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Buschi E, Dell’Anno A, Tangherlini M, Candela M, Rampelli S, Turroni S, Palladino G, Esposito E, Martire ML, Musco L, Stefanni S, Munari C, Fiori J, Danovaro R, Corinaldesi C. Resistance to freezing conditions of endemic Antarctic polychaetes is enhanced by cryoprotective proteins produced by their microbiome. SCIENCE ADVANCES 2024; 10:eadk9117. [PMID: 38905343 PMCID: PMC11192080 DOI: 10.1126/sciadv.adk9117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 05/14/2024] [Indexed: 06/23/2024]
Abstract
The microbiome plays a key role in the health of all metazoans. Whether and how the microbiome favors the adaptation processes of organisms to extreme conditions, such as those of Antarctica, which are incompatible with most metazoans, is still unknown. We investigated the microbiome of three endemic and widespread species of Antarctic polychaetes: Leitoscoloplos geminus, Aphelochaeta palmeri, and Aglaophamus trissophyllus. We report here that these invertebrates contain a stable bacterial core dominated by Meiothermus and Anoxybacillus, equipped with a versatile genetic makeup and a unique portfolio of proteins useful for coping with extremely cold conditions as revealed by pangenomic and metaproteomic analyses. The close phylosymbiosis between Meiothermus and Anoxybacillus and these Antarctic polychaetes indicates a connection with their hosts that started in the past to support holobiont adaptation to the Antarctic Ocean. The wide suite of bacterial cryoprotective proteins found in Antarctic polychaetes may be useful for the development of nature-based biotechnological applications.
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Affiliation(s)
- Emanuela Buschi
- Department of Ecosustainable Marine Biotechnology, Stazione Zoologica “Anton Dohrn,” Fano Marine Centre, Fano, Italy
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy
| | - Antonio Dell’Anno
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy
| | - Michael Tangherlini
- Department of Research Infrastructures for Marine Biological Resources, Stazione Zoologica “Anton Dohrn,” Fano Marine Centre, Fano, Italy
| | - Marco Candela
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
- Fano Marine Center, the Inter-Institute Center for Research on Marine Biodiversity, Resources and Biotechnologies, Fano, Italy
| | - Simone Rampelli
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
- Fano Marine Center, the Inter-Institute Center for Research on Marine Biodiversity, Resources and Biotechnologies, Fano, Italy
| | - Silvia Turroni
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Giorgia Palladino
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
- Fano Marine Center, the Inter-Institute Center for Research on Marine Biodiversity, Resources and Biotechnologies, Fano, Italy
| | - Erika Esposito
- Department of Chemistry “G. Ciamician” Alma Mater Studiorum, University of Bologna, Bologna, Italy
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italia
| | - Marco Lo Martire
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy
| | - Luigi Musco
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
| | - Sergio Stefanni
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica “Anton Dohrn,” Villa Comunale, Napoli, Italy
| | - Cristina Munari
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Ferrara, Italy
| | - Jessica Fiori
- Department of Chemistry “G. Ciamician” Alma Mater Studiorum, University of Bologna, Bologna, Italy
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italia
| | - Roberto Danovaro
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy
| | - Cinzia Corinaldesi
- Department of Materials, Environmental Sciences and Urban Planning, Polytechnic University of Marche, Ancona, Italy
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Shen L, Liu Y, Chen L, Lei T, Ren P, Ji M, Song W, Lin H, Su W, Wang S, Rooman M, Pucci F. Genomic basis of environmental adaptation in the widespread poly-extremophilic Exiguobacterium group. THE ISME JOURNAL 2024; 18:wrad020. [PMID: 38365240 PMCID: PMC10837837 DOI: 10.1093/ismejo/wrad020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Revised: 12/04/2023] [Accepted: 12/05/2023] [Indexed: 02/18/2024]
Abstract
Delineating cohesive ecological units and determining the genetic basis for their environmental adaptation are among the most important objectives in microbiology. In the last decade, many studies have been devoted to characterizing the genetic diversity in microbial populations to address these issues. However, the impact of extreme environmental conditions, such as temperature and salinity, on microbial ecology and evolution remains unclear so far. In order to better understand the mechanisms of adaptation, we studied the (pan)genome of Exiguobacterium, a poly-extremophile bacterium able to grow in a wide range of environments, from permafrost to hot springs. To have the genome for all known Exiguobacterium type strains, we first sequenced those that were not yet available. Using a reverse-ecology approach, we showed how the integration of phylogenomic information, genomic features, gene and pathway enrichment data, regulatory element analyses, protein amino acid composition, and protein structure analyses of the entire Exiguobacterium pangenome allows to sharply delineate ecological units consisting of mesophilic, psychrophilic, halophilic-mesophilic, and halophilic-thermophilic ecotypes. This in-depth study clarified the genetic basis of the defined ecotypes and identified some key mechanisms driving the environmental adaptation to extreme environments. Our study points the way to organizing the vast microbial diversity into meaningful ecologically units, which, in turn, provides insight into how microbial communities adapt and respond to different environmental conditions in a changing world.
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Affiliation(s)
- Liang Shen
- College of Life Sciences, Anhui Normal University, Wuhu 241000, China
- Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, and Anhui Provincial Engineering Research Centre for Molecular Detection and Diagnostics, Anhui Normal University, Wuhu 241000, China
| | - Yongqin Liu
- Center for the Pan-Third Pole Environment, Lanzhou University, Lanzhou 730000, China
| | - Liangzhong Chen
- College of Life Sciences, Anhui Normal University, Wuhu 241000, China
| | - Tingting Lei
- College of Life Sciences, Anhui Normal University, Wuhu 241000, China
| | - Ping Ren
- College of Life Sciences, Anhui Normal University, Wuhu 241000, China
| | - Mukan Ji
- Center for the Pan-Third Pole Environment, Lanzhou University, Lanzhou 730000, China
| | - Weizhi Song
- Centre for Marine Bio-Innovation, University of New South Wales, Sydney, NSW 2052, Australia
| | - Hao Lin
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Wei Su
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Sheng Wang
- Shanghai Zelixir Biotech Company Ltd., Shanghai 200030, China
| | - Marianne Rooman
- Computational Biology and Bioinformatics, Université Libre de Bruxelles, Brussels 1050, Belgium
- Interuniversity Institute of Bioinformatics in Brussels, Brussels 1050, Belgium
| | - Fabrizio Pucci
- Computational Biology and Bioinformatics, Université Libre de Bruxelles, Brussels 1050, Belgium
- Interuniversity Institute of Bioinformatics in Brussels, Brussels 1050, Belgium
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You Exude What You Eat: How Carbon-, Nitrogen-, and Sulfur-Rich Organic Substrates Shape Microbial Community Composition and the Dissolved Organic Matter Pool. Appl Environ Microbiol 2022; 88:e0155822. [PMID: 36383003 PMCID: PMC9746321 DOI: 10.1128/aem.01558-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Phytoplankton is the major source of labile organic matter in the sunlit ocean, and they are therefore key players in most biogeochemical cycles. However, studies examining the heterotrophic bacterial cycling of specific phytoplankton-derived nitrogen (N)- and sulfur (S)-containing organic compounds are currently lacking at the molecular level. Therefore, the present study investigated how the addition of N-containing (glycine betaine [GBT]) and S-containing (dimethylsulfoniopropionate [DMSP]) organic compounds, as well as glucose, influenced the microbial production of new organic molecules and the microbial community composition. The chemical composition of microbial-produced dissolved organic matter (DOM) was analyzed by ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) demonstrating that CHO-, CHON-, and CHOS-containing molecules were enriched in the glucose, GBT, and DMSP experiments, respectively. High-throughput sequencing showed that Alteromonadales was the dominant group in the glucose, while Rhodobacterales was the most abundant group in both the GBT and DMSP experiments. Cooccurrence network analysis furthermore indicated more complex linkages between the microbial community and organic molecules in the GBT compared with the other two experiments. Our results shed light on how different microbial communities respond to distinct organic compounds and mediate the cycling of ecologically relevant compounds. IMPORTANCE Nitrogen (N)- and sulfur (S)-containing compounds are normally considered part of the labile organic matter pool that fuels heterotrophic bacterial activity in the ocean. Both glycine betaine (GBT) and dimethylsulfoniopropionate (DMSP) are representative N- and S-containing organic compounds, respectively, that are important phytoplankton cellular compounds. The present study therefore examined how the microbial community and the organic matter they produce are influenced by the addition of carbohydrate-containing (glucose), N-containing (GBT), and S-containing (DMSP) organic compounds. The results demonstrate that when these carbon-, N-, and S-rich compounds are added separately, the organic molecules produced by the bacteria growing on them are enriched in the same elements. Similarly, the microbial community composition was also distinct when different compounds were added as the substrate. Overall, this study demonstrates how the microbial communities metabolize and transform different substrates thereby, expanding our understanding of the complexity of links between microbes and substrates in the ocean.
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Cooper ZS, Rapp JZ, Shoemaker AMD, Anderson RE, Zhong ZP, Deming JW. Evolutionary Divergence of Marinobacter Strains in Cryopeg Brines as Revealed by Pangenomics. Front Microbiol 2022; 13:879116. [PMID: 35733954 PMCID: PMC9207381 DOI: 10.3389/fmicb.2022.879116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 05/05/2022] [Indexed: 11/30/2022] Open
Abstract
Marinobacter spp. are cosmopolitan in saline environments, displaying a diverse set of metabolisms that allow them to competitively occupy these environments, some of which can be extreme in both salinity and temperature. Here, we introduce a distinct cluster of Marinobacter genomes, composed of novel isolates and in silico assembled genomes obtained from subzero, hypersaline cryopeg brines, relic seawater-derived liquid habitats within permafrost sampled near Utqiaġvik, Alaska. Using these new genomes and 45 representative publicly available genomes of Marinobacter spp. from other settings, we assembled a pangenome to examine how the new extremophile members fit evolutionarily and ecologically, based on genetic potential and environmental source. This first genus-wide genomic analysis revealed that Marinobacter spp. in general encode metabolic pathways that are thermodynamically favored at low temperature, cover a broad range of organic compounds, and optimize protein usage, e.g., the Entner–Doudoroff pathway, the glyoxylate shunt, and amino acid metabolism. The new isolates contributed to a distinct clade of subzero brine-dwelling Marinobacter spp. that diverged genotypically and phylogenetically from all other Marinobacter members. The subzero brine clade displays genomic characteristics that may explain competitive adaptations to the extreme environments they inhabit, including more abundant membrane transport systems (e.g., for organic substrates, compatible solutes, and ions) and stress-induced transcriptional regulatory mechanisms (e.g., for cold and salt stress) than in the other Marinobacter clades. We also identified more abundant signatures of potential horizontal transfer of genes involved in transcription, the mobilome, and a variety of metabolite exchange systems, which led to considering the importance of this evolutionary mechanism in an extreme environment where adaptation via vertical evolution is physiologically rate limited. Assessing these new extremophile genomes in a pangenomic context has provided a unique view into the ecological and evolutionary history of the genus Marinobacter, particularly with regard to its remarkable diversity and its opportunism in extremely cold and saline environments.
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Affiliation(s)
- Zachary S. Cooper
- School of Oceanography, University of Washington, Seattle, WA, United States
- Astrobiology Program, University of Washington, Seattle, WA, United States
- *Correspondence: Zachary S. Cooper, , orcid.org/0000-0001-6515-7971
| | - Josephine Z. Rapp
- Department of Biochemistry, Microbiology and Bioinformatics, Université Laval, Québec, QC, Canada
- Center for Northern Studies (CEN), Université Laval, Québec, QC, Canada
- Institute of Integrative Biology and Systems (IBIS), Université Laval, Québec, QC, Canada
| | - Anna M. D. Shoemaker
- Department of Earth Sciences, Montana State University, Bozeman, MT, United States
| | - Rika E. Anderson
- Department of Biology, Carleton College, Northfield, MN, United States
| | - Zhi-Ping Zhong
- Byrd Polar and Climate Research Center, Ohio State University, Columbus, OH, United States
- Department of Microbiology, Ohio State University, Columbus, OH, United States
- Center of Microbiome Science, Ohio State University, Columbus, OH, United States
| | - Jody W. Deming
- School of Oceanography, University of Washington, Seattle, WA, United States
- Astrobiology Program, University of Washington, Seattle, WA, United States
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Thalassobacillus, a genus of extreme to moderate environmental halophiles with biotechnological potential. World J Microbiol Biotechnol 2021; 37:147. [PMID: 34363544 DOI: 10.1007/s11274-021-03116-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/29/2021] [Indexed: 01/09/2023]
Abstract
Thalassobacillus is a moderately halophilic genus that has been isolated from several sites worldwide, such as hypersaline lakes, saline soils, salt flats, and volcanic mud. Halophilic bacteria have provided functional stable biomolecules in harsh conditions for industrial purposes. Despite its potential biotechnological applications, Thalassobacillus has not been fully characterized yet. This review describes the Thalassobacillus genus, with the few species reported, pointing out its possible applications in enzymes (amylases, cellulases, xylanases, and others), biosurfactants, bioactive compounds, biofuels production, bioremediation, and plant growth promotion. The Thalassobacillus genus represents a little-explored biological resource but with a high potential.
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Rapp JZ, Sullivan MB, Deming JW. Divergent Genomic Adaptations in the Microbiomes of Arctic Subzero Sea-Ice and Cryopeg Brines. Front Microbiol 2021; 12:701186. [PMID: 34367102 PMCID: PMC8339730 DOI: 10.3389/fmicb.2021.701186] [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: 04/27/2021] [Accepted: 06/29/2021] [Indexed: 11/16/2022] Open
Abstract
Subzero hypersaline brines are liquid microbial habitats within otherwise frozen environments, where concentrated dissolved salts prevent freezing. Such extreme conditions presumably require unique microbial adaptations, and possibly altered ecologies, but specific strategies remain largely unknown. Here we examined prokaryotic taxonomic and functional diversity in two seawater-derived subzero hypersaline brines: first-year sea ice, subject to seasonally fluctuating conditions; and ancient cryopeg, under relatively stable conditions geophysically isolated in permafrost. Overall, both taxonomic composition and functional potential were starkly different. Taxonomically, sea-ice brine communities (∼105 cells mL–1) had greater richness, more diversity and were dominated by bacterial genera, including Polaribacter, Paraglaciecola, Colwellia, and Glaciecola, whereas the more densely inhabited cryopeg brines (∼108 cells mL–1) lacked these genera and instead were dominated by Marinobacter. Functionally, however, sea ice encoded fewer accessory traits and lower average genomic copy numbers for shared traits, though DNA replication and repair were elevated; in contrast, microbes in cryopeg brines had greater genetic versatility with elevated abundances of accessory traits involved in sensing, responding to environmental cues, transport, mobile elements (transposases and plasmids), toxin-antitoxin systems, and type VI secretion systems. Together these genomic features suggest adaptations and capabilities of sea-ice communities manifesting at the community level through seasonal ecological succession, whereas the denser cryopeg communities appear adapted to intense bacterial competition, leaving fewer genera to dominate with brine-specific adaptations and social interactions that sacrifice some members for the benefit of others. Such cryopeg genomic traits provide insight into how long-term environmental stability may enable life to survive extreme conditions.
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Affiliation(s)
- Josephine Z Rapp
- School of Oceanography, University of Washington, Seattle, WA, United States
| | - Matthew B Sullivan
- Byrd Polar and Climate Research Center, Ohio State University, Columbus, OH, United States.,Department of Microbiology, Ohio State University, Columbus, OH, United States.,Department of Civil, Environmental and Geodetic Engineering, Ohio State University, Columbus, OH, United States.,Center of Microbiome Science, Ohio State University, Columbus, OH, United States
| | - Jody W Deming
- School of Oceanography, University of Washington, Seattle, WA, United States
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Mudge MC, Nunn BL, Firth E, Ewert M, Hales K, Fondrie WE, Noble WS, Toner J, Light B, Junge KA. Subzero, saline incubations of
Colwellia psychrerythraea
reveal strategies and biomarkers for sustained life in extreme icy environments. Environ Microbiol 2021; 23:3840-3866. [DOI: 10.1111/1462-2920.15485] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 03/22/2021] [Indexed: 11/26/2022]
Affiliation(s)
- Miranda C. Mudge
- Department of Genome Sciences University of Washington Seattle WA USA
- Department of Molecular and Cellular Biology University of Washington Seattle WA USA
| | - Brook L. Nunn
- Department of Genome Sciences University of Washington Seattle WA USA
- Astrobiology Program University of Washington Seattle WA USA
| | - Erin Firth
- Applied Physics Lab, Polar Science Center University of Washington Seattle WA USA
| | - Marcela Ewert
- Applied Physics Lab, Polar Science Center University of Washington Seattle WA USA
| | - Kianna Hales
- Department of Genome Sciences University of Washington Seattle WA USA
| | | | - William S. Noble
- Department of Genome Sciences University of Washington Seattle WA USA
- Paul G. Allen School of Computer Science and Engineering University of Washington Seattle WA USA
| | - Jonathan Toner
- Department of Earth and Space Sciences University of Washington Seattle WA USA
| | - Bonnie Light
- Applied Physics Lab, Polar Science Center University of Washington Seattle WA USA
| | - Karen A. Junge
- Applied Physics Lab, Polar Science Center University of Washington Seattle WA USA
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Peoples LM, Kyaw TS, Ugalde JA, Mullane KK, Chastain RA, Yayanos AA, Kusube M, Methé BA, Bartlett DH. Distinctive gene and protein characteristics of extremely piezophilic Colwellia. BMC Genomics 2020; 21:692. [PMID: 33023469 PMCID: PMC7542103 DOI: 10.1186/s12864-020-07102-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 09/24/2020] [Indexed: 01/05/2023] Open
Abstract
Background The deep ocean is characterized by low temperatures, high hydrostatic pressures, and low concentrations of organic matter. While these conditions likely select for distinct genomic characteristics within prokaryotes, the attributes facilitating adaptation to the deep ocean are relatively unexplored. In this study, we compared the genomes of seven strains within the genus Colwellia, including some of the most piezophilic microbes known, to identify genomic features that enable life in the deep sea. Results Significant differences were found to exist between piezophilic and non-piezophilic strains of Colwellia. Piezophilic Colwellia have a more basic and hydrophobic proteome. The piezophilic abyssal and hadal isolates have more genes involved in replication/recombination/repair, cell wall/membrane biogenesis, and cell motility. The characteristics of respiration, pilus generation, and membrane fluidity adjustment vary between the strains, with operons for a nuo dehydrogenase and a tad pilus only present in the piezophiles. In contrast, the piezosensitive members are unique in having the capacity for dissimilatory nitrite and TMAO reduction. A number of genes exist only within deep-sea adapted species, such as those encoding d-alanine-d-alanine ligase for peptidoglycan formation, alanine dehydrogenase for NADH/NAD+ homeostasis, and a SAM methyltransferase for tRNA modification. Many of these piezophile-specific genes are in variable regions of the genome near genomic islands, transposases, and toxin-antitoxin systems. Conclusions We identified a number of adaptations that may facilitate deep-sea radiation in members of the genus Colwellia, as well as in other piezophilic bacteria. An enrichment in more basic and hydrophobic amino acids could help piezophiles stabilize and limit water intrusion into proteins as a result of high pressure. Variations in genes associated with the membrane, including those involved in unsaturated fatty acid production and respiration, indicate that membrane-based adaptations are critical for coping with high pressure. The presence of many piezophile-specific genes near genomic islands highlights that adaptation to the deep ocean may be facilitated by horizontal gene transfer through transposases or other mobile elements. Some of these genes are amenable to further study in genetically tractable piezophilic and piezotolerant deep-sea microorganisms.
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Affiliation(s)
- Logan M Peoples
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92093-0202, USA.,Flathead Lake Biological Station, University of Montana, Polson, MT, 59860, USA
| | - Than S Kyaw
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92093-0202, USA
| | - Juan A Ugalde
- Millennium Initiative for Collaborative Research on Bacterial Resistance (MICROB-R), Santiago, Chile
| | - Kelli K Mullane
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92093-0202, USA
| | - Roger A Chastain
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92093-0202, USA
| | - A Aristides Yayanos
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92093-0202, USA
| | - Masataka Kusube
- Department of Material Science, National Institute of Technology, Wakayama College, 77 Noshima, Nada-cho, Gobo, Wakayama, 644-0023, Japan
| | - Barbara A Methé
- Center for Microbiome and Medicine, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Douglas H Bartlett
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92093-0202, USA.
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Kumar V, Thakur V, Ambika, Kumar V, Kumar R, Singh D. Genomic insights revealed physiological diversity and industrial potential for Glaciimonas sp. PCH181 isolated from Satrundi glacier in Pangi-Chamba Himalaya. Genomics 2020; 112:637-646. [DOI: 10.1016/j.ygeno.2019.04.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 04/18/2019] [Accepted: 04/21/2019] [Indexed: 12/17/2022]
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Comparative genomics analysis of Nitriliruptoria reveals the genomic differences and salt adaptation strategies. Extremophiles 2019; 24:249-264. [PMID: 31820112 DOI: 10.1007/s00792-019-01150-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 11/25/2019] [Indexed: 12/22/2022]
Abstract
The group Nitriliruptoria, recently classified as a separate class of phylum Actinobacteria, has five members at present, which belong to halophilic or halotolerant Actinobacteria. Here, we sequenced the genomes of Egicoccus halophilus EGI 80432T and Egibacter rhizosphaerae EGI 80759T, and performed a comparative genomics approach to analyze the genomic differences and salt adaptation mechanisms in Nitriliruptoria. Phylogenetic analysis suggested that Euzebya tangerina F10T has a closer phylogenetic relationship to Euzebya rosea DSW09T, while genomic analysis revealed highest genomic similarity with Nitriliruptor alkaliphilus ANL-iso2T and E. halophilus EGI 80432T. Genomic differences of Nitriliruptoria were mainly observed in genome size, gene contents, and the amounts of gene in per functional categories. Furthermore, our analysis also revealed that Nitriliruptoria possess similar synthesis systems of solutes, such as trehalose, glutamine, glutamate, and proline. On the other hand, each member of Nitriliruptoria species possesses specific mechanisms, K+ influx and efflux, betaine and ectoine synthesis, and compatible solutes transport to survive in various high-salt environments.
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Torstensson A, Young JN, Carlson LT, Ingalls AE, Deming JW. Use of exogenous glycine betaine and its precursor choline as osmoprotectants in Antarctic sea-ice diatoms 1. JOURNAL OF PHYCOLOGY 2019; 55:663-675. [PMID: 30685888 DOI: 10.1111/jpy.12839] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Accepted: 01/14/2019] [Indexed: 06/09/2023]
Abstract
Wide salinity ranges experienced during the seasonal freeze and melt of sea ice likely constrain many biological processes. Microorganisms generally protect against fluctuating salinities through the uptake, production, and release of compatible solutes. Little is known, however, about the use or fate of glycine betaine (GBT hereafter), one of the most common compatible solutes, in sea-ice diatoms confronted with shifts in salinity. We quantified intracellular concentrations and used [14 C]-labeled compounds to track the uptake and fate of the nitrogen-containing osmolyte GBT and its precursor choline in three Antarctic sea-ice diatoms Nitzschia lecointei, Navicula cf. perminuta, and Fragilariopsis cylindrus at -1°C. Experiments show that these diatoms have effective transporters for GBT, but take up lesser amounts of choline. Neither compound was respired. Uptake of GBT protected cells against hyperosmotic shock and corresponded with reduced production of extracellular polysaccharides in N. lecointei cells, which released 85% of the retained GBT following hypoosmotic shock. The ability of sea-ice diatoms to rapidly scavenge and release compatible solutes is likely an important strategy for survival during steep fluctuations in salinity. The release and recycling of compatible solutes may play an important role in algal-bacterial interactions and nitrogen cycling within the semi-enclosed brines of sea ice.
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Affiliation(s)
- Anders Torstensson
- School of Oceanography, University of Washington, Box 357940, Seattle, Washington, 98195-7940, USA
| | - Jodi N Young
- School of Oceanography, University of Washington, Box 357940, Seattle, Washington, 98195-7940, USA
| | - Laura T Carlson
- School of Oceanography, University of Washington, Box 357940, Seattle, Washington, 98195-7940, USA
| | - Anitra E Ingalls
- School of Oceanography, University of Washington, Box 357940, Seattle, Washington, 98195-7940, USA
| | - Jody W Deming
- School of Oceanography, University of Washington, Box 357940, Seattle, Washington, 98195-7940, USA
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12
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Maccario L, Carpenter SD, Deming JW, Vogel TM, Larose C. Sources and selection of snow-specific microbial communities in a Greenlandic sea ice snow cover. Sci Rep 2019; 9:2290. [PMID: 30783153 PMCID: PMC6381142 DOI: 10.1038/s41598-019-38744-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 12/14/2018] [Indexed: 11/09/2022] Open
Abstract
Sea ice and its snow cover are critical for global processes including climate regulation and biogeochemical cycles. Despite an increase in studies focused on snow microorganisms, the ecology of snow inhabitants remains unclear. In this study, we investigated sources and selection of a snowpack-specific microbial community by comparing metagenomes from samples collected in a Greenlandic fjord within a vertical profile including atmosphere, snowpack with four distinct layers of snow, sea ice brine and seawater. Microbial communities in all snow layers derived from mixed sources, both marine and terrestrial, and were more similar to atmospheric communities than to sea ice or seawater communities. The surface snow metagenomes were characterized by the occurrence of genes involved in photochemical stress resistance, primary production and metabolism of diverse carbon sources. The basal saline snow layer that was in direct contact with the sea ice surface harbored a higher abundance of cells than the overlying snow layers, with a predominance of Alteromonadales and a higher relative abundance of marine representatives. However, the overall taxonomic structure of the saline layer was more similar to that of other snow layers and the atmosphere than to underlying sea ice and seawater. The expulsion of relatively nutrient-rich sea ice brine into basal snow might have stimulated the growth of copiotrophic psychro- and halotolerant snow members. Our study indicates that the size, composition and function of snowpack microbial communities over sea ice were influenced primarily by atmospheric deposition and inflow of sea ice brine and that they form a snow-specific assemblage reflecting the particular environmental conditions of the snowpack habitat.
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Affiliation(s)
- Lorrie Maccario
- Environmental Microbial Genomics, Laboratoire Ampère, CNRS, École Centrale de Lyon, Écully, France.
- Microbiology Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
| | | | - Jody W Deming
- School of Oceanography, University of Washington, Seattle, USA
| | - Timothy M Vogel
- Environmental Microbial Genomics, Laboratoire Ampère, CNRS, École Centrale de Lyon, Écully, France
| | - Catherine Larose
- Environmental Microbial Genomics, Laboratoire Ampère, CNRS, École Centrale de Lyon, Écully, France
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13
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McFarlin KM, Perkins MJ, Field JA, Leigh MB. Biodegradation of Crude Oil and Corexit 9500 in Arctic Seawater. Front Microbiol 2018; 9:1788. [PMID: 30147678 PMCID: PMC6096335 DOI: 10.3389/fmicb.2018.01788] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 07/17/2018] [Indexed: 12/22/2022] Open
Abstract
The need to understand the biodegradation of oil and chemical dispersants in Arctic marine environments is increasing alongside growth in oil exploration and transport in the region. We chemically quantified biodegradation and abiotic losses of crude oil and Corexit 9500, when present separately, in incubations of Arctic seawater and identified microorganisms potentially involved in biodegradation of these substrates based on shifts in bacterial community structure (16S rRNA genes) and abundance of biodegradation genes (GeoChip 5.0 microarray). Incubations were performed over 28-day time courses using surface seawater collected from near-shore and offshore locations in the Chukchi Sea. Within 28 days, the indigenous microbial community biodegraded 36% (k = 0.010 day-1) and 41% (k = 0.014 day-1) of oil and biodegraded 77% and 33% (k = 0.015 day-1) of the Corexit 9500 component dioctyl sodium sulfosuccinate (DOSS) in respective near-shore and offshore incubations. Non-ionic surfactants (Span 80, Tween 80, and Tween 85) present in Corexit 9500 were non-detectable by 28 days due to a combination of abiotic losses and biodegradation. Microorganisms utilized oil and Corexit 9500 as growth substrates during the incubation, with the Corexit 9500 stimulating more extensive growth than oil within 28 days. Taxa known to include oil-degrading bacteria (e.g., Oleispira, Polaribacter, and Colwellia) and some oil biodegradation genes (e.g., alkB, nagG, and pchCF) increased in relative abundance in response to both oil and Corexit 9500. These results increase our understanding of oil and dispersant biodegradation in the Arctic and suggest that some bacteria may be capable of biodegrading both oil and Corexit 9500.
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Affiliation(s)
- Kelly M McFarlin
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, United States
| | - Matt J Perkins
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR, United States
| | - Jennifer A Field
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR, United States
| | - Mary B Leigh
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, United States
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14
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Mukhtar S, Mehnaz S, Mirza MS, Mirza BS, Malik KA. Diversity of Bacillus-like bacterial community in the rhizospheric and non-rhizospheric soil of halophytes (Salsola stocksii and Atriplex amnicola), and characterization of osmoregulatory genes in halophilic Bacilli. Can J Microbiol 2018; 64:567-579. [DOI: 10.1139/cjm-2017-0544] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Salinity is one of the major abiotic stresses; a total of 3% of the world’s land mass is affected by salinity. Approximately 6.3 million hectares of land in Pakistan is affected by salinity to varying degrees, and most of the areas are arid to semiarid with low annual precipitation. The aim of the present study is to identify and characterize Bacillus and Bacillus-derived bacterial genera from the rhizospheric and non-rhizospheric soil samples from the Khewra Salt Mine, Pakistan, by using culture-independent and -dependent methods. Seven Bacillus-like bacterial genera, Bacillus, Halobacillus, Virgibacillus, Brevibacillus, Paenibacillus, Tumebacillus, and Lysinibacillus, were detected by using pyrosequencing analysis, whereas only four genera, Bacillus, Halobacillus, Oceanobacillus, and Virgibacillus, were identified by culture-dependent methods. Most of the Bacillus-like isolates identified in this study were moderately halophilic, alkaliphilic, and mesophilic bacteria and were considered a good source of hydrolytic enzymes because of their ability to degrade proteins, carbohydrates, and lipids. Eight Bacillus-like strains from the genera Bacillus, Halobacillus, Oceanobacillus, and Virgibacillus showed positive results for the presence of ectABC gene cluster (ectoine), six strains could synthesize betaine from choline, and six strains tested positive for the synthesis of proline from either glutamate or ornithine by using proline dehydrogenase enzyme.
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Affiliation(s)
- Salma Mukhtar
- Department of Biological Sciences, Forman Christian College (A Chartered University), Ferozepur Road, Lahore 54600, Pakistan
- Molecular, Cell & Developmental Biology, UCLA, 621 Charles Young Drive South, Los Angeles, CA 90095-1606, USA
| | - Samina Mehnaz
- Department of Biological Sciences, Forman Christian College (A Chartered University), Ferozepur Road, Lahore 54600, Pakistan
| | - Muhammad Sajjad Mirza
- Environmental Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Jhang Road, Faisalabad, Pakistan
| | - Babur Saeed Mirza
- Missouri State University, 901 S. National Avenue, Springfield, MO 65897, USA
| | - Kauser Abdulla Malik
- Department of Biological Sciences, Forman Christian College (A Chartered University), Ferozepur Road, Lahore 54600, Pakistan
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15
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Abstract
It is well known that cold environments are predominant over the Earth and there are a great number of reports analyzing bacterial adaptations to cold. Most of these works are focused on characteristics traditionally involved in cold adaptation, such as the structural adjustment of enzymes, maintenance of membrane fluidity, expression of cold shock proteins and presence of compatible solutes. Recent works based mainly on novel "omic" technologies have presented evidence of the presence of other important features to thrive in cold. In this work, we analyze cold-adapted bacteria, looking for strategies involving novel features, and/or activation of non-classical metabolisms for a cold lifestyle. Metabolic traits related to energy generation, compounds and mechanisms involved in stress resistance and cold adaptation, as well as characteristics of the cell envelope, are analyzed in heterotrophic cold-adapted bacteria. In addition, metagenomic, metatranscriptomic and metaproteomic data are used to detect key functions in bacterial communities inhabiting cold environments.
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Affiliation(s)
- Paula M Tribelli
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1428EGA Buenos Aires, Argentina.
- IQUIBICEN, CONICET, C1428EGA Buenos Aires, Argentina.
| | - Nancy I López
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1428EGA Buenos Aires, Argentina.
- IQUIBICEN, CONICET, C1428EGA Buenos Aires, Argentina.
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16
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Mackelprang R, Burkert A, Haw M, Mahendrarajah T, Conaway CH, Douglas TA, Waldrop MP. Microbial survival strategies in ancient permafrost: insights from metagenomics. ISME JOURNAL 2017; 11:2305-2318. [PMID: 28696425 PMCID: PMC5607373 DOI: 10.1038/ismej.2017.93] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 02/25/2017] [Accepted: 04/27/2017] [Indexed: 01/14/2023]
Abstract
In permafrost (perennially frozen ground) microbes survive oligotrophic conditions, sub-zero temperatures, low water availability and high salinity over millennia. Viable life exists in permafrost tens of thousands of years old but we know little about the metabolic and physiological adaptations to the challenges presented by life in frozen ground over geologic time. In this study we asked whether increasing age and the associated stressors drive adaptive changes in community composition and function. We conducted deep metagenomic and 16 S rRNA gene sequencing across a Pleistocene permafrost chronosequence from 19 000 to 33 000 years before present (kyr). We found that age markedly affected community composition and reduced diversity. Reconstruction of paleovegetation from metagenomic sequence suggests vegetation differences in the paleo record are not responsible for shifts in community composition and function. Rather, we observed shifts consistent with long-term survival strategies in extreme cryogenic environments. These include increased reliance on scavenging detrital biomass, horizontal gene transfer, chemotaxis, dormancy, environmental sensing and stress response. Our results identify traits that may enable survival in ancient cryoenvironments with no influx of energy or new materials.
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Affiliation(s)
- Rachel Mackelprang
- Department of Biology, California State University Northridge, Northridge, CA, USA
| | - Alexander Burkert
- Department of Biology, California State University Northridge, Northridge, CA, USA
| | - Monica Haw
- US Geological Survey, Menlo Park, CA, USA
| | - Tara Mahendrarajah
- Department of Biology, California State University Northridge, Northridge, CA, USA
| | | | - Thomas A Douglas
- US Army Cold Regions Research and Engineering Laboratory, Fort Wainwright, AK, USA
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17
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Ntougias S, Polkowska Ż, Nikolaki S, Dionyssopoulou E, Stathopoulou P, Doudoumis V, Ruman M, Kozak K, Namieśnik J, Tsiamis G. Bacterial Community Structures in Freshwater Polar Environments of Svalbard. Microbes Environ 2016; 31:401-409. [PMID: 27725345 PMCID: PMC5158112 DOI: 10.1264/jsme2.me16074] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Two thirds of Svalbard archipelago islands in the High Arctic are permanently covered with glacial ice and snow. Polar bacterial communities in the southern part of Svalbard were characterized using an amplicon sequencing approach. A total of 52,928 pyrosequencing reads were analyzed in order to reveal bacterial community structures in stream and lake surface water samples from the Fuglebekken and Revvatnet basins of southern Svalbard. Depending on the samples examined, bacterial communities at a higher taxonomic level mainly consisted either of Bacteroidetes, Betaproteobacteria, and Microgenomates (OP11) or Planctomycetes, Betaproteobacteria, and Bacteroidetes members, whereas a population of Microgenomates was prominent in 2 samples. At the lower taxonomic level, bacterial communities mostly comprised Microgenomates, Comamonadaceae, Flavobacteriaceae, Legionellales, SM2F11, Parcubacteria (OD1), and TM7 members at different proportions in each sample. The abundance of OTUs shared in common among samples was greater than 70%, with the exception of samples in which the proliferation of Planctomycetaceae, Phycisphaeraceae, and Candidatus Methylacidiphilum spp. lowered their relative abundance. A multi-variable analysis indicated that As, Pb, and Sb were the main environmental factors influencing bacterial profiles. We concluded that the bacterial communities in the polar aquatic ecosystems examined mainly consisted of freshwater and marine microorganisms involved in detritus mineralization, with a high proportion of zooplankton-associated taxa also being identified.
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Affiliation(s)
- Spyridon Ntougias
- Department of Environmental Engineering, Democritus University of Thrace
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18
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Choline Catabolism in Burkholderia thailandensis Is Regulated by Multiple Glutamine Amidotransferase 1-Containing AraC Family Transcriptional Regulators. J Bacteriol 2016; 198:2503-14. [PMID: 27381916 PMCID: PMC4999938 DOI: 10.1128/jb.00372-16] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 06/30/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Burkholderia thailandensis is a soil-dwelling bacterium that shares many metabolic pathways with the ecologically similar, but evolutionarily distant, Pseudomonas aeruginosa Among the diverse nutrients it can utilize is choline, metabolizable to the osmoprotectant glycine betaine and subsequently catabolized as a source of carbon and nitrogen, similar to P. aeruginosa Orthologs of genes in the choline catabolic pathway in these two bacteria showed distinct differences in gene arrangement as well as an additional orthologous transcriptional regulator in B. thailandensis In this study, we showed that multiple glutamine amidotransferase 1 (GATase 1)-containing AraC family transcription regulators (GATRs) are involved in regulation of the B. thailandensis choline catabolic pathway (gbdR1, gbdR2, and souR). Using genetic analyses and sequencing the transcriptome in the presence and absence of choline, we identified the likely regulons of gbdR1 (BTH_II1869) and gbdR2 (BTH_II0968). We also identified a functional ortholog for P. aeruginosa souR, a GATR that regulates the metabolism of sarcosine to glycine. GbdR1 is absolutely required for expression of the choline catabolic locus, similar to P. aeruginosa GbdR, while GbdR2 is important to increase expression of the catabolic locus. Additionally, the B. thailandensis SouR ortholog (BTH_II0994) is required for catabolism of choline and its metabolites as carbon sources, whereas in P. aeruginosa, SouR function can by bypassed by GbdR. The strategy employed by B. thailandensis represents a distinct regulatory solution to control choline catabolism and thus provides both an evolutionary counterpoint and an experimental system to analyze the acquisition and regulation of this pathway during environmental growth and infection. IMPORTANCE Many proteobacteria that occupy similar environmental niches have horizontally acquired orthologous genes for metabolism of compounds useful in their shared environment. The arrangement and differential regulation of these components can help us understand both the evolution of these systems and the potential roles these pathways have in the biology of each bacterium. Here, we describe the transcriptome response of Burkholderia thailandensis to the eukaryote-enriched molecule choline, identify the regulatory pathway governing choline catabolism, and compare the pathway to that previously described for Pseudomonas aeruginosa These data support a multitiered regulatory network in B. thailandensis, with conserved orthologs in the select agents Burkholderia pseudomallei and Burkholderia mallei, as well as the opportunistic lung pathogens in the Burkholderia cepacia clade.
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19
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Broaders E, O'Brien C, Gahan CGM, Marchesi JR. Evidence for plasmid-mediated salt tolerance in the human gut microbiome and potential mechanisms. FEMS Microbiol Ecol 2016; 92:fiw019. [PMID: 26850157 PMCID: PMC5831011 DOI: 10.1093/femsec/fiw019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 01/31/2016] [Indexed: 11/25/2022] Open
Abstract
The human gut microbiome is critical to health and wellbeing. It hosts a complex ecosystem comprising a multitude of bacterial species, which contributes functionality that would otherwise be absent from the host. Transient and commensal bacteria in the gut must withstand many stresses. The influence of mobile genetic elements such as plasmids in stress adaptation within the ecosystem is poorly understood. Using a mobilomic approach we found evidence for plasmid-mediated osmotolerance as a phenotype amongst the Proteobacteria in healthy faecal slurries. A transconjugant carrying multiple plasmids acquired from healthy faecal slurry demonstrated increased osmotolerance in the presence of metal salts, particularly potassium chloride, which was not evident in the recipient. Pyrosequencing and analysis of the total plasmid DNA demonstrated the presence of plasmid-borne osmotolerance systems (including KdpD and H-NS) which may be linked to the observed phenotype. This is the first report of a transferable osmotolerance phenotype in gut commensals and may have implications for the transfer of osmotolerance in other niches. There is evidence of a transferable osmotolerance phenotype in gut commensals which may have implications for the transfer of osmotolerance in other niches.
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Affiliation(s)
- Eileen Broaders
- Alimentary Pharmabiotic Centre, University College Cork, College Road, Cork, T12 YT20, Ireland Department of Microbiology, University College Cork, College Road, Cork, T12 YT20, Ireland
| | - Ciarán O'Brien
- Department of Microbiology, University College Cork, College Road, Cork, T12 YT20, Ireland
| | - Cormac G M Gahan
- Alimentary Pharmabiotic Centre, University College Cork, College Road, Cork, T12 YT20, Ireland Department of Microbiology, University College Cork, College Road, Cork, T12 YT20, Ireland School of Pharmacy, University College Cork, Cork, T12 YT20, Ireland
| | - Julian R Marchesi
- Alimentary Pharmabiotic Centre, University College Cork, College Road, Cork, T12 YT20, Ireland School of Biosciences, Cardiff University, Cardiff CF103AX, UK Centre for Digestive and Gut Health, Imperial College London, London W2 1NY, UK
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20
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Boetius A, Anesio AM, Deming JW, Mikucki JA, Rapp JZ. Microbial ecology of the cryosphere: sea ice and glacial habitats. Nat Rev Microbiol 2015; 13:677-90. [PMID: 26344407 DOI: 10.1038/nrmicro3522] [Citation(s) in RCA: 206] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The Earth's cryosphere comprises those regions that are cold enough for water to turn into ice. Recent findings show that the icy realms of polar oceans, glaciers and ice sheets are inhabited by microorganisms of all three domains of life, and that temperatures below 0 °C are an integral force in the diversification of microbial life. Cold-adapted microorganisms maintain key ecological functions in icy habitats: where sunlight penetrates the ice, photoautotrophy is the basis for complex food webs, whereas in dark subglacial habitats, chemoautotrophy reigns. This Review summarizes current knowledge of the microbial ecology of frozen waters, including the diversity of niches, the composition of microbial communities at these sites and their biogeochemical activities.
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Affiliation(s)
- Antje Boetius
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany.,Max Planck Institute for Marine Microbiology, Celsiusstraße 1, 28359 Bremen, Germany
| | - Alexandre M Anesio
- Bristol Glaciology Center, School of Geographical Sciences, University of Bristol, BS8 1SS, UK
| | - Jody W Deming
- School of Oceanography, Box 357940, University of Washington, Seattle, Washington 98195, USA
| | - Jill A Mikucki
- Department of Biology, 276 Bicentennial Way, Middlebury College, Middlebury, Vermont 05753, USA
| | - Josephine Z Rapp
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany.,Max Planck Institute for Marine Microbiology, Celsiusstraße 1, 28359 Bremen, Germany
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21
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Nunn BL, Slattery KV, Cameron KA, Timmins-Schiffman E, Junge K. Proteomics of Colwellia psychrerythraea at subzero temperatures - a life with limited movement, flexible membranes and vital DNA repair. Environ Microbiol 2015; 17:2319-35. [PMID: 25471130 DOI: 10.1111/1462-2920.12691] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 10/23/2014] [Accepted: 10/23/2014] [Indexed: 11/27/2022]
Abstract
The mechanisms that allow psychrophilic bacteria to remain metabolically active at subzero temperatures result from form and function of their proteins. We present first proteomic evidence of physiological changes of the marine psychrophile Colwellia psychrerythraea 34H (Cp34H) after exposure to subzero temperatures (-1, and -10°C in ice) through 8 weeks. Protein abundance was compared between different treatments to understand the effects of temperature and time, independently and jointly, within cells transitioning to, and being maintained in ice. Parallel [3H]-leucine and [3H]-thymidine incubations indicated active protein and DNA synthesis to -10°C. Mass spectrometry-based proteomics identified 1763 proteins across four experimental treatments. Proteins involved in osmolyte regulation and polymer secretion were found constitutively present across all treatments, suggesting that they are required for metabolic success below 0°C. Differentially abundant protein groups indicated a reallocation of resources from DNA binding to DNA repair and from motility to chemo-taxis and sensing. Changes to iron and nitrogen metabolism, cellular membrane structures, and protein synthesis and folding were also revealed. By elucidating vital strategies during life in ice, this study provides novel insight into the extensive molecular adaptations that occur in cold-adapted marine organisms to sustain cellular function in their habitat.
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Affiliation(s)
- Brook L Nunn
- Department of Genome Sciences, University of Washington, Box 355065, Seattle, WA, 98195, USA
| | - Krystal V Slattery
- Applied Physics Laboratory, Polar Science Center, University of Washington, Box 355640, Seattle, WA, 98195, USA
| | - Karen A Cameron
- Applied Physics Laboratory, Polar Science Center, University of Washington, Box 355640, Seattle, WA, 98195, USA
| | - Emma Timmins-Schiffman
- Department of Genome Sciences, University of Washington, Box 355065, Seattle, WA, 98195, USA
| | - Karen Junge
- Applied Physics Laboratory, Polar Science Center, University of Washington, Box 355640, Seattle, WA, 98195, USA
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22
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Perfumo A, Elsaesser A, Littmann S, Foster RA, Kuypers MMM, Cockell CS, Kminek G. Epifluorescence, SEM, TEM and nanoSIMS image analysis of the cold phenotype of Clostridium psychrophilum at subzero temperatures. FEMS Microbiol Ecol 2014; 90:869-82. [PMID: 25319134 DOI: 10.1111/1574-6941.12443] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 10/12/2014] [Accepted: 10/12/2014] [Indexed: 11/27/2022] Open
Abstract
We have applied an image-based approach combining epifluorescence microscopy, electron microscopy and nanoscale secondary ion mass spectrometry (nanoSIMS) with stable isotope probing to examine directly the characteristic cellular features involved in the expression of the cold phenotype in the Antarctic bacterium Clostridium psychrophilum exposed to a temperature range from +5 to -15 °C under anoxic conditions. We observed dramatic morphological changes depending on temperature. At temperatures below -10 °C, cell division was inhibited and consequently filamentous growth predominated. Bacterial cells appeared surrounded by a remarkably thick cell wall and a capsule formed of long exopolysaccharide fibres. Moreover, bacteria were entirely embedded within a dense extracellular matrix, suggesting a role both in cryo-protection and in the cycling of nutrients and genetic material. Strings of extracellular DNA, transient cell membrane permeability and release of membrane vesicles were observed that suggest that evolution via transfer of genetic material may be especially active under frozen conditions. While at -5 °C, the bacterial population was metabolically healthy, at temperatures below -10 °C, most cells showed no sign of active metabolism or the metabolic flux was extremely slowed down; instead of being consumed, carbon was accumulated and stored in intracellular granules as in preparation for a long-term survival.
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Affiliation(s)
- Amedea Perfumo
- European Space Agency, TEC-QI, Noordwijk, The Netherlands
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23
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Feng S, Powell SM, Wilson R, Bowman JP. Extensive gene acquisition in the extremely psychrophilic bacterial species Psychroflexus torquis and the link to sea-ice ecosystem specialism. Genome Biol Evol 2014; 6:133-48. [PMID: 24391155 PMCID: PMC3914696 DOI: 10.1093/gbe/evt209] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Sea ice is a highly dynamic and productive environment that includes a diverse array of psychrophilic prokaryotic and eukaryotic taxa distinct from the underlying water column. Because sea ice has only been extensive on Earth since the mid-Eocene, it has been hypothesized that bacteria highly adapted to inhabit sea ice have traits that have been acquired through horizontal gene transfer (HGT). Here we compared the genomes of the psychrophilic bacterium Psychroflexus torquis ATCC 700755T, associated with both Antarctic and Arctic sea ice, and its closely related nonpsychrophilic sister species, P. gondwanensis ACAM 44T. Results show that HGT has occurred much more extensively in P. torquis in comparison to P. gondwanensis. Genetic features that can be linked to the psychrophilic and sea ice-specific lifestyle of P. torquis include genes for exopolysaccharide (EPS) and polyunsaturated fatty acid (PUFA) biosynthesis, numerous specific modes of nutrient acquisition, and proteins putatively associated with ice-binding, light-sensing (bacteriophytochromes), and programmed cell death (metacaspases). Proteomic analysis showed that several genes associated with these traits are highly translated, especially those involved with EPS and PUFA production. Because most of the genes relating to the ability of P. torquis to dwell in sea-ice ecosystems occur on genomic islands that are absent in closely related P. gondwanensis, its adaptation to the sea-ice environment appears driven mainly by HGT. The genomic islands are rich in pseudogenes, insertional elements, and addiction modules, suggesting that gene acquisition is being followed by a process of genome reduction potentially indicative of evolving ecosystem specialism.
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Affiliation(s)
- Shi Feng
- Food Safety Centre, Tasmanian Institute of Agriculture, University of Tasmania, Australia
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24
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Ewert M, Deming JW. Bacterial responses to fluctuations and extremes in temperature and brine salinity at the surface of Arctic winter sea ice. FEMS Microbiol Ecol 2014; 89:476-89. [DOI: 10.1111/1574-6941.12363] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 05/30/2014] [Accepted: 06/02/2014] [Indexed: 11/29/2022] Open
Affiliation(s)
- Marcela Ewert
- School of Oceanography; University of Washington; Seattle WA USA
| | - Jody W. Deming
- School of Oceanography; University of Washington; Seattle WA USA
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