generate ever-larger sequence datasets, which in turn have begun to fill gaps in the evolutionary history of microbial groups. However, phylogenetic analyses of these types of datasets create complex trees that can be challenging to interpret. Scientific inferences made by visual inspection of phylogenetic trees can be simplified and enhanced by customizing various parts of the tree. Yet, manual customization is time-consuming and error prone, and programs designed to assist in batch tree customization often require programming experience or complicated file formats for annotation. Iroki, a user-friendly web interface for tree visualization, addresses these issues by providing automatic customization of large trees based on metadata contained in tab-separated text files. Iroki’s utility for exploring biological and ecological trends in sequencing data was demonstrated through a variety of microbial ecology applications in which trees with hundreds to thousands of leaf nodes were customized according to extensive collections of metadata. The Iroki web application and documentation are available at https://www.iroki.net or through the VIROME portal http://virome.dbi.udel.edu. Iroki’s source code is released under the MIT license and is available at https://github.com/mooreryan/iroki.
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Affiliation(s)
- Ryan M Moore
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE, United States of America
| | - Amelia O Harrison
- School of Marine Science and Policy, University of Delaware, Newark, DE, United States of America
| | - Sean M McAllister
- School of Marine Science and Policy, University of Delaware, Newark, DE, United States of America
| | - Shawn W Polson
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE, United States of America
| | - K Eric Wommack
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE, United States of America
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122
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Klasek S, Torres ME, Bartlett DH, Tyler M, Hong W, Colwell F. Microbial communities from Arctic marine sediments respond slowly to methane addition during
ex situ
enrichments. Environ Microbiol 2020; 22:1829-1846. [DOI: 10.1111/1462-2920.14895] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 11/11/2019] [Accepted: 11/30/2019] [Indexed: 11/27/2022]
Affiliation(s)
- Scott Klasek
- Department of Microbiology Oregon State University Corvallis Oregon USA
| | - Marta E. Torres
- College of Earth, Ocean, and Atmospheric Sciences Oregon State University Corvallis Oregon USA
| | - Douglas H. Bartlett
- Marine Biology Research Division, Scripps Institution of Oceanography University of California San Diego California 92093‐0202 USA
| | - Madeline Tyler
- Department of Microbiology Oregon State University Corvallis Oregon USA
| | - Wei‐Li Hong
- Centre for Arctic Gas Hydrate, Environment and Climate (CAGE), Department of Geosciences UiT The Arctic University of Norway N‐9037 Tromsø Norway
| | - Frederick Colwell
- Department of Microbiology Oregon State University Corvallis Oregon USA
- College of Earth, Ocean, and Atmospheric Sciences Oregon State University Corvallis Oregon USA
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123
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Löffler M, Feldhues J, Venceslau SS, Kammler L, Grein F, Pereira IAC, Dahl C. DsrL mediates electron transfer between NADH and rDsrAB in Allochromatium vinosum. Environ Microbiol 2019; 22:783-795. [PMID: 31854015 DOI: 10.1111/1462-2920.14899] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 12/16/2019] [Accepted: 12/16/2019] [Indexed: 11/30/2022]
Abstract
Dissimilatory sulphite reductase DsrAB occurs in sulphate/sulphite-reducing prokaryotes, in sulphur disproportionators and also in sulphur oxidizers, where it functions in reverse. Predictions of physiological traits in metagenomic studies relying on the presence of dsrAB, other dsr genes or combinations thereof suffer from the lack of information on crucial Dsr proteins. The iron-sulphur flavoprotein DsrL is an example of this group. It has a documented essential function during sulphur oxidation and was recently also found in some metagenomes of probable sulphate and sulphite reducers. Here, we show that DsrL and reverse acting rDsrAB can form a complex and are copurified from the phototrophic sulphur oxidizer Allochromatium vinosum. Recombinant DsrL exhibits NAD(P)H:acceptor oxidoreductase activity with a strong preference for NADH over NADPH. In vitro, the rDsrABL complex effectively catalyses NADH-dependent sulphite reduction, which is strongly enhanced by the sulphur-binding protein DsrC. Our work reveals NAD+ as suitable in vivo electron acceptor for sulphur oxidation in organisms operating the rDsr pathway and points to reduced nicotinamide adenine dinucleotides as electron donors for sulphite reduction in sulphate/sulphite-reducing prokaryotes that contain DsrL. In addition, dsrL cannot be used as a marker distinguishing sulphate/sulphite reducers and sulphur oxidizers in metagenomic studies without further analysis.
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Affiliation(s)
- Maria Löffler
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Julia Feldhues
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Sofia S Venceslau
- Instituto de Tecnologia Química e Biológica Antonio Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Lydia Kammler
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Fabian Grein
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Inês A C Pereira
- Instituto de Tecnologia Química e Biológica Antonio Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Christiane Dahl
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
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Pelikan C, Jaussi M, Wasmund K, Seidenkrantz MS, Pearce C, Kuzyk ZZA, Herbold CW, Røy H, Kjeldsen KU, Loy A. Glacial Runoff Promotes Deep Burial of Sulfur Cycling-Associated Microorganisms in Marine Sediments. Front Microbiol 2019; 10:2558. [PMID: 31787951 PMCID: PMC6853847 DOI: 10.3389/fmicb.2019.02558] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 10/23/2019] [Indexed: 12/22/2022] Open
Abstract
Marine fjords with active glacier outlets are hot spots for organic matter burial in the sediments and subsequent microbial mineralization. Here, we investigated controls on microbial community assembly in sub-arctic glacier-influenced (GI) and non-glacier-influenced (NGI) marine sediments in the Godthåbsfjord region, south-western Greenland. We used a correlative approach integrating 16S rRNA gene and dissimilatory sulfite reductase (dsrB) amplicon sequence data over six meters of depth with biogeochemistry, sulfur-cycling activities, and sediment ages. GI sediments were characterized by comparably high sedimentation rates and had "young" sediment ages of <500 years even at 6 m sediment depth. In contrast, NGI stations reached ages of approximately 10,000 years at these depths. Sediment age-depth relationships, sulfate reduction rates (SRR), and C/N ratios were strongly correlated with differences in microbial community composition between GI and NGI sediments, indicating that age and diagenetic state were key drivers of microbial community assembly in subsurface sediments. Similar bacterial and archaeal communities were present in the surface sediments of all stations, whereas only in GI sediments were many surface taxa also abundant through the whole sediment core. The relative abundance of these taxa, including diverse Desulfobacteraceae members, correlated positively with SRRs, indicating their active contributions to sulfur-cycling processes. In contrast, other surface community members, such as Desulfatiglans, Atribacteria, and Chloroflexi, survived the slow sediment burial at NGI stations and dominated in the deepest sediment layers. These taxa are typical for the energy-limited marine deep biosphere and their relative abundances correlated positively with sediment age. In conclusion, our data suggests that high rates of sediment accumulation caused by glacier runoff and associated changes in biogeochemistry, promote persistence of sulfur-cycling activity and burial of a larger fraction of the surface microbial community into the deep subsurface.
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Affiliation(s)
- Claus Pelikan
- Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
- Austrian Polar Research Institute, Vienna, Austria
| | - Marion Jaussi
- Center for Geomicrobiology, Section for Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Kenneth Wasmund
- Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
- Austrian Polar Research Institute, Vienna, Austria
| | - Marit-Solveig Seidenkrantz
- Palaeoceanography and Palaeoclimate Group, Arctic Research Centre, and iClimate Interdisciplinary Centre for Climate Change, Department of Geoscience, Aarhus University, Aarhus, Denmark
| | - Christof Pearce
- Palaeoceanography and Palaeoclimate Group, Arctic Research Centre, and iClimate Interdisciplinary Centre for Climate Change, Department of Geoscience, Aarhus University, Aarhus, Denmark
| | - Zou Zou Anna Kuzyk
- Department of Geological Sciences, Centre for Earth Observation Science, University of Manitoba, Winnipeg, MB, Canada
| | - Craig W. Herbold
- Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Hans Røy
- Center for Geomicrobiology, Section for Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Kasper Urup Kjeldsen
- Center for Geomicrobiology, Section for Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Alexander Loy
- Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
- Austrian Polar Research Institute, Vienna, Austria
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125
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Koziaeva V, Dziuba M, Leão P, Uzun M, Krutkina M, Grouzdev D. Genome-Based Metabolic Reconstruction of a Novel Uncultivated Freshwater Magnetotactic coccus " Ca. Magnetaquicoccus inordinatus" UR-1, and Proposal of a Candidate Family " Ca. Magnetaquicoccaceae". Front Microbiol 2019; 10:2290. [PMID: 31632385 PMCID: PMC6783814 DOI: 10.3389/fmicb.2019.02290] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 09/19/2019] [Indexed: 12/20/2022] Open
Abstract
Magnetotactic bacteria are widely represented microorganisms that have the ability to synthesize magnetosomes. The magnetotactic cocci of the order Magnetococcales are the most frequently identified, but their classification remains unclear due to the low number of cultivated representatives. This paper reports the analysis of an uncultivated magnetotactic coccus UR-1 collected from the Uda River (in eastern Siberia). Genome analyses of this bacterium and comparison to the available Magnetococcales genomes identified a novel species called "Ca. Magnetaquicoccus inordinatus," and a delineated candidate family "Ca. Magnetaquicoccaceae" within the order Magnetococcales is proposed. We used average amino acid identity values <55-56% and <64-65% as thresholds for the separation of families and genera, respectively, within the order Magnetococcales. Analyses of the genome sequence of UR-1 revealed a potential ability for a chemolithoautotrophic lifestyle, with the oxidation of a reduced sulfur compound and carbon assimilation by rTCA. A nearly complete magnetosome genome island, containing a set of mam and mms genes, was also identified. Further comparative analyses of the magnetosome genes showed vertical inheritance as well as horizontal gene transfer as the evolutionary drivers of magnetosome biomineralization genes in strains of the order Magnetococcales.
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Affiliation(s)
- Veronika Koziaeva
- Research Center of Biotechnology of the Russian Academy of Sciences, Institute of Bioengineering, Moscow, Russia
| | - Marina Dziuba
- Research Center of Biotechnology of the Russian Academy of Sciences, Institute of Bioengineering, Moscow, Russia
- Department of Microbiology, University of Bayreuth, Bayreuth, Germany
| | - Pedro Leão
- Instituto de Microbiologia Paulo de Góes, Universidade Federal Do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Maria Uzun
- Research Center of Biotechnology of the Russian Academy of Sciences, Institute of Bioengineering, Moscow, Russia
- Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Maria Krutkina
- Research Center of Biotechnology of the Russian Academy of Sciences, Institute of Bioengineering, Moscow, Russia
| | - Denis Grouzdev
- Research Center of Biotechnology of the Russian Academy of Sciences, Institute of Bioengineering, Moscow, Russia
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126
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Cable bacteria, living electrical conduits in the microbial world. Proc Natl Acad Sci U S A 2019; 116:18759-18761. [PMID: 31501332 DOI: 10.1073/pnas.1913413116] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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127
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Payne D, Dunham EC, Mohr E, Miller I, Arnold A, Erickson R, Fones EM, Lindsay MR, Colman DR, Boyd ES. Geologic legacy spanning >90 years explains unique Yellowstone hot spring geochemistry and biodiversity. Environ Microbiol 2019; 21:4180-4195. [PMID: 31397054 DOI: 10.1111/1462-2920.14775] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 07/30/2019] [Accepted: 07/31/2019] [Indexed: 01/09/2023]
Abstract
Little is known about how the geological history of an environment shapes its physical and chemical properties and how these, in turn, influence the assembly of communities. Evening primrose (EP), a moderately acidic hot spring (pH 5.6, 77.4°C) in Yellowstone National Park (YNP), has undergone dramatic physicochemical change linked to seismic activity. Here, we show that this legacy of geologic change led to the development of an unusual sulphur-rich, anoxic chemical environment that supports a unique archaeal-dominated and anaerobic microbial community. Metagenomic sequencing and informatics analyses reveal that >96% of this community is supported by dissimilatory reduction or disproportionation of inorganic sulphur compounds, including a novel, deeply diverging sulphate-reducing thaumarchaeote. When compared to other YNP metagenomes, the inferred functions of EP populations were like those from sulphur-rich acidic springs, suggesting that sulphur may overprint the predominant influence of pH on the composition of hydrothermal communities. Together, these observations indicate that the dynamic geological history of EP underpins its unique geochemistry and biodiversity, emphasizing the need to consider the legacy of geologic change when describing processes that shape the assembly of communities.
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Affiliation(s)
- Devon Payne
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana, 59717
| | - Eric C Dunham
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana, 59717
| | - Elizabeth Mohr
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, Montana, 59717
| | - Isaac Miller
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana, 59717
| | - Adrienne Arnold
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana, 59717
| | - Reece Erickson
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana, 59717
| | - Elizabeth M Fones
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana, 59717
| | - Melody R Lindsay
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana, 59717
| | - Daniel R Colman
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana, 59717
| | - Eric S Boyd
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana, 59717
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128
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Vavourakis CD, Mehrshad M, Balkema C, van Hall R, Andrei AŞ, Ghai R, Sorokin DY, Muyzer G. Metagenomes and metatranscriptomes shed new light on the microbial-mediated sulfur cycle in a Siberian soda lake. BMC Biol 2019; 17:69. [PMID: 31438955 PMCID: PMC6704655 DOI: 10.1186/s12915-019-0688-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 08/09/2019] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND The planetary sulfur cycle is a complex web of chemical reactions that can be microbial-mediated or can occur spontaneously in the environment, depending on the temperature and pH. Inorganic sulfur compounds can serve as energy sources for specialized prokaryotes and are important substrates for microbial growth in general. Here, we investigate dissimilatory sulfur cycling in the brine and sediments of a southwestern Siberian soda lake characterized by an extremely high pH and salinity, combining meta-omics analyses of its uniquely adapted highly diverse prokaryote communities with biogeochemical profiling to identify key microbial players and expand our understanding of sulfur cycling under haloalkaline conditions. RESULTS Peak microbial activity was found in the top 4 cm of the sediments, a layer with a steep drop in oxygen concentration and redox potential. The majority of sulfur was present as sulfate or iron sulfide. Thiosulfate was readily oxidized by microbes in the presence of oxygen, but oxidation was partially inhibited by light. We obtained 1032 metagenome-assembled genomes, including novel population genomes of characterized colorless sulfur-oxidizing bacteria (SOB), anoxygenic purple sulfur bacteria, heterotrophic SOB, and highly active lithoautotrophic sulfate reducers. Surprisingly, we discovered the potential for nitrogen fixation in a new genus of colorless SOB, carbon fixation in a new species of phototrophic Gemmatimonadetes, and elemental sulfur/sulfite reduction in the "Candidatus Woesearchaeota." Polysulfide/thiosulfate and tetrathionate reductases were actively transcribed by various (facultative) anaerobes. CONCLUSIONS The recovery of over 200 genomes that encoded enzymes capable of catalyzing key reactions in the inorganic sulfur cycle indicates complete cycling between sulfate and sulfide at moderately hypersaline and extreme alkaline conditions. Our results suggest that more taxonomic groups are involved in sulfur dissimilation than previously assumed.
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Affiliation(s)
- Charlotte D Vavourakis
- Microbial Systems Ecology, Department of Freshwater and Marine Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE, Amsterdam, the Netherlands
| | - Maliheh Mehrshad
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre of the Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic
| | - Cherel Balkema
- Microbial Systems Ecology, Department of Freshwater and Marine Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE, Amsterdam, the Netherlands
| | - Rutger van Hall
- Department of Ecosystem & Landscape Dynamics, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, the Netherlands
| | - Adrian-Ştefan Andrei
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre of the Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic
| | - Rohit Ghai
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre of the Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic
| | - Dimitry Y Sorokin
- Winogradsky Institute of Microbiology, Research Centre of Biotechnology, Russian Academy of Sciences, Moscow, Russian Federation
- Department of Biotechnology, Environmental Biotechnology, Delft University of Technology, Delft, the Netherlands
| | - Gerard Muyzer
- Microbial Systems Ecology, Department of Freshwater and Marine Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE, Amsterdam, the Netherlands.
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129
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Luo Y, Atashgahi S, Rijnaarts HHM, Comans RNJ, Sutton NB. Influence of different redox conditions and dissolved organic matter on pesticide biodegradation in simulated groundwater systems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 677:692-699. [PMID: 31071671 DOI: 10.1016/j.scitotenv.2019.04.128] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 04/08/2019] [Accepted: 04/09/2019] [Indexed: 06/09/2023]
Abstract
Insights into the influence of redox conditions, that is the availability of electron acceptors, and dissolved organic matter (DOM) on pesticide biodegradation in groundwater are key to understanding the environmental fate of pesticides in natural groundwater systems. Here, the influence of redox conditions and supplemental DOM addition on biodegradation of pesticides, 2,4-dichlorophenoxyacetic acid (2,4-D), 2,6-dichlorobenzamide (BAM), mecoprop-p (MCPP) and bentazone, was tested in microcosm and subsequent column experiments. Pesticide degradation, functional genes and changes in specific fractions and quantity of DOM were systematically quantified. In aerobic microcosm experiments, the highest 2,4-D degradation rate was obtained with the presence of more assimilable DOM. In column experiments, minimal pesticide degradation (≤33.77%) in any anaerobic redox conditions was observed in the absence of DOM. However, in the presence of DOM, 2,4-D biodegradation was considerably enhanced under nitrate-reducing conditions (from 23.5 ± 10.2% to 82.3 ± 11.6%) and in a column without external electron acceptor amendment (from -6.3 ± 12.6% to 31.1 ± 36.3%). Observed preferential depletion of the fulvic acid fraction of DOM provides indications for specific functional DOM properties. The qPCR results show an increase in microbial biomass and functional genes (tfdA) in liquid phase after DOM addition. The results of this work provide insights into the interplays among DOM, redox geochemistry, and pesticide biodegradation, and show the potential of a novel approach - DOM addition to groundwater systems - for in situ biostimulation technology to remove pesticides from groundwater systems.
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Affiliation(s)
- Yujia Luo
- Sub-department of Environmental Technology, Wageningen University & Research, P.O. Box 47, 6700 AA Wageningen, the Netherlands
| | - Siavash Atashgahi
- Laboratory of Microbiology, Wageningen University & Research, P.O. Box 47, 6700 AA Wageningen, the Netherlands
| | - Huub H M Rijnaarts
- Sub-department of Environmental Technology, Wageningen University & Research, P.O. Box 47, 6700 AA Wageningen, the Netherlands
| | - Rob N J Comans
- Department of Soil Quality, Wageningen University, P.O. Box 47, 6700 AA Wageningen, the Netherlands
| | - Nora B Sutton
- Sub-department of Environmental Technology, Wageningen University & Research, P.O. Box 47, 6700 AA Wageningen, the Netherlands.
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130
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Sarker NC, Borhan M, Fortuna AM, Rahman S. Understanding gaseous reduction in swine manure resulting from nanoparticle treatments under anaerobic storage conditions. J Environ Sci (China) 2019; 82:179-191. [PMID: 31133263 DOI: 10.1016/j.jes.2019.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 03/06/2019] [Accepted: 03/07/2019] [Indexed: 06/09/2023]
Abstract
Manure is an impending source of carbon (C), sulfur (S) and water (H2O). Consequently, microbial populations utilize these constituents to produce methane (CH4), carbon dioxide (CO2), greenhouse gases (GHGs), and hydrogen sulfide (H2S). Application of nanoparticles (NPs) to stored manure is an emerging GHG mitigation technique. In this study, two NPs: nano zinc oxide (nZnO) and nano silver (nAg) were tested in swine manure stored under anaerobic conditions to determine their effectiveness in mitigating gaseous emissions and total gas production. The biological sources of gas production, i.e., microbial populations were characterized via Quantitative Polymerase Chain Reaction (qPCR) analysis. Additionally, pH, redox, and VFAs were determined using standard methods. Each treatment of the experiment was replicated three times and NPs were applied at a dose of 3 g/L of manure. Also, headspace gas from all treatment replicates were analyzed for CH4 and CO2 gas concentrations using an SRI-8610 Gas Chromatograph and H2S concentrations were measured using a Jerome 631X meter. Nanoparticles tested in this study reduced the cumulative gas volume by 16%-79% compared to the control. Among the NPs tested, only nZnO consistently reduced GHG concentrations by 37%-97%. Reductions in H2S concentrations ranged from 87% to 97%. Gaseous reductions were likely due to decreases in the activity and numbers of specific gas producing methanogenic archaea and sulfate reducing bacterial (SRB) species.
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Affiliation(s)
- Niloy Chandra Sarker
- Agricultural and Biosystems Engineering Department, North Dakota State University, Fargo, ND 58108, USA
| | - Md Borhan
- Agricultural and Biosystems Engineering Department, North Dakota State University, Fargo, ND 58108, USA
| | - Ann-Marie Fortuna
- USDA-ARS, Grazinglands Research Laboratory, 7207 West, Sheyenne Street, El Reno, OK 73036, USA
| | - Shafiqur Rahman
- Agricultural and Biosystems Engineering Department, North Dakota State University, Fargo, ND 58108, USA.
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131
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Tan S, Liu J, Fang Y, Hedlund BP, Lian ZH, Huang LY, Li JT, Huang LN, Li WJ, Jiang HC, Dong HL, Shu WS. Insights into ecological role of a new deltaproteobacterial order Candidatus Acidulodesulfobacterales by metagenomics and metatranscriptomics. THE ISME JOURNAL 2019; 13:2044-2057. [PMID: 30962514 PMCID: PMC6776010 DOI: 10.1038/s41396-019-0415-y] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 02/15/2019] [Accepted: 03/24/2019] [Indexed: 12/21/2022]
Abstract
Several abundant but yet uncultivated bacterial groups exist in extreme iron- and sulfur-rich environments, and the physiology, biodiversity, and ecological roles of these bacteria remain a mystery. Here we retrieved four metagenome-assembled genomes (MAGs) from an artificial acid mine drainage (AMD) system, and propose they belong to a new deltaproteobacterial order, Candidatus Acidulodesulfobacterales. The distribution pattern of Ca. Acidulodesulfobacterales in AMDs across Southeast China correlated strongly with ferrous iron. Reconstructed metabolic pathways and gene expression profiles showed that they were likely facultatively anaerobic autotrophs capable of nitrogen fixation. In addition to dissimilatory sulfate reduction, encoded by dsrAB, dsrD, dsrL, and dsrEFH genes, these microorganisms might also oxidize sulfide, depending on oxygen concentration and/or oxidation reduction potential. Several genes with homology to those involved in iron metabolism were also identified, suggesting their potential role in iron cycling. In addition, the expression of abundant resistance genes revealed the mechanisms of adaptation and response to the extreme environmental stresses endured by these organisms in the AMD environment. These findings shed light on the distribution, diversity, and potential ecological role of the new order Ca. Acidulodesulfobacterales in nature.
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Affiliation(s)
- Sha Tan
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, 510275, Guangzhou, China
| | - Jun Liu
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, 510275, Guangzhou, China
- Department of Geology and Environmental Earth Science, Miami University, Oxford, OH, 45056, USA
| | - Yun Fang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 430074, Wuhan, China
| | - Brian P Hedlund
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV, 89154, USA
- Nevada Institute of Personalized Medicine, University of Nevada Las Vegas, Las Vegas, NV, 89154, USA
| | - Zheng-Han Lian
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, 510275, Guangzhou, China
- Guangdong Magigene Biotechnology Co. Ltd., 510000, Guangzhou, China
| | - Li-Ying Huang
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, 510275, Guangzhou, China
| | - Jin-Tian Li
- School of Life Sciences, South China Normal University, 510631, Guangzhou, China
| | - Li-Nan Huang
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, 510275, Guangzhou, China
| | - Wen-Jun Li
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, 510275, Guangzhou, China
| | - Hong-Chen Jiang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 430074, Wuhan, China
| | - Hai-Liang Dong
- Department of Geology and Environmental Earth Science, Miami University, Oxford, OH, 45056, USA.
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 100083, Beijing, China.
| | - Wen-Sheng Shu
- School of Life Sciences, South China Normal University, 510631, Guangzhou, China.
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132
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Luk AW, Beckmann S, Manefield M. Dependency of DNA extraction efficiency on cell concentration confounds molecular quantification of microorganisms in groundwater. FEMS Microbiol Ecol 2019; 94:5066166. [PMID: 30137345 DOI: 10.1093/femsec/fiy146] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Accepted: 08/01/2018] [Indexed: 12/13/2022] Open
Abstract
Quantification of microbes in water systems is essential to industrial practices ranging from drinking water and wastewater treatment to groundwater remediation. While quantification using DNA-based molecular methods is precise, the accuracy is dependent on DNA extraction efficiencies. We show that the DNA yield is strongly impacted by the cell concentration in groundwater samples (r = -0.92, P < 0.0001). This has major implications for industrial applications using quantitative polymerase chain reaction (qPCR) to determine cell concentrations in water, including bioremediation. We propose a simple normalization method using a DNA recovery ratio, calculated with the total cell count and DNA yield. Application of this method to enumeration of bacteria and archaea in groundwater samples targeting phylogenetic markers (16S rRNA) demonstrated an increased goodness of fit after normalization (7.04 vs 0.94 difference in Akaike's information criteria). Furthermore, normalization was applied to qPCR quantification of functional genes and combined with DNA sequencing of archaeal and bacterial 16S rRNA genes to monitor changes in abundance of methanogenic archaea and sulphate-reducing bacteria in groundwater. The integration of qPCR and DNA sequencing with appropriate normalization enables high-throughput quantification of microbial groups using increasingly affordable and accessible techniques. This research has implications for microbial ecology and engineering research as well as industrial practice.
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Affiliation(s)
- Alison Ws Luk
- School of Chemical Engineering, University of New South Wales, NSW 2052, Australia
| | - Sabrina Beckmann
- School of Chemical Engineering, University of New South Wales, NSW 2052, Australia
| | - Mike Manefield
- School of Chemical Engineering, University of New South Wales, NSW 2052, Australia.,School of Civil and Environmental Engineering, University of New South Wales, NSW 2052, Australia
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133
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Ranchou-Peyruse M, Auguet JC, Mazière C, Restrepo-Ortiz CX, Guignard M, Dequidt D, Chiquet P, Cézac P, Ranchou-Peyruse A. Geological gas-storage shapes deep life. Environ Microbiol 2019; 21:3953-3964. [PMID: 31314939 DOI: 10.1111/1462-2920.14745] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 07/14/2019] [Indexed: 11/28/2022]
Abstract
Around the world, several dozen deep sedimentary aquifers are being used for storage of natural gas. Ad hoc studies of the microbial ecology of some of them have suggested that sulfate reducing and methanogenic microorganisms play a key role in how these aquifers' communities function. Here, we investigate the influence of gas storage on these two metabolic groups by using high-throughput sequencing and show the importance of sulfate-reducing Desulfotomaculum and a new monophyletic methanogenic group. Aquifer microbial diversity was significantly related to the geological level. The distance to the stored natural gas affects the ratio of sulfate-reducing Firmicutes to deltaproteobacteria. In only one aquifer, the methanogenic archaea dominate the sulfate-reducers. This aquifer was used to store town gas (containing at least 50% H2 ) around 50 years ago. The observed decrease of sulfates in this aquifer could be related to stimulation of subsurface sulfate-reducers. These results suggest that the composition of the microbial communities is impacted by decades old transient gas storage activity. The tremendous stability of these gas-impacted deep subsurface microbial ecosystems suggests that in situ biotic methanation projects in geological reservoirs may be sustainable over time.
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Affiliation(s)
- Magali Ranchou-Peyruse
- CNRS/Univ Pau & Pays Adour/E2S-UPPA, Institut des Sciences Analytiques et de Physicochimie pour l'Environnement et les Matériaux, UMR5254, 000, Pau, France
| | - Jean-Christophe Auguet
- MARBEC, Montpellier University, CNRS, IFREMER, IRD, Place Eugène Bataillon, Montpellier, France
| | - Camille Mazière
- CNRS/Univ Pau & Pays Adour/E2S-UPPA, Institut des Sciences Analytiques et de Physicochimie pour l'Environnement et les Matériaux, UMR5254, 000, Pau, France.,MARBEC, Montpellier University, CNRS, IFREMER, IRD, Place Eugène Bataillon, Montpellier, France
| | | | - Marion Guignard
- CNRS/Univ Pau & Pays Adour/E2S-UPPA, Institut des Sciences Analytiques et de Physicochimie pour l'Environnement et les Matériaux, UMR5254, 000, Pau, France
| | - David Dequidt
- STORENGY - Geosciences Department, Bois-Colombes, France
| | | | - Pierre Cézac
- Laboratoire de Thermique, Énergétique et Procédés IPRA, EA1932, Univ Pau & Pays Adour/E2S-UPPA, 000, Pau, France
| | - Anthony Ranchou-Peyruse
- CNRS/Univ Pau & Pays Adour/E2S-UPPA, Institut des Sciences Analytiques et de Physicochimie pour l'Environnement et les Matériaux, UMR5254, 000, Pau, France
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134
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Pinnell LJ, Turner JW. Shotgun Metagenomics Reveals the Benthic Microbial Community Response to Plastic and Bioplastic in a Coastal Marine Environment. Front Microbiol 2019; 10:1252. [PMID: 31231339 PMCID: PMC6566015 DOI: 10.3389/fmicb.2019.01252] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 05/20/2019] [Indexed: 11/23/2022] Open
Abstract
Plastic is incredibly abundant in marine environments but little is known about its effects on benthic microbiota and biogeochemical cycling. This study reports the shotgun metagenomic sequencing of biofilms fouling plastic and bioplastic microcosms staged at the sediment–water interface of a coastal lagoon. Community composition analysis revealed that plastic biofilms were indistinguishable in comparison to a ceramic biofilm control. By contrast, bioplastic biofilms were distinct and dominated by sulfate-reducing microorganisms (SRM). Analysis of bioplastic gene pools revealed the enrichment of esterases, depolymerases, adenylyl sulfate reductases (aprBA), and dissimilatory sulfite reductases (dsrAB). The nearly 20-fold enrichment of a phylogenetically diverse polyhydroxybutyrate (PHB) depolymerase suggests this gene was distributed across a mixed microbial assemblage. The metagenomic reconstruction of genomes identified novel species of Desulfovibrio, Desulfobacteraceae, and Desulfobulbaceae among the abundant SRM, and these genomes contained genes integral to both bioplastic degradation and sulfate reduction. Findings indicate that bioplastic promoted a rapid and significant shift in benthic microbial diversity and gene pools, selecting for microbes that participate in bioplastic degradation and sulfate reduction. If plastic pollution is traded for bioplastic pollution and sedimentary inputs are large, the microbial response could unintentionally affect benthic biogeochemical activities through the stimulation of sulfate reducers.
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Affiliation(s)
- Lee J Pinnell
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, TX, United States
| | - Jeffrey W Turner
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, TX, United States
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135
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Cetecioglu Z, Dolfing J, Taylor J, Purdy KJ, Eyice Ö. COD/sulfate ratio does not affect the methane yield and microbial diversity in anaerobic digesters. WATER RESEARCH 2019; 155:444-454. [PMID: 30861382 DOI: 10.1016/j.watres.2019.02.038] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 02/19/2019] [Accepted: 02/21/2019] [Indexed: 06/09/2023]
Abstract
Anaerobic digestion of organic matter is the major route of biomethane production. However, in the presence of sulfate, sulfate-reducing bacteria (SRB) typically outcompete methanogens, which may reduce or even preclude methane production from sulfate-containing wastewaters. Although sulfate-reduction and methanogenesis can occur simultaneously, our limited understanding of the microbiology of anaerobic digesters treating sulfate-containing wastewaters constrains improvements in the production of methane from these systems. This study tested the effects of carbon sources and chemical oxygen demand-to-sulfate ratio (COD/SO42-) on the diversity and interactions of SRB and methanogens in an anaerobic digester treating a high-sulfate waste stream. Overall, the data showed that sulfate removal and methane generation occurred in varying efficiencies and the carbon source had limited effect on the methane yield. Importantly, the results demonstrated that methanogenic and SRB diversities were only affected by the carbon source and not by the COD/SO42- ratio.
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Affiliation(s)
- Zeynep Cetecioglu
- School of Chemical Science and Engineering, KTH Royal Institute of Technology, SE-100 44, Sweden; School of Life Sciences, University of Warwick, CV4 7AL, UK
| | - Jan Dolfing
- School of Engineering, Newcastle University, NE1 7RU, UK
| | - Jessica Taylor
- School of Life Sciences, University of Warwick, CV4 7AL, UK
| | - Kevin J Purdy
- School of Life Sciences, University of Warwick, CV4 7AL, UK
| | - Özge Eyice
- School of Biological and Chemical Sciences, Queen Mary University of London, E1 4NS, UK.
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136
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Saunders JK, Fuchsman CA, McKay C, Rocap G. Complete arsenic-based respiratory cycle in the marine microbial communities of pelagic oxygen-deficient zones. Proc Natl Acad Sci U S A 2019; 116:9925-9930. [PMID: 31036654 PMCID: PMC6525544 DOI: 10.1073/pnas.1818349116] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Microbial capacity to metabolize arsenic is ancient, arising in response to its pervasive presence in the environment, which was largely in the form of As(III) in the early anoxic ocean. Many biological arsenic transformations are aimed at mitigating toxicity; however, some microorganisms can respire compounds of this redox-sensitive element to reap energetic gains. In several modern anoxic marine systems concentrations of As(V) are higher relative to As(III) than what would be expected from the thermodynamic equilibrium, but the mechanism for this discrepancy has remained unknown. Here we present evidence of a complete respiratory arsenic cycle, consisting of dissimilatory As(V) reduction and chemoautotrophic As(III) oxidation, in the pelagic ocean. We identified the presence of genes encoding both subunits of the respiratory arsenite oxidase AioA and the dissimilatory arsenate reductase ArrA in the Eastern Tropical North Pacific (ETNP) oxygen-deficient zone (ODZ). The presence of the dissimilatory arsenate reductase gene arrA was enriched on large particles (>30 um), similar to the forward bacterial dsrA gene of sulfate-reducing bacteria, which is involved in the cryptic cycling of sulfur in ODZs. Arsenic respiratory genes were expressed in metatranscriptomic libraries from the ETNP and the Eastern Tropical South Pacific (ETSP) ODZ, indicating arsenotrophy is a metabolic pathway actively utilized in anoxic marine water columns. Together these results suggest arsenic-based metabolisms support organic matter production and impact nitrogen biogeochemical cycling in modern oceans. In early anoxic oceans, especially during periods of high marine arsenic concentrations, they may have played a much larger role.
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Affiliation(s)
| | - Clara A Fuchsman
- School of Oceanography, University of Washington, Seattle, WA 98195
| | - Cedar McKay
- School of Oceanography, University of Washington, Seattle, WA 98195
| | - Gabrielle Rocap
- School of Oceanography, University of Washington, Seattle, WA 98195
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137
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Qin H, Wang S, Feng K, He Z, Virta MPJ, Hou W, Dong H, Deng Y. Unraveling the diversity of sedimentary sulfate-reducing prokaryotes (SRP) across Tibetan saline lakes using epicPCR. MICROBIOME 2019; 7:71. [PMID: 31054577 PMCID: PMC6500586 DOI: 10.1186/s40168-019-0688-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 04/25/2019] [Indexed: 05/07/2023]
Abstract
Sulfate reduction is an important biogeochemical process in the ecosphere; however, the major taxa of sulfate reducers have not been fully identified. Here, we used epicPCR (Emulsion, Paired Isolation, and Concatenation PCR) technology to identify the phylogeny of sulfate-reducing prokaryotes (SRP) in sediments from Tibetan Plateau saline lakes. A total of 12,519 OTUs and 883 SRP-OTUs were detected in ten lakes by sequencing of 16S rRNA gene PCR amplicons and epicPCR products of fused 16S rRNA plus dsrB gene, respectively, with Proteobacteria, Firmicutes, and Bacteroidetes being the dominant phyla in both datasets. The 120 highly abundant SRP-OTUs (> 1% in at least one sample) were affiliated with 17 described phyla, only 7 of which are widely recognized as SRP phyla. The majority of OTUs from both the whole microbial communities and the SRPs were not detected in more than one specific lake, suggesting high levels of endemism. The α-diversity of the entire microbial community and SRP sub-community showed significant positive correlations. The pH value and mean water temperature of the month prior to sampling were the environmental determinants for the whole microbial community, while the mean water temperature and total nitrogen were the major environmental drivers for the SRP sub-community. This study revealed there are still many undocumented SRP in Tibetan saline lakes, many of which could be endemic and adapted to specific environmental conditions.
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Affiliation(s)
- Huayu Qin
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Rd, Haidian, Beijing, 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shang Wang
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Rd, Haidian, Beijing, 100085, China
| | - Kai Feng
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Rd, Haidian, Beijing, 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhili He
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Marko P J Virta
- Department of Environmental Sciences, University of Helsinki, 00014, Helsinki, Finland
| | - Weiguo Hou
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, China
| | - Hailiang Dong
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, China
- Department of Geology and Environmental Earth Science, Miami University, Oxford, OH, United States
| | - Ye Deng
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Rd, Haidian, Beijing, 100085, China.
- Institute for Marine Science and Technology, Shandong University, Qingdao, 266237, China.
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China.
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138
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Boyd JA, Jungbluth SP, Leu AO, Evans PN, Woodcroft BJ, Chadwick GL, Orphan VJ, Amend JP, Rappé MS, Tyson GW. Divergent methyl-coenzyme M reductase genes in a deep-subseafloor Archaeoglobi. THE ISME JOURNAL 2019; 13:1269-1279. [PMID: 30651609 PMCID: PMC6474303 DOI: 10.1038/s41396-018-0343-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 11/29/2018] [Accepted: 12/11/2018] [Indexed: 12/28/2022]
Abstract
The methyl-coenzyme M reductase (MCR) complex is a key enzyme in archaeal methane generation and has recently been proposed to also be involved in the oxidation of short-chain hydrocarbons including methane, butane, and potentially propane. The number of archaeal clades encoding the MCR continues to grow, suggesting that this complex was inherited from an ancient ancestor, or has undergone extensive horizontal gene transfer. Expanding the representation of MCR-encoding lineages through metagenomic approaches will help resolve the evolutionary history of this complex. Here, a near-complete Archaeoglobi metagenome-assembled genome (MAG; Ca. Polytropus marinifundus gen. nov. sp. nov.) was recovered from the deep subseafloor along the Juan de Fuca Ridge flank that encodes two divergent McrABG operons similar to those found in Ca. Bathyarchaeota and Ca. Syntrophoarchaeum MAGs. Ca. P. marinifundus is basal to members of the class Archaeoglobi, and encodes the genes for β-oxidation, potentially allowing an alkanotrophic metabolism similar to that proposed for Ca. Syntrophoarchaeum. Ca. P. marinifundus also encodes a respiratory electron transport chain that can potentially utilize nitrate, iron, and sulfur compounds as electron acceptors. Phylogenetic analysis suggests that the Ca. P. marinifundus MCR operons were horizontally transferred, changing our understanding of the evolution and distribution of this complex in the Archaea.
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Affiliation(s)
- Joel A Boyd
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, QLD, Australia
| | - Sean P Jungbluth
- Center for Dark Energy Biosphere Investigations, University of Southern California, Los Angeles, CA, USA
- Department of Energy, Joint Genome Institute, Walnut Creek, CA, USA
| | - Andy O Leu
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, QLD, Australia
| | - Paul N Evans
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, QLD, Australia
| | - Ben J Woodcroft
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, QLD, Australia
| | - Grayson L Chadwick
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | - Victoria J Orphan
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | - Jan P Amend
- Departments of Earth Sciences and Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Michael S Rappé
- Hawaii Institute of Marine Biology, University of Hawaii at Manoa, Kaneohe, HI, USA
| | - Gene W Tyson
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, QLD, Australia.
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139
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Dietary Factors in Sulfur Metabolism and Pathogenesis of Ulcerative Colitis. Nutrients 2019; 11:nu11040931. [PMID: 31027194 PMCID: PMC6521024 DOI: 10.3390/nu11040931] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Revised: 04/20/2019] [Accepted: 04/23/2019] [Indexed: 02/07/2023] Open
Abstract
The biogeography of inflammation in ulcerative colitis (UC) suggests a proximal to distal concentration gradient of a toxin. Hydrogen sulfide (H2S) has long been considered one such toxin candidate, and dietary sulfur along with the abundance of sulfate reducing bacteria (SRB) were considered the primary determinants of H2S production and clinical course of UC. The metabolic milieu in the lumen of the colon, however, is the result of a multitude of factors beyond dietary sulfur intake and SRB abundance. Here we present an updated formulation of the H2S toxin hypothesis for UC pathogenesis, which strives to incorporate the interdependency of diet composition and the metabolic activity of the entire colon microbial community. Specifically, we suggest that the increasing severity of inflammation along the proximal-to-distal axis in UC is due to the dilution of beneficial factors, concentration of toxic factors, and changing detoxification capacity of the host, all of which are intimately linked to the nutrient flow from the diet.
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140
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Jørgensen BB, Findlay AJ, Pellerin A. The Biogeochemical Sulfur Cycle of Marine Sediments. Front Microbiol 2019. [DOI: 10.10.3389/fmicb.2019.00849] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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141
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Spring S, Sorokin DY, Verbarg S, Rohde M, Woyke T, Kyrpides NC. Sulfate-Reducing Bacteria That Produce Exopolymers Thrive in the Calcifying Zone of a Hypersaline Cyanobacterial Mat. Front Microbiol 2019; 10:862. [PMID: 31068923 PMCID: PMC6491731 DOI: 10.3389/fmicb.2019.00862] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 04/04/2019] [Indexed: 12/31/2022] Open
Abstract
Calcifying microbial mats in hypersaline environments are important model systems for the study of the earliest ecosystems on Earth that started to appear more than three billion years ago and have been preserved in the fossil record as laminated lithified structures known as stromatolites. It is believed that sulfate-reducing bacteria play a pivotal role in the lithification process by increasing the saturation index of calcium minerals within the mat. Strain L21-Syr-ABT was isolated from anoxic samples of a several centimeters-thick microbialite-forming cyanobacterial mat of a hypersaline lake on the Kiritimati Atoll (Kiribati, Central Pacific). The novel isolate was assigned to the family Desulfovibrionaceae within the Deltaproteobacteria. Available 16S rRNA-based population surveys obtained from discrete layers of the mat indicate that the occurrence of a species-level clade represented by strain L21-Syr-ABT is restricted to a specific layer of the suboxic zone, which is characterized by the presence of aragonitic spherulites. To elucidate a possible function of this sulfate-reducing bacterium in the mineral formation within the mat a comprehensive phenotypic characterization was combined with the results of a comparative genome analysis. Among the determined traits of strain L21-Syr-ABT, several features were identified that could play a role in the precipitation of calcium carbonate: (i) the potential deacetylation of polysaccharides and consumption of substrates such as lactate and sulfate could mobilize free calcium; (ii) under conditions that favor the utilization of formate and hydrogen, the alkalinity engine within the mat is stimulated, thereby increasing the availability of carbonate; (iii) the production of extracellular polysaccharides could provide nucleation sites for calcium mineralization. In addition, our data suggest the proposal of the novel species and genus Desulfohalovibrio reitneri represented by the type strain L21-Syr-ABT (=DSM 26903T = JCM 18662T).
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Affiliation(s)
- Stefan Spring
- Department Microorganisms, Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Dimitry Y Sorokin
- Winogradsky Institute of Microbiology, Research Centre of Biotechnology, Moscow, Russia.,Department of Biotechnology, Delft University of Technology, Delft, Netherlands
| | - Susanne Verbarg
- Department Services Microorganisms, Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Manfred Rohde
- Central Facility for Microscopy, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Tanja Woyke
- DOE Joint Genome Institute, Walnut Creek, CA, United States
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142
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Jørgensen BB, Findlay AJ, Pellerin A. The Biogeochemical Sulfur Cycle of Marine Sediments. Front Microbiol 2019; 10:849. [PMID: 31105660 PMCID: PMC6492693 DOI: 10.3389/fmicb.2019.00849] [Citation(s) in RCA: 203] [Impact Index Per Article: 40.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 04/02/2019] [Indexed: 11/13/2022] Open
Abstract
Microbial dissimilatory sulfate reduction to sulfide is a predominant terminal pathway of organic matter mineralization in the anoxic seabed. Chemical or microbial oxidation of the produced sulfide establishes a complex network of pathways in the sulfur cycle, leading to intermediate sulfur species and partly back to sulfate. The intermediates include elemental sulfur, polysulfides, thiosulfate, and sulfite, which are all substrates for further microbial oxidation, reduction or disproportionation. New microbiological discoveries, such as long-distance electron transfer through sulfide oxidizing cable bacteria, add to the complexity. Isotope exchange reactions play an important role for the stable isotope geochemistry and for the experimental study of sulfur transformations using radiotracers. Microbially catalyzed processes are partly reversible whereby the back-reaction affects our interpretation of radiotracer experiments and provides a mechanism for isotope fractionation. We here review the progress and current status in our understanding of the sulfur cycle in the seabed with respect to its microbial ecology, biogeochemistry, and isotope geochemistry.
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Affiliation(s)
- Bo Barker Jørgensen
- Department of Bioscience, Center for Geomicrobiology, Aarhus University, Aarhus, Denmark
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143
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Petro C, Zäncker B, Starnawski P, Jochum LM, Ferdelman TG, Jørgensen BB, Røy H, Kjeldsen KU, Schramm A. Marine Deep Biosphere Microbial Communities Assemble in Near-Surface Sediments in Aarhus Bay. Front Microbiol 2019; 10:758. [PMID: 31031732 PMCID: PMC6474314 DOI: 10.3389/fmicb.2019.00758] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 03/26/2019] [Indexed: 11/30/2022] Open
Abstract
Analyses of microbial diversity in marine sediments have identified a core set of taxa unique to the marine deep biosphere. Previous studies have suggested that these specialized communities are shaped by processes in the surface seabed, in particular that their assembly is associated with the transition from the bioturbated upper zone to the nonbioturbated zone below. To test this hypothesis, we performed a fine-scale analysis of the distribution and activity of microbial populations within the upper 50 cm of sediment from Aarhus Bay (Denmark). Sequencing and qPCR were combined to determine the depth distributions of bacterial and archaeal taxa (16S rRNA genes) and sulfate-reducing microorganisms (SRM) (dsrB gene). Mapping of radionuclides throughout the sediment revealed a region of intense bioturbation at 0-6 cm depth. The transition from bioturbated sediment to the subsurface below (7 cm depth) was marked by a shift from dominant surface populations to common deep biosphere taxa (e.g., Chloroflexi and Atribacteria). Changes in community composition occurred in parallel to drops in microbial activity and abundance caused by reduced energy availability below the mixed sediment surface. These results offer direct evidence for the hypothesis that deep subsurface microbial communities present in Aarhus Bay mainly assemble already centimeters below the sediment surface, below the bioturbation zone.
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Affiliation(s)
- Caitlin Petro
- Center for Geomicrobiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Birthe Zäncker
- Center for Geomicrobiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Piotr Starnawski
- Center for Geomicrobiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Lara M. Jochum
- Center for Geomicrobiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Timothy G. Ferdelman
- Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Bo Barker Jørgensen
- Center for Geomicrobiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Hans Røy
- Center for Geomicrobiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Kasper U. Kjeldsen
- Center for Geomicrobiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Andreas Schramm
- Center for Geomicrobiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
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144
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Environmental filtering determines family-level structure of sulfate-reducing microbial communities in subsurface marine sediments. ISME JOURNAL 2019; 13:1920-1932. [PMID: 30894690 DOI: 10.1038/s41396-019-0387-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 01/22/2019] [Accepted: 02/28/2019] [Indexed: 01/09/2023]
Abstract
Recent work has shown that subsurface microbial communities assemble by selective survival of surface community members during sediment burial, but it remains unclear to what extent the compositions of the subsurface communities are a product of their founding population at the sediment surface or of the changing geochemical conditions during burial. Here we investigate this question for communities of sulfate-reducing microorganisms (SRMs). We collected marine sediment samples from the upper 3-5 m at four geochemically contrasting sites in the Skagerrak and Baltic Sea and measured SRM abundance (quantitative PCR of dsrB), metabolic activity (radiotracer rate measurements), and community composition (Illumina sequencing of dsrB amplicons). These data showed that SRM abundance, richness, and phylogenetic clustering as determined by the nearest taxon index peaked below the bioturbation zone and above the depth of sulfate depletion. Minimum cell-specific rates of sulfate reduction did not vary substantially between sites. SRM communities at different sites were best distinguished based on their composition of amplicon sequence variants (ASVs), while communities in different geochemical zones were best distinguished based on their composition of SRM families. This demonstrates environmental filtering of SRM communities in sediment while a site-specific fingerprint of the founding community is retained.
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145
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McKay LJ, Dlakić M, Fields MW, Delmont TO, Eren AM, Jay ZJ, Klingelsmith KB, Rusch DB, Inskeep WP. Co-occurring genomic capacity for anaerobic methane and dissimilatory sulfur metabolisms discovered in the Korarchaeota. Nat Microbiol 2019; 4:614-622. [PMID: 30833730 DOI: 10.1038/s41564-019-0362-4] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 01/07/2019] [Indexed: 11/09/2022]
Abstract
Phylogenetic and geological evidence supports the hypothesis that life on Earth originated in thermal environments and conserved energy through methanogenesis or sulfur reduction. Here we describe two populations of the deeply rooted archaeal phylum Korarchaeota, which were retrieved from the metagenome of a circumneutral, suboxic hot spring that contains high levels of sulfate, sulfide, methane, hydrogen and carbon dioxide. One population is closely related to 'Candidatus Korarchaeum cryptofilum OPF8', while the more abundant korarchaeote, 'Candidatus Methanodesulfokores washburnensis', contains genes that are necessary for anaerobic methane and dissimilatory sulfur metabolisms. Phylogenetic and ancestral reconstruction analyses suggest that methane metabolism originated in the Korarchaeota, whereas genes for dissimilatory sulfite reduction were horizontally transferred to the Korarchaeota from the Firmicutes. Interactions among enzymes involved in both metabolisms could facilitate exergonic, sulfite-dependent, anaerobic oxidation of methane to methanol; alternatively, 'Ca. M. washburnensis' could conduct methanogenesis and sulfur reduction independently. Metabolic reconstruction suggests that 'Ca. M. washburnensis' is a mixotroph, capable of amino acid uptake, assimilation of methane-derived carbon and/or CO2 fixation by archaeal type III-b RuBisCO for scavenging ribose carbon. Our findings link anaerobic methane metabolism and dissimilatory sulfur reduction within a single deeply rooted archaeal population and have implications for the evolution of these traits throughout the Archaea.
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Affiliation(s)
- Luke J McKay
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA. .,Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA.
| | - Mensur Dlakić
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Matthew W Fields
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA.,Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Tom O Delmont
- Department of Medicine, University of Chicago, Chicago, IL, USA.,Genoscope, Évry, France
| | - A Murat Eren
- Department of Medicine, University of Chicago, Chicago, IL, USA.,Josephine Bay Paul Center, Marine Biological Laboratory, Woods Hole, MA, USA
| | - Zackary J Jay
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA
| | | | | | - William P Inskeep
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA. .,Thermal Biology Institute, Montana State University, Bozeman, MT, USA.
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146
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Wang Y, Wegener G, Hou J, Wang F, Xiao X. Expanding anaerobic alkane metabolism in the domain of Archaea. Nat Microbiol 2019; 4:595-602. [PMID: 30833728 DOI: 10.1038/s41564-019-0364-2] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 01/07/2019] [Indexed: 01/03/2023]
Abstract
Methanogenesis and anaerobic methane oxidation through methyl-coenzyme M reductase (MCR) as a key enzyme have been suggested to be basal pathways of archaea1. How widespread MCR-based alkane metabolism is among archaea, where it occurs and how it evolved remain elusive. Here, we performed a global survey of MCR-encoding genomes based on metagenomic data from various environments. Eleven high-quality mcr-containing metagenomic-assembled genomes were obtained belonging to the Archaeoglobi in the Euryarchaeota, Hadesarchaeota and different TACK superphylum archaea, including the Nezhaarchaeota, Korarchaeota and Verstraetearchaeota. Archaeoglobi WYZ-LMO1 and WYZ-LMO3 and Korarchaeota WYZ-LMO9 encode both the (reverse) methanogenesis and the dissimilatory sulfate reduction pathway, suggesting that they have the genomic potential to couple both pathways in individual organisms. The Hadesarchaeota WYZ-LMO4-6 and Archaeoglobi JdFR-42 encode highly divergent MCRs, enzymes that may enable them to thrive on non-methane alkanes. The occurrence of mcr genes in different archaeal phyla indicates that MCR-based alkane metabolism is common in the domain of Archaea.
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Affiliation(s)
- Yinzhao Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Gunter Wegener
- Max Planck Institute for Marine Microbiology, Bremen, Germany.,MARUM, Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany
| | - Jialin Hou
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Fengping Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
| | - Xiang Xiao
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China. .,State Key Laboratory of Ocean Engineering, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, China.
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147
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Contrasting Pathways for Anaerobic Methane Oxidation in Gulf of Mexico Cold Seep Sediments. mSystems 2019; 4:mSystems00091-18. [PMID: 30834326 PMCID: PMC6392090 DOI: 10.1128/msystems.00091-18] [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] [Received: 06/08/2018] [Accepted: 02/04/2019] [Indexed: 12/15/2022] Open
Abstract
Cold seep sediments are complex and widespread marine ecosystems emitting large amounts of methane, a potent greenhouse gas, and other hydrocarbons. Within these sediments, microbial communities play crucial roles in production and degradation of hydrocarbons, modulating oil and gas emissions to seawater. Despite this ecological importance, our understanding of microbial functions and methane oxidation pathways in cold seep ecosystems is poor. Based on gene expression profiling of environmental seep sediment samples, the present work showed that (i) the composition of the emitted fluids shapes the microbial community in general and the anaerobic methanotroph community specifically and (ii) AOM by ANME-2 in this seep may be coupled to sulfate reduction by Deltaproteobacteria by electron transfer through multiheme cytochromes, whereas AOM by ANME-1 lineages in this seep may involve a different, bacterium-independent pathway, coupling methane oxidation to elemental sulfur/polysulfide reduction. Gulf of Mexico sediments harbor numerous hydrocarbon seeps associated with high sedimentation rates and thermal maturation of organic matter. These ecosystems host abundant and diverse microbial communities that directly or indirectly metabolize components of the emitted fluid. To investigate microbial function and activities in these ecosystems, metabolic potential (metagenomic) and gene expression (metatranscriptomic) analyses of two cold seep areas of the Gulf of Mexico were carried out. Seeps emitting biogenic methane harbored microbial communities dominated by archaeal anaerobic methane oxidizers of phylogenetic group 1 (ANME-1), whereas seeps producing fluids containing a complex mixture of thermogenic hydrocarbons were dominated by ANME-2 lineages. Metatranscriptome measurements in both communities indicated high levels of expression of genes for methane metabolism despite their distinct microbial communities and hydrocarbon composition. In contrast, the transcription level of sulfur cycle genes was quite different. In the thermogenic seep community, high levels of transcripts indicative of syntrophic anaerobic oxidation of methane (AOM) coupled to sulfate reduction were detected. This syntrophic partnership between the dominant ANME-2 and sulfate reducers potentially involves direct electron transfer through multiheme cytochromes. In the biogenic methane seep, genes from an ANME-1 lineage that are potentially involved in polysulfide reduction were highly expressed, suggesting a novel bacterium-independent anaerobic methane oxidation pathway coupled to polysulfide reduction. The observed divergence in AOM activities provides a new model for bacterium-independent AOM and emphasizes the variation that exists in AOM pathways between different ANME lineages. IMPORTANCE Cold seep sediments are complex and widespread marine ecosystems emitting large amounts of methane, a potent greenhouse gas, and other hydrocarbons. Within these sediments, microbial communities play crucial roles in production and degradation of hydrocarbons, modulating oil and gas emissions to seawater. Despite this ecological importance, our understanding of microbial functions and methane oxidation pathways in cold seep ecosystems is poor. Based on gene expression profiling of environmental seep sediment samples, the present work showed that (i) the composition of the emitted fluids shapes the microbial community in general and the anaerobic methanotroph community specifically and (ii) AOM by ANME-2 in this seep may be coupled to sulfate reduction by Deltaproteobacteria by electron transfer through multiheme cytochromes, whereas AOM by ANME-1 lineages in this seep may involve a different, bacterium-independent pathway, coupling methane oxidation to elemental sulfur/polysulfide reduction.
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148
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Quantifying population-specific growth in benthic bacterial communities under low oxygen using H 218O. ISME JOURNAL 2019; 13:1546-1559. [PMID: 30783213 PMCID: PMC6776007 DOI: 10.1038/s41396-019-0373-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 01/26/2019] [Accepted: 01/31/2019] [Indexed: 01/09/2023]
Abstract
The benthos in estuarine environments often experiences periods of regularly occurring hypoxic and anoxic conditions, dramatically impacting biogeochemical cycles. How oxygen depletion affects the growth of specific uncultivated microbial populations within these diverse benthic communities, however, remains poorly understood. Here, we applied H218O quantitative stable isotope probing (qSIP) in order to quantify the growth of diverse, uncultured bacterial populations in response to low oxygen concentrations in estuarine sediments. Over the course of 7- and 28-day incubations with redox conditions spanning from hypoxia to euxinia (sulfidic), 18O labeling of bacterial populations exhibited different patterns consistent with micro-aerophilic, anaerobic, facultative anaerobic, and aerotolerant anaerobic growth. 18O-labeled populations displaying anaerobic growth had a significantly non-random phylogenetic distribution, exhibited by numerous clades currently lacking cultured representatives within the Planctomycetes, Actinobacteria, Latescibacteria, Verrucomicrobia, and Acidobacteria. Genes encoding the beta-subunit of the dissimilatory sulfate reductase (dsrB) became 18O labeled only during euxinic conditions. Sequencing of these 18O-labeled dsrB genes showed that Acidobacteria were the dominant group of growing sulfate-reducing bacteria, highlighting their importance for sulfur cycling in estuarine sediments. Our findings provide the first experimental constraints on the redox conditions underlying increased growth in several groups of "microbial dark matter", validating hypotheses put forth by earlier metagenomic studies.
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149
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Wörner S, Pester M. The Active Sulfate-Reducing Microbial Community in Littoral Sediment of Oligotrophic Lake Constance. Front Microbiol 2019; 10:247. [PMID: 30814991 PMCID: PMC6381063 DOI: 10.3389/fmicb.2019.00247] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 01/30/2019] [Indexed: 11/16/2022] Open
Abstract
Active sulfate-reducing microorganisms (SRM) in freshwater sediments are under-examined, despite the well-documented cryptic sulfur cycle occurring in these low-sulfate habitats. In Lake Constance sediment, sulfate reduction rates of up to 1,800 nmol cm-3 day-1 were previously measured. To characterize its SRM community, we used a tripartite amplicon sequencing approach based on 16S rRNA genes, 16S rRNA, and dsrB transcripts (encoding the beta subunit of dissimilatory sulfite reductase). We followed the respective amplicon dynamics in four anoxic microcosm setups supplemented either with (i) chitin and sulfate, (ii) sulfate only, (iii) chitin only, or (iv) no amendment. Chitin was used as a general substrate for the whole carbon degradation chain. Sulfate turnover in sulfate-supplemented microcosms ranged from 38 to 955 nmol day-1 (g sediment f. wt.)-1 and was paralleled by a decrease of 90–100% in methanogenesis as compared to the respective methanogenic controls. In the initial sediment, relative abundances of recognized SRM lineages accounted for 3.1 and 4.4% of all bacterial 16S rRNA gene and 16S rRNA sequences, respectively. When normalized against the 1.4 × 108 total prokaryotic 16S rRNA gene copies as determined by qPCR and taking multiple rrn operons per genome into account, this resulted in approximately 105–106 SRM cells (g sediment f. wt.)-1. The three amplicon approaches jointly identified Desulfobacteraceae and Syntrophobacteraceae as the numerically dominant and transcriptionally most active SRM in the initial sediment. This was corroborated in the time course analyses of sulfate-consuming sediment microcosms irrespective of chitin amendment. Uncultured dsrAB family-level lineages constituted in sum only 1.9% of all dsrB transcripts, with uncultured lineage 5 and 6 being transcriptionally most active. Our study is the first holistic molecular approach to quantify and characterize active SRM including uncultured dsrAB lineages not only in Lake Constance but for lake sediments in general.
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Affiliation(s)
- Susanne Wörner
- Department of Biology, University of Konstanz, Konstanz, Germany.,Leibniz Institute DSMZ - German Collection of Microorganisms and Cell cultures, Braunschweig, Germany
| | - Michael Pester
- Department of Biology, University of Konstanz, Konstanz, Germany.,Leibniz Institute DSMZ - German Collection of Microorganisms and Cell cultures, Braunschweig, Germany.,Institute for Microbiology, Technical University of Braunschweig, Braunschweig, Germany
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150
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Wang R, Xu S, Jiang C, Zhang Y, Bai N, Zhuang G, Bai Z, Zhuang X. Impacts of Human Activities on the Composition and Abundance of Sulfate-Reducing and Sulfur-Oxidizing Microorganisms in Polluted River Sediments. Front Microbiol 2019; 10:231. [PMID: 30809217 PMCID: PMC6379298 DOI: 10.3389/fmicb.2019.00231] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 01/28/2019] [Indexed: 11/30/2022] Open
Abstract
Water system degradation has a severe impact on daily life, especially in developing countries. However, microbial changes associated with this degradation, especially changes in microbes related to sulfur (S) cycling, are poorly understood. In this study, the abundance, structure, and diversity of sulfate-reducing microorganisms (SRM) and sulfur-oxidizing microorganisms (SOM) in the sediments from the Ziya River Basin, which is polluted by various human interventions (urban and agricultural activities), were investigated. Quantitative real-time PCR showed that the S cycling-related (SCR) genes (dsrB and soxB) were significantly elevated, reaching 2.60 × 107 and 1.81 × 108 copies per gram of dry sediment, respectively, in the region polluted by human urban activities (RU), and the ratio of dsrB to soxB abundance was significantly elevated in the region polluted by human agricultural activities (RA) compared with those in the protected wildlife reserve (RP), indicating that the mechanisms underlying water system degradation differ between RU and RA. Based on a 16S rRNA gene analysis, human interventions had substantial effects on microbial communities, particularly for microbes involved in S cycling. Some SCR genera (i.e., Desulfatiglans and Geothermobacter) were enriched in the sediments from both RA and RU, while others (i.e., Desulfofustis and Desulfonatronobacter) were only enriched in the sediments from RA. A redundancy analysis indicated that NH4+-N and total organic carbon significantly influenced the abundance of SRM and SOM, and sulfate significantly influenced only the abundance of SRM. A network analysis showed high correlation between SCR microorganisms and other microbial groups for both RU and RA, including those involved in carbon and metal cycling. These findings indicated the different effects of different human interventions on the microbial community composition and water quality degradation.
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Affiliation(s)
- Rui Wang
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Shengjun Xu
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Cancan Jiang
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Yang Zhang
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Na Bai
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.,School of Safety and Environmental Engineering, Capital University of Economics and Business, Beijing, China
| | - Guoqiang Zhuang
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Zhihui Bai
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Xuliang Zhuang
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
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