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Colman DR, Keller LM, Arteaga-Pozo E, Andrade-Barahona E, St Clair B, Shoemaker A, Cox A, Boyd ES. Covariation of hot spring geochemistry with microbial genomic diversity, function, and evolution. Nat Commun 2024; 15:7506. [PMID: 39209850 PMCID: PMC11362583 DOI: 10.1038/s41467-024-51841-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 08/20/2024] [Indexed: 09/04/2024] Open
Abstract
The geosphere and the microbial biosphere have co-evolved for ~3.8 Ga, with many lines of evidence suggesting a hydrothermal habitat for life's origin. However, the extent that contemporary thermophiles and their hydrothermal habitats reflect those that likely existed on early Earth remains unknown. To address this knowledge gap, 64 geochemical analytes were measured and 1022 metagenome-assembled-genomes (MAGs) were generated from 34 chemosynthetic high-temperature springs in Yellowstone National Park and analysed alongside 444 MAGs from 35 published metagenomes. We used these data to evaluate co-variation in MAG taxonomy, metabolism, and phylogeny as a function of hot spring geochemistry. We found that cohorts of MAGs and their functions are discretely distributed across pH gradients that reflect different geochemical provinces. Acidic or circumneutral/alkaline springs harbor MAGs that branched later and are enriched in sulfur- and arsenic-based O2-dependent metabolic pathways that are inconsistent with early Earth conditions. In contrast, moderately acidic springs sourced by volcanic gas harbor earlier-branching MAGs that are enriched in anaerobic, gas-dependent metabolisms (e.g. H2, CO2, CH4 metabolism) that have been hypothesized to support early microbial life. Our results provide insight into the influence of redox state in the eco-evolutionary feedbacks between thermophiles and their habitats and suggest moderately acidic springs as early Earth analogs.
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Affiliation(s)
- Daniel R Colman
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA.
| | - Lisa M Keller
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Emilia Arteaga-Pozo
- Department of Chemistry and Geochemistry, Montana Technological University, Butte, MT, USA
| | - Eva Andrade-Barahona
- Department of Chemistry and Geochemistry, Montana Technological University, Butte, MT, USA
| | - Brian St Clair
- Department of Chemistry and Geochemistry, Montana Technological University, Butte, MT, USA
| | - Anna Shoemaker
- Department of Earth Sciences, Montana State University, Bozeman, MT, USA
| | - Alysia Cox
- Department of Chemistry and Geochemistry, Montana Technological University, Butte, MT, USA
| | - Eric S Boyd
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA.
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Colman DR, Veach A, Stefánsson A, Wurch L, Belisle BS, Podar PT, Yang Z, Klingeman D, Senba K, Murakami KS, Kristjánsson JK, Björnsdóttir SH, Boyd ES, Podar M. Tectonic and geological setting influence hot spring microbiology. Environ Microbiol 2023; 25:2481-2497. [PMID: 37553090 DOI: 10.1111/1462-2920.16472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 07/12/2023] [Indexed: 08/10/2023]
Abstract
Hydrothermal systems form at divergent and convergent boundaries of lithospheric plates and within plates due to weakened crust and mantle plumes, playing host to diverse microbial ecosystems. Little is known of how differences in tectonic setting influence the geochemical and microbial compositions of these hydrothermal ecosystems. Here, coordinated geochemical and microbial community analyses were conducted on 87 high-temperature (>65°C) water and sediment samples from hot springs in Yellowstone National Park, Wyoming, USA (n = 41; mantle plume setting), Iceland (n = 41, divergent boundary), and Japan (n = 5; convergent boundary). Region-specific variation in geochemistry and sediment-associated 16S rRNA gene amplicon sequence variant (ASV) composition was observed, with 16S rRNA gene assemblages being nearly completely distinguished by region and pH being the most explanatory parameter within regions. Several low abundance ASVs exhibited cosmopolitan distributions across regions, while most high-abundance ASVs were only identified in specific regions. The presence of some cosmopolitan ASVs across regions argues against dispersal limitation primarily shaping the distribution of taxa among regions. Rather, the results point to local tectonic and geologic characteristics shaping the geochemistry of continental hydrothermal systems that then select for distinct microbial assemblages. These results provide new insights into the co-evolution of hydrothermal systems and their microbial communities.
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Affiliation(s)
- Daniel R Colman
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, Montana, USA
| | - Allison Veach
- Department of Integrative Biology, University of Texas at San Antonio, San Antonio, Texas, USA
| | - Andri Stefánsson
- Institute of Earth Sciences, University of Iceland, Reykjavik, Iceland
| | - Louie Wurch
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- Department of Biology, James Madison University, Harrisonburg, Virginia, USA
| | - B Shafer Belisle
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Peter T Podar
- School of Engineering, Vanderbilt University, Nashville, Tennessee, USA
| | - Zamin Yang
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Dawn Klingeman
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Kazuyo Senba
- Department of Microbiology, Beppu University, Beppu, Oita, Japan
| | - Katsuhiko S Murakami
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, State College, Pennsylvania, USA
| | | | | | - Eric S Boyd
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, Montana, USA
| | - Mircea Podar
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
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Murali R, Gennis RB, Hemp J. Evolution of the cytochrome bd oxygen reductase superfamily and the function of CydAA' in Archaea. THE ISME JOURNAL 2021; 15:3534-3548. [PMID: 34145390 PMCID: PMC8630170 DOI: 10.1038/s41396-021-01019-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 05/06/2021] [Accepted: 05/17/2021] [Indexed: 02/05/2023]
Abstract
Cytochrome bd-type oxygen reductases (cytbd) belong to one of three enzyme superfamilies that catalyze oxygen reduction to water. They are widely distributed in Bacteria and Archaea, but the full extent of their biochemical diversity is unknown. Here we used phylogenomics to identify three families and several subfamilies within the cytbd superfamily. The core architecture shared by all members of the superfamily consists of four transmembrane helices that bind two active site hemes, which are responsible for oxygen reduction. While previously characterized cytochrome bd-type oxygen reductases use quinol as an electron donor to reduce oxygen, sequence analysis shows that only one of the identified families has a conserved quinol binding site. The other families are missing this feature, suggesting that they use an alternative electron donor. Multiple gene duplication events were identified within the superfamily, resulting in significant evolutionary and structural diversity. The CydAA' cytbd, found exclusively in Archaea, is formed by the co-association of two superfamily paralogs. We heterologously expressed CydAA' from Caldivirga maquilingensis and demonstrated that it performs oxygen reduction with quinol as an electron donor. Strikingly, CydAA' is the first isoform of cytbd containing only b-type hemes shown to be active when isolated from membranes, demonstrating that oxygen reductase activity in this superfamily is not dependent on heme d.
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Affiliation(s)
- Ranjani Murali
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
| | - Robert B Gennis
- Department of Biochemistry, University of Illinois, Urbana-Champaign, Urbana, IL, USA
| | - James Hemp
- The Metrodora Institute, Salt Lake City, UT, USA.
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Ecological Dichotomies Arise in Microbial Communities Due to Mixing of Deep Hydrothermal Waters and Atmospheric Gas in a Circumneutral Hot Spring. Appl Environ Microbiol 2021; 87:e0159821. [PMID: 34586901 PMCID: PMC8579995 DOI: 10.1128/aem.01598-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Little is known of how the confluence of subsurface and surface processes influences the assembly and habitability of hydrothermal ecosystems. To address this knowledge gap, the geochemical and microbial composition of a high-temperature, circumneutral hot spring in Yellowstone National Park was examined to identify the sources of solutes and their effect on the ecology of microbial inhabitants. Metagenomic analysis showed that populations comprising planktonic and sediment communities are archaeal dominated, are dependent on chemical energy (chemosynthetic), share little overlap in their taxonomic composition, and are differentiated by their inferred use of/tolerance to oxygen and mode of carbon metabolism. The planktonic community is dominated by putative aerobic/aerotolerant autotrophs, while the taxonomic composition of the sediment community is more evenly distributed and comprised of anaerobic heterotrophs. These observations are interpreted to reflect sourcing of the spring by anoxic, organic carbon-limited subsurface hydrothermal fluids and ingassing of atmospheric oxygen that selects for aerobic/aerotolerant organisms that have autotrophic capabilities in the water column. Autotrophy and consumption of oxygen by the planktonic community may influence the assembly of the anaerobic and heterotrophic sediment community. Support for this inference comes from higher estimated rates of genome replication in planktonic populations than sediment populations, indicating faster growth in planktonic populations. Collectively, these observations provide new insight into how mixing of subsurface waters and atmospheric oxygen create dichotomy in the ecology of hot spring communities and suggest that planktonic and sediment communities may have been less differentiated taxonomically and functionally prior to the rise of oxygen at ∼2.4 billion years ago (Gya). IMPORTANCE Understanding the source and availability of energy capable of supporting life in hydrothermal environments is central to predicting the ecology of microbial life on early Earth when volcanic activity was more widespread. Little is known of the substrates supporting microbial life in circumneutral to alkaline springs, despite their relevance to early Earth habitats. Using metagenomic and informatics approaches, water column and sediment habitats in a representative circumneutral hot spring in Yellowstone were shown to be dichotomous, with the former largely hosting aerobic/aerotolerant autotrophs and the latter primarily hosting anaerobic heterotrophs. This dichotomy is attributed to influx of atmospheric oxygen into anoxic deep hydrothermal spring waters. These results indicate that the ecology of microorganisms in circumneutral alkaline springs sourced by deep hydrothermal fluids was different prior to the rise of atmospheric oxygen ∼2.4 Gya, with planktonic and sediment communities likely to be less differentiated than contemporary circumneutral hot springs.
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Li YX, Rao YZ, Qi YL, Qu YN, Chen YT, Jiao JY, Shu WS, Jiang H, Hedlund BP, Hua ZS, Li WJ. Deciphering Symbiotic Interactions of " Candidatus Aenigmarchaeota" with Inferred Horizontal Gene Transfers and Co-occurrence Networks. mSystems 2021; 6:e0060621. [PMID: 34313464 PMCID: PMC8407114 DOI: 10.1128/msystems.00606-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 07/09/2021] [Indexed: 11/30/2022] Open
Abstract
"Candidatus Aenigmarchaeota" ("Ca. Aenigmarchaeota") represents one of the earliest proposed evolutionary branches within the Diapherotrites, Parvarchaeota, Aenigmarchaeota, Nanoarchaeota, and Nanohaloarchaeota (DPANN) superphylum. However, their ecological roles and potential host-symbiont interactions are still poorly understood. Here, eight metagenome-assembled genomes (MAGs) were reconstructed from hot spring ecosystems, and further in-depth comparative and evolutionary genomic analyses were conducted on these MAGs and other genomes downloaded from public databases. Although with limited metabolic capacities, we reported that "Ca. Aenigmarchaeota" in thermal environments harbor more genes related to carbohydrate metabolism than "Ca. Aenigmarchaeota" in nonthermal environments. Evolutionary analyses suggested that members from the Thaumarchaeota, Aigarchaeota, Crenarchaeota, and Korarchaeota (TACK) superphylum and Euryarchaeota contribute substantially to the niche expansion of "Ca. Aenigmarchaeota" via horizontal gene transfer (HGT), especially genes related to virus defense and stress responses. Based on co-occurrence network results and recent genetic exchanges among community members, we conjectured that "Ca. Aenigmarchaeota" may be symbionts associated with one MAG affiliated with the genus Pyrobaculum, though host specificity might be wide and variable across different "Ca. Aenigmarchaeota" organisms. This study provides significant insight into possible DPANN-host interactions and ecological roles of "Ca. Aenigmarchaeota." IMPORTANCE Recent advances in sequencing technology promoted the blowout discovery of super tiny microbes in the Diapherotrites, Parvarchaeota, Aenigmarchaeota, Nanoarchaeota, and Nanohaloarchaeota (DPANN) superphylum. However, the unculturable properties of the majority of microbes impeded our investigation of their behavior and symbiotic lifestyle in the corresponding community. By integrating horizontal gene transfer (HGT) detection and co-occurrence network analysis on "Candidatus Aenigmarchaeota" ("Ca. Aenigmarchaeota"), we made one of the first attempts to infer their putative interaction partners and further decipher the potential functional and genetic interactions between the symbionts. We revealed that HGTs contributed by members from the Thaumarchaeota, Aigarchaeota, Crenarchaeota, and Korarchaeota (TACK) superphylum and Euryarchaeota conferred "Ca. Aenigmarchaeota" with the ability to survive under different environmental stresses, such as virus infection, high temperature, and oxidative stress. This study demonstrates that the interaction partners might be inferable by applying informatics analyses on metagenomic sequencing data.
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Affiliation(s)
- Yu-Xian Li
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, People’s Republic of China
| | - Yang-Zhi Rao
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, People’s Republic of China
| | - Yan-Ling Qi
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, People’s Republic of China
| | - Yan-Ni Qu
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, People’s Republic of China
| | - Ya-Ting Chen
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, People’s Republic of China
| | - Jian-Yu Jiao
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, People’s Republic of China
| | - Wen-Sheng Shu
- School of Life Sciences, South China Normal University, Guangzhou, People’s Republic of China
| | - Hongchen Jiang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, People’s Republic of China
| | - Brian P. Hedlund
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, Nevada, USA
- Nevada Institute of Personalized Medicine, University of Nevada Las Vegas, Las Vegas, Nevada, USA
| | - Zheng-Shuang Hua
- Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei, People’s Republic of China
| | - Wen-Jun Li
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, People’s Republic of China
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, People’s Republic of China
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6
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Zayulina KS, Elcheninov AG, Toshchakov SV, Kochetkova TV, Novikov AA, Blamey JM, Kublanov IV. Novel hyperthermophilic crenarchaeon Infirmifilum lucidum gen. nov. sp. nov., reclassification of Thermofilum uzonense as Infirmifilum uzonense comb. nov. and assignment of the family Thermofilaceae to the order Thermofilales ord. nov. Syst Appl Microbiol 2021; 44:126230. [PMID: 34293647 DOI: 10.1016/j.syapm.2021.126230] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 06/25/2021] [Accepted: 07/02/2021] [Indexed: 02/01/2023]
Abstract
A novel hyperthermophilic crenarchaeon, strain 3507LTT, was isolated from a terrestrial hot spring near Tinguiririca volcano, Chile. Cells were non-motile thin, slightly curved filamentous rods. It grew at 73-93 °C and pH range of 5 to 7.5 with an optimum at 85 °C and pH 6.0-6.7. The presence of culture broth filtrate of another hyperthemophilic archaeon as well as yeast extract was obligatory for growth of the novel isolate. Strain 3507LTT is an anaerobic chemoorganoheterotroph, fermenting monosaccharides, disaccharides and polysaccharides (lichenan, starch, xanthan gum, xyloglucan, alpha-cellulose and amorphous cellulose). No growth stimulation was detected when nitrate, thiosulfate, selenate or elemental sulfur were added as the electron acceptors. The complete genome of strain 3507LTT consisted of a single circular chromosome with size of 1.63 Mbp. The DNA G+C content was 53.9%. According to the 16S rRNA gene sequence as well as conserved protein sequences phylogenetic analyses, strain 3507LTT together with Thermofilum uzonense formed a separate cluster within a Thermofilaceae family (Thermoproteales/Thermoprotei/Crenarchaeota). Based on phenotypic characteristics, phylogeny as well as AAI comparisons, a novel genus and species Infirmifilum lucidum strain 3507LTT (=VKM B-3376T = KCTC 15797T) gen. nov. sp. nov. was proposed. Its closest relative, Thermofilum uzonense strain 1807-2T should be reclassified as Infirmifilum uzonense strain 1807-2T comb. nov. Finally, based on phylogenomic and comparative genome analyses of representatives of Thermofilaceae family and other representatives of Thermoproteales order, a proposal of transfer of the family Thermofilaceae into a separate order Thermofilales ord. nov. was made.
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Affiliation(s)
- Kseniya S Zayulina
- Winogradsky Institute of Microbiology, Research Center of Biotechnology RAS, 7/2 Prospekt 60-letiya Oktyabrya, 117312 Moscow, Russia.
| | - Alexander G Elcheninov
- Winogradsky Institute of Microbiology, Research Center of Biotechnology RAS, 7/2 Prospekt 60-letiya Oktyabrya, 117312 Moscow, Russia
| | - Stepan V Toshchakov
- Winogradsky Institute of Microbiology, Research Center of Biotechnology RAS, 7/2 Prospekt 60-letiya Oktyabrya, 117312 Moscow, Russia
| | - Tatiana V Kochetkova
- Winogradsky Institute of Microbiology, Research Center of Biotechnology RAS, 7/2 Prospekt 60-letiya Oktyabrya, 117312 Moscow, Russia
| | - Andrei A Novikov
- Gubkin University, 65-1, Leninsky prospect, 119991 Moscow, Russia
| | - Jenny M Blamey
- Fundacion Biociencia, Jose Domingo Cañas, 2280 Ñuñoa, Santiago, Chile; Facultad de Química y Biología, Universidad de Santiago de Chile, Alameda 3363, Estación Central, Santiago, Chile
| | - Ilya V Kublanov
- Winogradsky Institute of Microbiology, Research Center of Biotechnology RAS, 7/2 Prospekt 60-letiya Oktyabrya, 117312 Moscow, Russia
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Microbe-Mineral Interaction and Novel Proteins for Iron Oxide Mineral Reduction in the Hyperthermophilic Crenarchaeon Pyrodictium delaneyi. Appl Environ Microbiol 2021; 87:AEM.02330-20. [PMID: 33419739 PMCID: PMC8105010 DOI: 10.1128/aem.02330-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 12/17/2020] [Indexed: 11/24/2022] Open
Abstract
Understanding iron reduction in the hyperthermophilic crenarchaeon Pyrodictium delaneyi provides insight into the diversity of mechanisms used for this process and its potential impact in geothermal environments. The ability of P. delaneyi to reduce Fe(III) oxide minerals through direct contact potentially using a novel cytochrome respiratory complex and a membrane-bound molybdopterin respiratory complex sets iron reduction in this organism apart from previously described iron reduction processes. Dissimilatory iron reduction by hyperthermophilic archaea occurs in many geothermal environments and generally relies on microbe-mineral interactions that transform various iron oxide minerals. In this study, the physiology of dissimilatory iron and nitrate reduction was examined in the hyperthermophilic crenarchaeon type strain Pyrodictium delaneyi Su06. Iron barrier experiments showed that P. delaneyi required direct contact with the Fe(III) oxide mineral ferrihydrite for reduction. The separate addition of an exogenous electron shuttle (anthraquinone-2,6-disulfonate), a metal chelator (nitrilotriacetic acid), and 75% spent cell-free supernatant did not stimulate growth with or without the barrier. Protein electrophoresis showed that the c-type cytochrome and general protein compositions of P. delaneyi changed when grown on ferrihydrite relative to nitrate. Differential proteomic analyses using tandem mass tagged protein fragments and mass spectrometry detected 660 proteins and differential production of 127 proteins. Among these, two putative membrane-bound molybdopterin-dependent oxidoreductase complexes increased in relative abundance 60- to 3,000-fold and 50- to 100-fold in cells grown on iron oxide. A putative 8-heme c-type cytochrome was 60-fold more abundant in iron-grown cells and was unique to the Pyrodictiaceae. There was also a >14,700-fold increase in a membrane transport protein in iron-grown cells. For flagellin proteins and a putative nitrate reductase, there were no changes in abundance, but a membrane nitric oxide reductase was more abundant on nitrate. These data help to elucidate the mechanisms by which hyperthermophilic crenarchaea generate energy and transfer electrons across the membrane to iron oxide minerals. IMPORTANCE Understanding iron reduction in the hyperthermophilic crenarchaeon Pyrodictium delaneyi provides insight into the diversity of mechanisms used for this process and its potential impact in geothermal environments. The ability of P. delaneyi to reduce Fe(III) oxide minerals through direct contact potentially using a novel cytochrome respiratory complex and a membrane-bound molybdopterin respiratory complex sets iron reduction in this organism apart from previously described iron reduction processes. A model is presented where obligatory H2 oxidation on the membrane coupled with electron transport and either Fe(III) oxide or nitrate reduction leads to the generation of a proton motive force and energy generation by oxidative phosphorylation. However, P. delaneyi cannot fix CO2 and relies on organic compounds from its environment for biosynthesis.
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Activity-based cell sorting reveals responses of uncultured archaea and bacteria to substrate amendment. ISME JOURNAL 2020; 14:2851-2861. [PMID: 32887944 PMCID: PMC7784905 DOI: 10.1038/s41396-020-00749-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 07/30/2020] [Accepted: 08/12/2020] [Indexed: 12/13/2022]
Abstract
Metagenomic studies have revolutionized our understanding of the metabolic potential of uncultured microorganisms in various ecosystems. However, many of these genomic predictions have yet to be experimentally tested, and the functional expression of genomic potential often remains unaddressed. In order to obtain a more thorough understanding of cell physiology, novel techniques capable of testing microbial metabolism under close to in situ conditions must be developed. Here, we provide a benchmark study to demonstrate that bioorthogonal non-canonical amino acid tagging (BONCAT) in combination with fluorescence-activated cell sorting (FACS) and 16S rRNA gene sequencing can be used to identify anabolically active members of a microbial community incubated in the presence of various growth substrates or under changing physicochemical conditions. We applied this approach to a hot spring sediment microbiome from Yellowstone National Park (Wyoming, USA) and identified several microbes that changed their activity levels in response to substrate addition, including uncultured members of the phyla Thaumarchaeota, Acidobacteria, and Fervidibacteria. Because shifts in activity in response to substrate amendment or headspace changes are indicative of microbial preferences for particular growth conditions, results from this and future BONCAT-FACS studies could inform the development of cultivation media to specifically enrich uncultured microbes. Most importantly, BONCAT-FACS is capable of providing information on the physiology of uncultured organisms at as close to in situ conditions as experimentally possible.
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Han YH, Yin DX, Jia MR, Wang SS, Chen Y, Rathinasabapathi B, Chen DL, Ma LQ. Arsenic-resistance mechanisms in bacterium Leclercia adecarboxylata strain As3-1: Biochemical and genomic analyses. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 690:1178-1189. [PMID: 31470481 DOI: 10.1016/j.scitotenv.2019.07.098] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 07/06/2019] [Accepted: 07/07/2019] [Indexed: 06/10/2023]
Abstract
Microbial arsenic transformation is important in As biogeochemical cycles in the environment. In this study, a new As-resistant bacterial strain Leclercia adecarboxylata As3-1 was isolated and its associated mechanisms in As resistance and detoxification were evaluated based on genome sequencing and gene annotations. After subjecting strain As3-1 to medium containing arsenate (AsV), AsV reduction occurred and an AsV-enhanced bacterial growth was observed. Strain As3-1 lacked arsenite (AsIII) oxidation ability and displayed lower AsIII resistance than AsV, probably due to its higher AsIII accumulation. Polymerase chain reaction and phylogenetic analysis showed that strain As3-1 harbored a typical AsV reductase gene (arsC) on the plasmids. Genome sequencing and gene annotations identified four operons phoUpstBACS, arsHRBC, arsCRDABC and ttrRSBCA, with 8 additional genes outside the operons that might have involved in As resistance and detoxification in strain As3-1. These included 5 arsC genes explaining why strain As3-1 tolerated high AsV concentrations. Besides ArsC, TtrB, TtrC and TtrA proteins could also be involved in AsV reduction and consequent energy acquisition for bacterial growth. Our data provided a new example of diverse As-regulating systems and AsV-enhanced growth without ArrA in bacteria. The information helps to understand the role of As in selecting microbial systems that can transform and utilize As.
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Affiliation(s)
- Yong-He Han
- Quangang Petrochemical Research Institute, Fujian Normal University, Quanzhou, Fujian 362801, China; College of Environmental Science and Engineering, Fujian Normal University, Fuzhou, Fujian 350007, China; Fujian Key Laboratory of Pollution Control and Resource Reuse, Fuzhou 350007, China
| | - Dai-Xia Yin
- School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Meng-Ru Jia
- School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Shan-Shan Wang
- Quangang Petrochemical Research Institute, Fujian Normal University, Quanzhou, Fujian 362801, China
| | - Yanshan Chen
- School of the Environment, Nanjing Normal University, Nanjing, Jiangsu 210023, China
| | - Bala Rathinasabapathi
- Horticultural Sciences Department, University of Florida, Gainesville, FL 32611, United States
| | - Deng-Long Chen
- Quangang Petrochemical Research Institute, Fujian Normal University, Quanzhou, Fujian 362801, China; Innovative Center for Eco-Friendly Polymeric Materials, Quanzhou, Fujian 362801, China.
| | - Lena Q Ma
- College of Environmental Science and Engineering, Fujian Normal University, Fuzhou, Fujian 350007, China; Soil and Water Sciences Department, University of Florida, Gainesville, FL 32611, United States.
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10
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Lindsay MR, Amenabar MJ, Fecteau KM, Debes RV, Fernandes Martins MC, Fristad KE, Xu H, Hoehler TM, Shock EL, Boyd ES. Subsurface processes influence oxidant availability and chemoautotrophic hydrogen metabolism in Yellowstone hot springs. GEOBIOLOGY 2018; 16:674-692. [PMID: 30035368 DOI: 10.1111/gbi.12308] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 04/15/2018] [Accepted: 06/20/2018] [Indexed: 06/08/2023]
Abstract
The geochemistry of hot springs and the availability of oxidants capable of supporting microbial metabolisms are influenced by subsurface processes including the separation of hydrothermal fluids into vapor and liquid phases. Here, we characterized the influence of geochemical variation and oxidant availability on the abundance, composition, and activity of hydrogen (H2 )-dependent chemoautotrophs along the outflow channels of two-paired hot springs in Yellowstone National Park. The hydrothermal fluid at Roadside East (RSE; 82.4°C, pH 3.0) is acidic due to vapor-phase input while the fluid at Roadside West (RSW; 68.1°C, pH 7.0) is circumneutral due to liquid-phase input. Most chemotrophic communities exhibited net rates of H2 oxidation, consistent with H2 support of primary productivity, with one chemotrophic community exhibiting a net rate of H2 production. Abundant H2 -oxidizing chemoautotrophs were supported by reduction in oxygen, elemental sulfur, sulfate, and nitrate in RSW and oxygen and ferric iron in RSE; O2 utilizing hydrogenotrophs increased in abundance down both outflow channels. Sequencing of 16S rRNA transcripts or genes from native sediments and dilution series incubations, respectively, suggests that members of the archaeal orders Sulfolobales, Desulfurococcales, and Thermoproteales are likely responsible for H2 oxidation in RSE, whereas members of the bacterial order Thermoflexales and the archaeal order Thermoproteales are likely responsible for H2 oxidation in RSW. These observations suggest that subsurface processes strongly influence spring chemistry and oxidant availability, which in turn select for unique assemblages of H2 oxidizing microorganisms. Therefore, these data point to the role of oxidant availability in shaping the ecology and evolution of hydrogenotrophic organisms.
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Affiliation(s)
- Melody R Lindsay
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana
| | | | - Kristopher M Fecteau
- School of Molecular Sciences, Arizona State University, Tempe, Arizona
- School of Earth and Space Exploration, Arizona State University, Tempe, Arizona
| | - Randal V Debes
- School of Earth and Space Exploration, Arizona State University, Tempe, Arizona
| | | | | | - Huifang Xu
- Department of Geosciences, University of Wisconsin, Madison, Wisconsin
- NASA Astrobiology Institute, Mountain View, California
| | - Tori M Hoehler
- NASA Ames Research Center, Moffett Field, California
- NASA Astrobiology Institute, Mountain View, California
| | - Everett L Shock
- School of Molecular Sciences, Arizona State University, Tempe, Arizona
- School of Earth and Space Exploration, Arizona State University, Tempe, Arizona
- NASA Astrobiology Institute, Mountain View, California
| | - Eric S Boyd
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana
- NASA Astrobiology Institute, Mountain View, California
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11
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Rodrigues-Oliveira T, Belmok A, Vasconcellos D, Schuster B, Kyaw CM. Archaeal S-Layers: Overview and Current State of the Art. Front Microbiol 2017; 8:2597. [PMID: 29312266 PMCID: PMC5744192 DOI: 10.3389/fmicb.2017.02597] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 12/12/2017] [Indexed: 01/01/2023] Open
Abstract
In contrast to bacteria, all archaea possess cell walls lacking peptidoglycan and a number of different cell envelope components have also been described. A paracrystalline protein surface layer, commonly referred to as S-layer, is present in nearly all archaea described to date. S-layers are composed of only one or two proteins and form different lattice structures. In this review, we summarize current understanding of archaeal S-layer proteins, discussing topics such as structure, lattice type distribution among archaeal phyla and glycosylation. The hexagonal lattice type is dominant within the phylum Euryarchaeota, while in the Crenarchaeota this feature is mainly associated with specific orders. S-layers exclusive to the Crenarchaeota have also been described, which are composed of two proteins. Information regarding S-layers in the remaining archaeal phyla is limited, mainly due to organism description through only culture-independent methods. Despite the numerous applied studies using bacterial S-layers, few reports have employed archaea as a study model. As such, archaeal S-layers represent an area for exploration in both basic and applied research.
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Affiliation(s)
- Thiago Rodrigues-Oliveira
- Department of Cell Biology, Institute of Biological Sciences, University of Brasília, Brasília, Brazil
| | - Aline Belmok
- Department of Cell Biology, Institute of Biological Sciences, University of Brasília, Brasília, Brazil
| | - Deborah Vasconcellos
- Department of Cell Biology, Institute of Biological Sciences, University of Brasília, Brasília, Brazil
| | - Bernhard Schuster
- Department of NanoBiotechnology, Institute for Synthetic Bioarchitectures, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Cynthia M. Kyaw
- Department of Cell Biology, Institute of Biological Sciences, University of Brasília, Brasília, Brazil
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12
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Rodionova IA, Vetting MW, Li X, Almo SC, Osterman AL, Rodionov DA. A novel bifunctional transcriptional regulator of riboflavin metabolism in Archaea. Nucleic Acids Res 2017; 45:3785-3799. [PMID: 28073944 PMCID: PMC5397151 DOI: 10.1093/nar/gkw1331] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 12/20/2016] [Indexed: 12/11/2022] Open
Abstract
Riboflavin (vitamin B2) is the precursor of flavin mononucleotide (FMN) and flavin adenine dinucleotide, which are essential coenzymes in all free-living organisms. Riboflavin biosynthesis in many Bacteria but not in Archaea is controlled by FMN-responsive riboswitches. We identified a novel bifunctional riboflavin kinase/regulator (RbkR), which controls riboflavin biosynthesis and transport genes in major lineages of Crenarchaeota, Euryarchaeota and Thaumarchaeota. RbkR proteins are composed of the riboflavin kinase domain and a DNA-binding winged helix-turn-helix-like domain. Using comparative genomics, we predicted RbkR operator sites and reconstructed RbkR regulons in 94 archaeal genomes. While the identified RbkR operators showed significant variability between archaeal lineages, the conserved core of RbkR regulons includes riboflavin biosynthesis genes, known/predicted vitamin uptake transporters and the rbkR gene. The DNA motifs and CTP-dependent riboflavin kinase activity of two RbkR proteins were experimentally validated in vitro. The DNA binding activity of RbkR was stimulated by CTP and suppressed by FMN, a product of riboflavin kinase. The crystallographic structure of RbkR from Thermoplasma acidophilum was determined in complex with CTP and its DNA operator revealing key residues for operator and ligand recognition. Overall, this study contributes to our understanding of metabolic and regulatory networks for vitamin homeostasis in Archaea.
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Affiliation(s)
- Irina A Rodionova
- Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Matthew W Vetting
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Xiaoqing Li
- Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Steven C Almo
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Andrei L Osterman
- Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Dmitry A Rodionov
- Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA 92037, USA.,A.A. Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, 127051 Russia
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13
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Jennings RDM, Moran JJ, Jay ZJ, Beam JP, Whitmore LM, Kozubal MA, Kreuzer HW, Inskeep WP. Integration of Metagenomic and Stable Carbon Isotope Evidence Reveals the Extent and Mechanisms of Carbon Dioxide Fixation in High-Temperature Microbial Communities. Front Microbiol 2017; 8:88. [PMID: 28217111 PMCID: PMC5289995 DOI: 10.3389/fmicb.2017.00088] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 01/12/2017] [Indexed: 11/13/2022] Open
Abstract
Although the biological fixation of CO2 by chemolithoautotrophs provides a diverse suite of organic compounds utilized by chemoorganoheterotrophs as a carbon and energy source, the relative amounts of autotrophic C in chemotrophic microbial communities are not well-established. The extent and mechanisms of CO2 fixation were evaluated across a comprehensive set of high-temperature, chemotrophic microbial communities in Yellowstone National Park by combining metagenomic and stable 13C isotope analyses. Fifteen geothermal sites representing three distinct habitat types (iron-oxide mats, anoxic sulfur sediments, and filamentous “streamer” communities) were investigated. Genes of the 3-hydroxypropionate/4-hydroxybutyrate, dicarboxylate/4-hydroxybutyrate, and reverse tricarboxylic acid CO2 fixation pathways were identified in assembled genome sequence corresponding to the predominant Crenarchaeota and Aquificales observed across this habitat range. Stable 13C analyses of dissolved inorganic and organic C (DIC, DOC), and possible landscape C sources were used to interpret the 13C content of microbial community samples. Isotope mixing models showed that the minimum fractions of autotrophic C in microbial biomass were >50% in the majority of communities analyzed. The significance of CO2 as a C source in these communities provides a foundation for understanding community assembly and succession, and metabolic linkages among early-branching thermophilic autotrophs and heterotrophs.
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Affiliation(s)
- Ryan de Montmollin Jennings
- Department of Land Resources and Environmental Sciences, Montana State UniversityBozeman, MT, USA; Thermal Biology Institute, Montana State UniversityBozeman, MT, USA
| | - James J Moran
- Pacific Northwest National Laboratories Richland, WA, USA
| | - Zackary J Jay
- Department of Land Resources and Environmental Sciences, Montana State UniversityBozeman, MT, USA; Thermal Biology Institute, Montana State UniversityBozeman, MT, USA
| | - Jacob P Beam
- Department of Land Resources and Environmental Sciences, Montana State UniversityBozeman, MT, USA; Thermal Biology Institute, Montana State UniversityBozeman, MT, USA
| | | | - Mark A Kozubal
- Department of Land Resources and Environmental Sciences, Montana State University Bozeman, MT, USA
| | | | - William P Inskeep
- Department of Land Resources and Environmental Sciences, Montana State UniversityBozeman, MT, USA; Thermal Biology Institute, Montana State UniversityBozeman, MT, USA
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14
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Jay ZJ, Beam JP, Kozubal MA, Jennings RD, Rusch DB, Inskeep WP. The distribution, diversity and function of predominant Thermoproteales in high-temperature environments of Yellowstone National Park. Environ Microbiol 2016; 18:4755-4769. [PMID: 27130276 DOI: 10.1111/1462-2920.13366] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 04/25/2016] [Indexed: 12/01/2022]
Abstract
High-temperature environments (> 70°C) contain diverse and abundant members of the crenarchaeal order Thermoproteales. However, a comprehensive study of the distribution and function of diverse members of this group across different habitat types has not been conducted. Consequently, the goals of this study were to determine the distribution of different Thermoproteales genera across geochemically distinct geothermal habitats of Yellowstone National Park, and to identify key functional attributes of major genera that correlate with environmental parameters. Curated sequence assemblies belonging to five genera were characterized in replicate samples of 11 high-temperature communities ranging in pH from 3 to 9. Thermocladium, Vulcanisaeta and Caldivirga spp. were the primary Thermoproteales populations present in low pH (pH < 5) habitats, whereas Thermoproteus populations were found in mildly-acidic (pH 5-6) sulfur sediments, and Pyrobaculum populations were confined to higher pH (pH > 6) sulfur sediments and/or filamentous 'streamer' communities. Metabolic reconstruction and comparative genomics among assemblies show that these populations are primarily chemoorganotrophs that utilize different electron acceptors depending on geochemical conditions. The presence of potential CO2 fixation pathways in some Thermoproteales populations appears to be linked with NiFe hydrogenases, which combined with high levels of H2 in many sulfidic systems, may provide the energy required to fix inorganic C.
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Affiliation(s)
- Zackary J Jay
- Department of Land Resources and Environmental Sciences and Thermal Biology Institute, Montana State University, Bozeman, MT, 59175-3120, USA
| | - Jacob P Beam
- Department of Land Resources and Environmental Sciences and Thermal Biology Institute, Montana State University, Bozeman, MT, 59175-3120, USA
| | - Mark A Kozubal
- Department of Land Resources and Environmental Sciences and Thermal Biology Institute, Montana State University, Bozeman, MT, 59175-3120, USA
| | - Ryan deM Jennings
- Department of Land Resources and Environmental Sciences and Thermal Biology Institute, Montana State University, Bozeman, MT, 59175-3120, USA
| | - Douglas B Rusch
- Center for Genomics and Bioinformatics, Indiana University, Bloomington, IN, USA
| | - William P Inskeep
- Department of Land Resources and Environmental Sciences and Thermal Biology Institute, Montana State University, Bozeman, MT, 59175-3120, USA
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15
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Colman DR, Jay ZJ, Inskeep WP, Jennings RD, Maas KR, Rusch DB, Takacs-Vesbach CD. Novel, Deep-Branching Heterotrophic Bacterial Populations Recovered from Thermal Spring Metagenomes. Front Microbiol 2016; 7:304. [PMID: 27014227 PMCID: PMC4791363 DOI: 10.3389/fmicb.2016.00304] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Accepted: 02/24/2016] [Indexed: 11/24/2022] Open
Abstract
Thermal spring ecosystems are a valuable resource for the discovery of novel hyperthermophilic Bacteria and Archaea, and harbor deeply-branching lineages that provide insight regarding the nature of early microbial life. We characterized bacterial populations in two circumneutral (pH ~8) Yellowstone National Park thermal (T ~80°C) spring filamentous “streamer” communities using random metagenomic DNA sequence to investigate the metabolic potential of these novel populations. Four de novo assemblies representing three abundant, deeply-branching bacterial phylotypes were recovered. Analysis of conserved phylogenetic marker genes indicated that two of the phylotypes represent separate groups of an uncharacterized phylum (for which we propose the candidate phylum name “Pyropristinus”). The third new phylotype falls within the proposed Calescamantes phylum. Metabolic reconstructions of the “Pyropristinus” and Calescamantes populations showed that these organisms appear to be chemoorganoheterotrophs and have the genomic potential for aerobic respiration and oxidative phosphorylation via archaeal-like V-type, and bacterial F-type ATPases, respectively. A survey of similar phylotypes (>97% nt identity) within 16S rRNA gene datasets suggest that the newly described organisms are restricted to terrestrial thermal springs ranging from 70 to 90°C and pH values of ~7–9. The characterization of these lineages is important for understanding the diversity of deeply-branching bacterial phyla, and their functional role in high-temperature circumneutral “streamer” communities.
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Affiliation(s)
- Daniel R Colman
- Department of Biology, University of New Mexico Albuquerque, NM, USA
| | - Zackary J Jay
- Thermal Biology Institute and Department of Land Resources and Environmental Sciences, Montana State University Bozeman, MT, USA
| | - William P Inskeep
- Thermal Biology Institute and Department of Land Resources and Environmental Sciences, Montana State University Bozeman, MT, USA
| | - Ryan deM Jennings
- Thermal Biology Institute and Department of Land Resources and Environmental Sciences, Montana State University Bozeman, MT, USA
| | - Kendra R Maas
- Department of Biology, University of New Mexico Albuquerque, NM, USA
| | - Douglas B Rusch
- Center for Genomics and Bioinformatics, Indiana University Bloomington, IN, USA
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16
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Inskeep WP, Jay ZJ, Macur RE, Clingenpeel S, Tenney A, Lovalvo D, Beam JP, Kozubal MA, Shanks WC, Morgan LA, Kan J, Gorby Y, Yooseph S, Nealson K. Geomicrobiology of sublacustrine thermal vents in Yellowstone Lake: geochemical controls on microbial community structure and function. Front Microbiol 2015; 6:1044. [PMID: 26579074 PMCID: PMC4620420 DOI: 10.3389/fmicb.2015.01044] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 09/14/2015] [Indexed: 12/02/2022] Open
Abstract
Yellowstone Lake (Yellowstone National Park, WY, USA) is a large high-altitude (2200 m), fresh-water lake, which straddles an extensive caldera and is the center of significant geothermal activity. The primary goal of this interdisciplinary study was to evaluate the microbial populations inhabiting thermal vent communities in Yellowstone Lake using 16S rRNA gene and random metagenome sequencing, and to determine how geochemical attributes of vent waters influence the distribution of specific microorganisms and their metabolic potential. Thermal vent waters and associated microbial biomass were sampled during two field seasons (2007–2008) using a remotely operated vehicle (ROV). Sublacustrine thermal vent waters (circa 50–90°C) contained elevated concentrations of numerous constituents associated with geothermal activity including dissolved hydrogen, sulfide, methane and carbon dioxide. Microorganisms associated with sulfur-rich filamentous “streamer” communities of Inflated Plain and West Thumb (pH range 5–6) were dominated by bacteria from the Aquificales, but also contained thermophilic archaea from the Crenarchaeota and Euryarchaeota. Novel groups of methanogens and members of the Korarchaeota were observed in vents from West Thumb and Elliot's Crater (pH 5–6). Conversely, metagenome sequence from Mary Bay vent sediments did not yield large assemblies, and contained diverse thermophilic and nonthermophilic bacterial relatives. Analysis of functional genes associated with the major vent populations indicated a direct linkage to high concentrations of carbon dioxide, reduced sulfur (sulfide and/or elemental S), hydrogen and methane in the deep thermal ecosystems. Our observations show that sublacustrine thermal vents in Yellowstone Lake support novel thermophilic communities, which contain microorganisms with functional attributes not found to date in terrestrial geothermal systems of YNP.
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Affiliation(s)
- William P Inskeep
- Thermal Biology Institute, Montana State University Bozeman, MT, USA ; Land Resources and Environmental Sciences, Montana State University Bozeman, MT, USA
| | - Zackary J Jay
- Land Resources and Environmental Sciences, Montana State University Bozeman, MT, USA
| | - Richard E Macur
- Center for Biofilm Engineering, Montana State University Bozeman, MT, USA
| | | | | | | | - Jacob P Beam
- Land Resources and Environmental Sciences, Montana State University Bozeman, MT, USA
| | - Mark A Kozubal
- Land Resources and Environmental Sciences, Montana State University Bozeman, MT, USA
| | | | | | - Jinjun Kan
- Department of Earth Sciences, University of Southern California Los Angeles, CA, USA
| | - Yuri Gorby
- Department of Earth Sciences, University of Southern California Los Angeles, CA, USA
| | | | - Kenneth Nealson
- Department of Earth Sciences, University of Southern California Los Angeles, CA, USA
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17
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Jay ZJ, Inskeep WP. The distribution, diversity, and importance of 16S rRNA gene introns in the order Thermoproteales. Biol Direct 2015; 10:35. [PMID: 26156036 PMCID: PMC4496867 DOI: 10.1186/s13062-015-0065-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 06/29/2015] [Indexed: 11/30/2022] Open
Abstract
Background Intron sequences are common in 16S rRNA genes of specific thermophilic lineages of Archaea, specifically the Thermoproteales (phylum Crenarchaeota). Environmental sequencing (16S rRNA gene and metagenome) from geothermal habitats in Yellowstone National Park (YNP) has expanded the available datasets for investigating 16S rRNA gene introns. The objectives of this study were to characterize and curate archaeal 16S rRNA gene introns from high-temperature habitats, evaluate the conservation and distribution of archaeal 16S rRNA introns in geothermal systems, and determine which “universal” archaeal 16S rRNA gene primers are impacted by the presence of intron sequences. Results Several new introns were identified and their insertion loci were constrained to thirteen locations across the 16S rRNA gene. Many of these introns encode homing endonucleases, although some introns were short or partial sequences. Pyrobaculum, Thermoproteus, and Caldivirga 16S rRNA genes contained the most abundant and diverse intron sequences. Phylogenetic analysis of introns revealed that sequences within the same locus are distributed biogeographically. The most diverse set of introns were observed in a high-temperature, circumneutral (pH 6) sulfur sediment environment, which also contained the greatest diversity of different Thermoproteales phylotypes. Conclusions The widespread presence of introns in the Thermoproteales indicates a high probability of misalignments using different “universal” 16S rRNA primers employed in environmental microbial community analysis. Reviewers This article was reviewed by Dr. Eugene Koonin and Dr. W. Ford Doolittle. Electronic supplementary material The online version of this article (doi:10.1186/s13062-015-0065-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Zackary J Jay
- Thermal Biology Institute and Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA.
| | - William P Inskeep
- Thermal Biology Institute and Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA.
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