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Ren Z, Ma K, Jia X, Wang Q, Zhang C, Li X. Metagenomics Unveils Microbial Diversity and Their Biogeochemical Roles in Water and Sediment of Thermokarst Lakes in the Yellow River Source Area. MICROBIAL ECOLOGY 2023; 85:904-915. [PMID: 35650293 DOI: 10.1007/s00248-022-02053-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 05/25/2022] [Indexed: 05/04/2023]
Abstract
Thermokarst lakes have long been recognized as biogeochemical hotspots, especially as sources of greenhouse gases. On the Qinghai-Tibet Plateau, thermokarst lakes are experiencing extensive changes due to faster warming. For a deep understanding of internal lake biogeochemical processes, we applied metagenomic analyses to investigate the microbial diversity and their biogeochemical roles in sediment and water of thermokarst lakes in the Yellow River Source Area (YRSA). Sediment microbial communities (SMCs) had lower species and gene richness than water microbial communities (WMCs). Bacteria were the most abundant component in both SMCs and WMCs with significantly different abundant genera. The functional analyses showed that both SMCs and WMCs had low potential in methanogenesis but strong in aerobic respiration, nitrogen assimilation, exopolyphosphatase, glycerophosphodiester phosphodiesterases, and polyphosphate kinase. Moreover, SMCs were enriched in genes involved in anaerobic carbon fixation, aerobic carbon fixation, fermentation, most nitrogen metabolism pathways, dissimilatory sulfate reduction, sulfide oxidation, polysulfide reduction, 2-phosphonopropionate transporter, and phosphate regulation. WMCs were enriched in genes involved in assimilatory sulfate reduction, sulfur mineralization, phosphonoacetate hydrolase, and phosphonate transport. Functional potentials suggest the differences of greenhouse gas emission, nutrient cycling, and living strategies between SMCs and WMCs. This study provides insight into the main biogeochemical processes and their properties in thermokarst lakes in YRSA, improving our understanding of the roles and fates of these lakes in a warming world.
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Affiliation(s)
- Ze Ren
- Research and Development Center for Watershed Environmental Eco-Engineering, Advanced Institute of Natural Sciences, Beijing Normal University, 18 Jinfeng Road, Xiangzhou Distract, Zhuhai, 519087, Guangdong, China.
- School of Environment, Beijing Normal University, Beijing, 100875, China.
| | - Kang Ma
- School of Environment, Beijing Normal University, Beijing, 100875, China
| | - Xuan Jia
- College of Education for the Future, Beijing Normal University, Zhuhai, 519087, China
| | - Qing Wang
- Research and Development Center for Watershed Environmental Eco-Engineering, Advanced Institute of Natural Sciences, Beijing Normal University, 18 Jinfeng Road, Xiangzhou Distract, Zhuhai, 519087, Guangdong, China
- School of Environment, Beijing Normal University, Beijing, 100875, China
| | - Cheng Zhang
- Research and Development Center for Watershed Environmental Eco-Engineering, Advanced Institute of Natural Sciences, Beijing Normal University, 18 Jinfeng Road, Xiangzhou Distract, Zhuhai, 519087, Guangdong, China
- School of Engineering Technology, Beijing Normal University, Zhuhai, 519087, China
| | - Xia Li
- Research and Development Center for Watershed Environmental Eco-Engineering, Advanced Institute of Natural Sciences, Beijing Normal University, 18 Jinfeng Road, Xiangzhou Distract, Zhuhai, 519087, Guangdong, China
- School of Environment, Beijing Normal University, Beijing, 100875, China
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2
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Santini TC, Gramenz L, Southam G, Zammit C. Microbial Community Structure Is Most Strongly Associated With Geographical Distance and pH in Salt Lake Sediments. Front Microbiol 2022; 13:920056. [PMID: 35756015 PMCID: PMC9221066 DOI: 10.3389/fmicb.2022.920056] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 05/09/2022] [Indexed: 11/16/2022] Open
Abstract
Salt lakes are globally significant microbial habitats, hosting substantial novel microbial diversity and functional capacity. Extremes of salinity and pH both pose major challenges for survival of microbial life in terrestrial and aquatic environments, and are frequently cited as primary influences on microbial diversity across a wide variety of environments. However, few studies have attempted to identify spatial and geochemical contributions to microbial community composition, functional capacity, and environmental tolerances in salt lakes, limiting exploration of novel halophilic and halotolerant microbial species and their potential biotechnological applications. Here, we collected sediment samples from 16 salt lakes at pH values that ranged from pH 4 to 9, distributed across 48,000 km2 of the Archaean Yilgarn Craton in southwestern Australia to identify associations between environmental factors and microbial community composition, and used a high throughput culturing approach to identify the limits of salt and pH tolerance during iron and sulfur oxidation in these microbial communities. Geographical distance between lakes was the primary contributor to variation in microbial community composition, with pH identified as the most important geochemical contributor to variation in microbial community composition. Microbial community composition split into two clear groups by pH: Bacillota dominated microbial communities in acidic saline lakes, whereas Euryarchaeota dominated microbial communities in alkaline saline lakes. Iron oxidation was observed at salinities up to 160 g L-1 NaCl at pH values as low as pH 1.5, and sulfur oxidation was observed at salinities up to 160 g L-1 NaCl between pH values 2-10, more than doubling previously observed tolerances to NaCl salinity amongst cultivable iron and sulfur oxidizers at these extreme pH values. OTU level diversity in the salt lake microbial communities emerged as the major indicator of iron- and sulfur-oxidizing capacity and environmental tolerances to extremes of pH and salinity. Overall, when bioprospecting for novel microbial functional capacity and environmental tolerances, our study supports sampling from remote, previously unexplored, and maximally distant locations, and prioritizing for OTU level diversity rather than present geochemical conditions.
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Affiliation(s)
- Talitha C. Santini
- UWA School of Agriculture and Environment, The University of Western Australia, Crawley, WA, Australia
| | - Lucy Gramenz
- School of Earth and Environmental Sciences, The University of Queensland, St Lucia, QLD, Australia
| | - Gordon Southam
- School of Earth and Environmental Sciences, The University of Queensland, St Lucia, QLD, Australia
| | - Carla Zammit
- School of Earth and Environmental Sciences, The University of Queensland, St Lucia, QLD, Australia
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3
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Active Microbial Airborne Dispersal and Biomorphs as Confounding Factors for Life Detection in the Cell-Degrading Brines of the Polyextreme Dallol Geothermal Field. mBio 2022; 13:e0030722. [PMID: 35384698 PMCID: PMC9040726 DOI: 10.1128/mbio.00307-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Determining the precise limits of life in polyextreme environments is challenging. Studies along gradients of polyextreme conditions in the Dallol proto-volcano area (Danakil salt desert, Ethiopia) showed the occurrence of archaea-dominated communities (up to 99%) in several hypersaline systems but strongly suggested that life did not thrive in the hyperacidic (pH ∼0), hypersaline (∼35% [wt/vol],) and sometimes hot (up to 108°C) ponds of the Dallol dome. However, it was recently claimed that archaea flourish in these brines based on the detection of one Nanohaloarchaeotas 16S rRNA gene and fluorescent in situ hybridization (FISH) experiments with archaea-specific probes. Here, we characterized the diversity of microorganisms in aerosols over Dallol, and we show that, in addition to typical bacteria from soil/dust, they transport halophilic archaea likely originating from neighboring hypersaline ecosystems. We also show that cells and DNA from cultures and natural local halophilic communities are rapidly destroyed upon contact with Dallol brine. Furthermore, we confirm the widespread occurrence of mineral particles, including silica-based biomorphs, in Dallol brines. FISH experiments using appropriate controls show that DNA fluorescent probes and dyes unspecifically bind to mineral precipitates in Dallol brines; cellular morphologies were unambiguously observed only in nearby hypersaline ecosystems. Our results show that airborne cell dispersal and unspecific binding of fluorescent probes are confounding factors likely affecting previous inferences of archaea thriving in Dallol. They highlight the need for controls and the consideration of alternative abiotic explanations before safely drawing conclusions about the presence of life in polyextreme terrestrial or extraterrestrial systems.
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4
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Abstract
Water is the cellular milieu, drives all biochemistry within Earth's biosphere and facilitates microbe-mediated decay processes. Instead of reviewing these topics, the current article focuses on the activities of water as a preservative-its capacity to maintain the long-term integrity and viability of microbial cells-and identifies the mechanisms by which this occurs. Water provides for, and maintains, cellular structures; buffers against thermodynamic extremes, at various scales; can mitigate events that are traumatic to the cell membrane, such as desiccation-rehydration, freeze-thawing and thermal shock; prevents microbial dehydration that can otherwise exacerbate oxidative damage; mitigates against biocidal factors (in some circumstances reducing ultraviolet radiation and diluting solute stressors or toxic substances); and is effective at electrostatic screening so prevents damage to the cell by the intense electrostatic fields of some ions. In addition, the water retained in desiccated cells (historically referred to as 'bound' water) plays key roles in biomacromolecular structures and their interactions even for fully hydrated cells. Assuming that the components of the cell membrane are chemically stable or at least repairable, and the environment is fairly constant, water molecules can apparently maintain membrane geometries over very long periods provided these configurations represent thermodynamically stable states. The spores and vegetative cells of many microbes survive longer in the presence of vapour-phase water (at moderate-to-high relative humidities) than under more-arid conditions. There are several mechanisms by which large bodies of water, when cooled during subzero weather conditions remain in a liquid state thus preventing potentially dangerous (freeze-thaw) transitions for their microbiome. Microbial life can be preserved in pure water, freshwater systems, seawater, brines, ice/permafrost, sugar-rich aqueous milieux and vapour-phase water according to laboratory-based studies carried out over periods of years to decades and some natural environments that have yielded cells that are apparently thousands, or even (for hypersaline fluid inclusions of mineralized NaCl) hundreds of millions, of years old. The term preservative has often been restricted to those substances used to extend the shelf life of foods (e.g. sodium benzoate, nitrites and sulphites) or those used to conserve dead organisms, such as ethanol or formaldehyde. For living microorganisms however, the ultimate preservative may actually be water. Implications of this role are discussed with reference to the ecology of halophiles, human pathogens and other microbes; food science; biotechnology; biosignatures for life and other aspects of astrobiology; and the large-scale release/reactivation of preserved microbes caused by global climate change.
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Affiliation(s)
- John E. Hallsworth
- Institute for Global Food SecuritySchool of Biological SciencesQueen’s University Belfast19 Chlorine GardensBelfastBT9 5DLUK
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5
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Belilla J, Iniesto M, Moreira D, Benzerara K, López-García JM, López-Archilla AI, Reboul G, Deschamps P, Gérard E, López-García P. Archaeal overdominance close to life-limiting conditions in geothermally influenced hypersaline lakes at the Danakil Depression, Ethiopia. Environ Microbiol 2021; 23:7168-7182. [PMID: 34519149 DOI: 10.1111/1462-2920.15771] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 09/05/2021] [Accepted: 09/08/2021] [Indexed: 01/04/2023]
Abstract
The Dallol protovolcanic area on the Danakil Depression (Afar region, Ethiopia) exhibits unique hydrothermal manifestations in hypersaline context, yielding varied polyextreme physicochemical conditions. Previous studies identified a wide archaeal diversity in less extreme brines but failed to identify microorganisms thriving in either high-chaotropicity, low-water-activity brines or hyperacidic-hypersaline Na-Fe-rich brines. Recently, we accessed several small lakes under intense degassing activity adjacent to the Round Mountain, west to the Dallol dome [Western Canyon Lakes (WCL); WCL1-5]. They exhibited intermediate parameter combinations (pH ~ 5, 34%-41% (weight/volume) NaCl-dominated salts with relatively high levels of chaotropic Mg-Ca salts) that should allow to better constrain life limits. These lakes were overwhelmingly dominated by Archaea, encompassing up to 99% of prokaryotic 16S rRNA gene amplicon sequences in metabarcoding studies. The majority belonged to Halobacteriota and Nanohaloarchaeota, the latter representing up to half of prokaryotic sequences. Optical and epifluorescence microscopy showed active cells in natural samples and diverse morphotypes in enrichment cultures. Scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy revealed tiny cells (200-300 nm diameter) epibiotically associated with somewhat larger cells (0.6-1 μm) but also the presence of silica-dominated precipitates of similar size and shape, highlighting the difficulty of distinguishing microbes from mineral biomorphs in this kind of low-biomass systems.
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Affiliation(s)
- Jodie Belilla
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France
| | - Miguel Iniesto
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France
| | - David Moreira
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France
| | - Karim Benzerara
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, CNRS, Sorbonne Université, Muséum National d'Histoire Naturelle, Paris, France
| | | | | | - Guillaume Reboul
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France
| | - Philippe Deschamps
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France
| | | | - Purificación López-García
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France
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6
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Ghori NUH, Wise MJ, Whiteley AS. Temporal Microbial Community Dynamics Within a Unique Acid Saline Lake. Front Microbiol 2021; 12:649594. [PMID: 34248867 PMCID: PMC8264302 DOI: 10.3389/fmicb.2021.649594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 06/04/2021] [Indexed: 11/13/2022] Open
Abstract
Lake Magic is an extremely acidic, hypersaline lake found in Western Australia, with the highest concentrations of aluminum and silica in the world. Previous studies of Lake Magic diversity have revealed that the lake hosts acid- and halotolerant bacterial and fungal species. However, they have not canvassed microbial population dynamics across flooding, evapo-concentration and desiccation stages. In this study, we used amplicon sequencing and potential function prediction on sediment and salt mat samples. We observed that the bacterial and fungal diversity in Lake Magic is strongly driven by carbon, temperature, pH and salt concentrations at the different stages of the lake. We also saw that the fungal diversity decreased as the environmental conditions became more extreme. However, prokaryotic diversity was very dynamic and bacteria dominated archaeal species, both in abundance and diversity, perhaps because bacteria better tolerate the extreme variation in conditions. Bacterial species diversity was the highest during early flooding stage and decreased during more stressful conditions. We observed an increase in acid tolerant and halotolerant species in the sediment, involved in functions such as sulfur and iron metabolism, i.e., species involved in buffering the external environment. Thus, due to activity within the microbial community, the environmental conditions in the sediment do not change to the same degree as conditions in the salt mat, resulting in the sediment becoming a safe haven for microbes, which are able to thrive during the extreme conditions of the evapo-concentration and desiccation stages.
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Affiliation(s)
- Noor-Ul-Huda Ghori
- School of Agriculture and Environment, The University of Western Australia, Perth, WA, Australia.,The Marshall Centre of Infectious Diseases, School of Biological Sciences, The University of Western Australia, Perth, WA, Australia
| | - Michael J Wise
- The Marshall Centre of Infectious Diseases, School of Biological Sciences, The University of Western Australia, Perth, WA, Australia.,Department of Computer Science and Engineering, The University of Western Australia, Perth, WA, Australia
| | - Andrew S Whiteley
- School of Agriculture and Environment, The University of Western Australia, Perth, WA, Australia.,Centre for Environment and Life Sciences, CSIRO Land Water, Perth, WA, Australia
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7
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Benison KC, O'Neill WK, Blain D, Hallsworth JE. Water Activities of Acid Brine Lakes Approach the Limit for Life. ASTROBIOLOGY 2021; 21:729-740. [PMID: 33819431 PMCID: PMC8219186 DOI: 10.1089/ast.2020.2334] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 02/09/2021] [Indexed: 05/19/2023]
Abstract
Water activity is an important characteristic for describing unusual waters and is a determinant of habitability for microorganisms. However, few empirical studies of water activity have been done for natural waters exhibiting an extreme chemistry. Here, we investigate water activity for acid brines from Western Australia and Chile with pH as low as 1.4, salinities as high as 32% total dissolved solids, and complex chemical compositions. These acid brines host diverse communities of extremophilic microorganisms, including archaea, bacteria, algae, and fungi, according to metagenomic analyses. For the most extreme brine, its water activity (0.714) was considerably lower than that of saturated (pure) NaCl brine. This study provides a thermodynamic insight into life within end-member natural waters that lie at, or possibly beyond, the very edge of habitable space on Earth.
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Affiliation(s)
- Kathleen C. Benison
- Department of Geology and Geography, West Virginia University, Morgantown, West Virginia, USA
| | - William K. O'Neill
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, Northern Ireland
| | - David Blain
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, Northern Ireland
| | - John E. Hallsworth
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, Northern Ireland
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8
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Hallsworth JE, Mancinelli RL, Conley CA, Dallas TD, Rinaldi T, Davila AF, Benison KC, Rapoport A, Cavalazzi B, Selbmann L, Changela H, Westall F, Yakimov MM, Amils R, Madigan MT. Astrobiology of life on Earth. Environ Microbiol 2021; 23:3335-3344. [PMID: 33817931 DOI: 10.1111/1462-2920.15499] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 04/02/2021] [Indexed: 11/29/2022]
Abstract
Astrobiology is mistakenly regarded by some as a field confined to studies of life beyond Earth. Here, we consider life on Earth through an astrobiological lens. Whereas classical studies of microbiology historically focused on various anthropocentric sub-fields (such as fermented foods or commensals and pathogens of crop plants, livestock and humans), addressing key biological questions via astrobiological approaches can further our understanding of all life on Earth. We highlight potential implications of this approach through the articles in this Environmental Microbiology special issue 'Ecophysiology of Extremophiles'. They report on the microbiology of places/processes including low-temperature environments and chemically diverse saline- and hypersaline habitats; aspects of sulphur metabolism in hypersaline lakes, dysoxic marine waters, and thermal acidic springs; biology of extremophile viruses; the survival of terrestrial extremophiles on the surface of Mars; biological soils crusts and rock-associated microbes of deserts; subsurface and deep biosphere, including a salticle formed within Triassic halite; and interactions of microbes with igneous and sedimentary rocks. These studies, some of which we highlight here, contribute to our understanding of the spatiotemporal reach of Earth'sfunctional biosphere, and the tenacity of terrestrial life. Their findings will help set the stage for future work focused on the constraints for life, and how organisms adapt and evolve to circumvent these constraints.
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Affiliation(s)
- John E Hallsworth
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 7BL, UK
| | - Rocco L Mancinelli
- Bay Area Environmental Research Institute, NASA Ames Research Center, Mountain View, CA, 94035, USA
| | | | - Tiffany D Dallas
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 7BL, UK
| | - Teresa Rinaldi
- Department of Biology and Biotechnology, Sapienza University of Rome, Rome, 00185, Italy
| | | | - Kathleen C Benison
- Department of Geology and Geography, West Virginia University, Morgantown, WV, 26506-6300, USA
| | - Alexander Rapoport
- Laboratory of Cell Biology, Institute of Microbiology and Biotechnology, University of Latvia, Jelgavas Str., 1-537, Riga, LV-1004, Latvia
| | - Barbara Cavalazzi
- Department of Biological, Geological and Environmental Sciences, University of Bologna, Bologna, 40126, Italy
| | - Laura Selbmann
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, 01100, Italy.,Italian Antarctic National Museum (MNA), Mycological Section, Genoa, 16128, Italy
| | - Hitesh Changela
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China.,Department of Earth and Planetary Science, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Frances Westall
- CNRS, Ctr Biophys Mol UPR 4301, Rue Charles Sadron, CS 80054, Orleans, F-45071, France
| | - Michail M Yakimov
- Institute of Marine Biological Resources and Biotechnology, IRBIM-CNR, Messina, 98122, Italy
| | - Ricardo Amils
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid (CBMSO, CSICUAM), Cantoblanco, Madrid, 28049, Spain.,Centro de Astrobiología (CAB, INTA-CSIC), Torrejón de Ardoz, 28055, Spain
| | - Michael T Madigan
- School of Biological Sciences, Department of Microbiology, Southern Illinois University, Carbondale, IL, 62901, USA
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9
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Daebeler A, Kitzinger K, Koch H, Herbold CW, Steinfeder M, Schwarz J, Zechmeister T, Karst SM, Albertsen M, Nielsen PH, Wagner M, Daims H. Exploring the upper pH limits of nitrite oxidation: diversity, ecophysiology, and adaptive traits of haloalkalitolerant Nitrospira. THE ISME JOURNAL 2020; 14:2967-2979. [PMID: 32709974 PMCID: PMC7784846 DOI: 10.1038/s41396-020-0724-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 06/01/2020] [Accepted: 07/16/2020] [Indexed: 12/27/2022]
Abstract
Nitrite-oxidizing bacteria of the genus Nitrospira are key players of the biogeochemical nitrogen cycle. However, little is known about their occurrence and survival strategies in extreme pH environments. Here, we report on the discovery of physiologically versatile, haloalkalitolerant Nitrospira that drive nitrite oxidation at exceptionally high pH. Nitrospira distribution, diversity, and ecophysiology were studied in hypo- and subsaline (1.3-12.8 g salt/l), highly alkaline (pH 8.9-10.3) lakes by amplicon sequencing, metagenomics, and cultivation-based approaches. Surprisingly, not only were Nitrospira populations detected, but they were also considerably diverse with presence of members from Nitrospira lineages I, II and IV. Furthermore, the ability of Nitrospira enrichment cultures to oxidize nitrite at neutral to highly alkaline pH of 10.5 was demonstrated. Metagenomic analysis of a newly enriched Nitrospira lineage IV species, "Candidatus Nitrospira alkalitolerans", revealed numerous adaptive features of this organism to its extreme environment. Among them were a sodium-dependent N-type ATPase and NADH:quinone oxidoreductase next to the proton-driven forms usually found in Nitrospira. Other functions aid in pH and cation homeostasis and osmotic stress defense. "Ca. Nitrospira alkalitolerans" also possesses group 2a and 3b [NiFe] hydrogenases, suggesting it can use hydrogen as alternative energy source. These results reveal how Nitrospira cope with strongly fluctuating pH and salinity conditions and expand our knowledge of nitrogen cycling in extreme habitats.
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Affiliation(s)
- Anne Daebeler
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Vienna, Austria.
| | - Katharina Kitzinger
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Vienna, Austria
- Max Planck Institute for Marine Microbiology, Department of Biogeochemistry, Bremen, Germany
| | - Hanna Koch
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Vienna, Austria
- Department of Microbiology, Radboud University, Nijmegen, The Netherlands
| | - Craig W Herbold
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Vienna, Austria
| | - Michaela Steinfeder
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Vienna, Austria
| | - Jasmin Schwarz
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Vienna, Austria
| | | | - Søren M Karst
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Mads Albertsen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Per H Nielsen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Michael Wagner
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Vienna, Austria
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
- University of Vienna, The Comammox Research Platform, Vienna, Austria
| | - Holger Daims
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, Vienna, Austria.
- University of Vienna, The Comammox Research Platform, Vienna, Austria.
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10
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Bishop JL, Gross C, Danielsen J, Parente M, Murchie SL, Horgan B, Wray JJ, Viviano C, Seelos FP. Multiple mineral horizons in layered outcrops at Mawrth Vallis, Mars, signify changing geochemical environments on early Mars. ICARUS 2020; 341:113634. [PMID: 34045770 PMCID: PMC8152300 DOI: 10.1016/j.icarus.2020.113634] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Refined calibrations of CRISM images are enabling identification of smaller deposits of unique aqueous materials on Mars that reveal changing environmental conditions at the region surrounding Mawrth Vallis. Through characterization of these clay-sulfate assemblages and their association with the layered, phyllosilicate units of this region, more details of the aqueous geochemical history can be gleaned. A stratigraphy including five distinct mineral horizons is mapped using compositional data from CRISM over CTX and HRSC imagery across 100s of km and from CRISM over HiRISE imagery across 100s of meters. Transitions in mineralogic units were characterized using visible/near-infrared (VNIR) spectral properties and surface morphology. We identified and characterized complex "doublet" type spectral signatures with two bands between 2.2 and 2.3 μm at one stratigraphic horizon. Based on comparisons with terrestrial sites, the spectral "doublet" unit described here may reflect the remnants of a salty, evaporative period that existed on Mars during the transition from formation of Fe-rich phyllosilicates to Al-rich phyllosilicates. Layered outcrops observed at Mawrth Vallis are thicker than in other altered regions of Mars, but may represent processes that were more widespread in wet regions of the planet during its early history. The aqueous geochemical environments supporting the outcrops observed here include: (i) the formation of Fe3+-rich smectites in a warm and wet environment, (ii) overlain by a thin ferrous-bearing clay unit that could be associated with heating or reducing conditions, (iii) followed by a transition to salty and/or acidic alteration phases and sulfates (characterized by the spectral "doublet" shape) in an evaporative setting, (iv) formation of Al-rich phyllosilicates through pedogenesis or acid leaching, and (v) finally persistence of poorly crystalline aluminosilicates marking the end of the warm climate on early Mars. The "doublet" type units described here are likely composed of clay-sulfate assemblages formed in saline, acidic evaporative environments similar to those found in Western Australia and the Atacama desert. Despite the chemically extreme and variable waters present at these terrestrial, saline lake environments, active ecosystems are present; thus, these "doublet" type units may mark exciting areas for continued exploration important to astrobiology on Mars.
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Affiliation(s)
- Janice L. Bishop
- SETI Institute, Mountain View, CA, United States of America
- Freie Universität Berlin, Berlin, Germany
| | | | - Jacob Danielsen
- SETI Institute, Mountain View, CA, United States of America
- San Jose State University, San Jose, CA, United States of America
| | - Mario Parente
- University of Massachusetts at Amherst, Amherst, MA, United States of America
| | - Scott L. Murchie
- Johns Hopkins University Applied Physics Lab, Laurel, MD, United States of America
| | - Briony Horgan
- Purdue University, West Lafayette, IN, United States of America
| | - James J. Wray
- Georgia Institute of Technology, Atlanta, GA, United States of America
| | - Christina Viviano
- Johns Hopkins University Applied Physics Lab, Laurel, MD, United States of America
| | - Frank P. Seelos
- Johns Hopkins University Applied Physics Lab, Laurel, MD, United States of America
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11
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Johnson SS, Millan M, Graham H, Benison KC, Williams AJ, McAdam A, Knudson CA, Andrejkovičová S, Achilles C. Lipid Biomarkers in Ephemeral Acid Salt Lake Mudflat/Sandflat Sediments: Implications for Mars. ASTROBIOLOGY 2020; 20:167-178. [PMID: 32022603 DOI: 10.1089/ast.2017.1812] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Sedimentary strata on Mars often contain a mix of sulfates, iron oxides, chlorides, and phyllosilicates, a mineral assemblage that is unique on Earth to acid brine environments. To help characterize the astrobiological potential of depositional environments with similar minerals present, samples from four naturally occurring acidic salt lakes and adjacent mudflats/sandflats in the vicinity of Norseman, Western Australia, were collected and analyzed. Lipid biomarkers were extracted and quantified, revealing biomarkers from vascular plants alongside trace microbial lipids. The resilience of lipids from dead organic material in these acid saline sediments through the pervasive stages of early diagenesis lends support to the idea that sulfates, in tandem with phyllosilicates and iron oxides, could be a viable target for biomarkers on Mars. To fully understand the astrobiological potential of these depositional environments, additional investigations of organic preservation in ancient acidic saline sedimentary environments are needed.
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Affiliation(s)
- Sarah Stewart Johnson
- Department of Biology, Georgetown University, Washington, District of Columbia
- Program on Science, Technology, and International Affairs, Georgetown University, Washington, District of Columbia
| | - Maëva Millan
- Department of Biology, Georgetown University, Washington, District of Columbia
- NASA Goddard Space Flight Center, Greenbelt, Maryland
| | | | - Kathleen C Benison
- Department of Geology and Geography, West Virginia University, Morgantown, West Virginia
| | - Amy J Williams
- Department of Geological Sciences, University of Florida, Gainesville, Florida
| | - Amy McAdam
- NASA Goddard Space Flight Center, Greenbelt, Maryland
| | - Christine A Knudson
- NASA Goddard Space Flight Center, Greenbelt, Maryland
- Center for Research and Exploration in Space Sciences and Technology/University of Maryland College Park, College Park, Maryland
| | - Slavka Andrejkovičová
- NASA Goddard Space Flight Center, Greenbelt, Maryland
- Center for Research and Exploration in Space Sciences and Technology/University of Maryland College Park, College Park, Maryland
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12
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Liu JL, Yao J, Duran R, Mihucz VG, Hudson-Edwards KA. Bacterial shifts during in-situ mineralization bio-treatment to non-ferrous metal(loid) tailings. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 255:113165. [PMID: 31546074 DOI: 10.1016/j.envpol.2019.113165] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 09/01/2019] [Accepted: 09/02/2019] [Indexed: 06/10/2023]
Abstract
Nonferrous mine tailings have caused serious problems of co-contamination with metal(loid)s. It is still a global challenge to cost-effectively manage and mitigate the effect of the mining wastes. We conducted an in-situ bio-treatment of non-ferrous metal(loid) tailings using a microbial consortium of sulfate reducing bacteria (SRB). During the bio-treatment, the transformation of metal(loid)s (such as Cu, Fe, Mn, Pb, Sb, and Zn) into oxidizable and residual fractions in the subsurface tended to be higher than that observed in the surface. As well the mineral compositions changed becoming more complex, indicating that the sulfur reducing process of bio-treatment shaped the bio-transformation of metal(loid)s. The added SRB genera, especially Desulfotomaculum genus, colonized the tailings suggesting the coalescence of SRB consortia with indigenous communities of tailings. Such observation provides new insights for understanding the functional microbial community coalescence applied to bio-treatment. PICRUSt analysis revealed presence of genes involved in sulfate reduction, both assimilatory and dissimilatory. The potential for the utilization of both inorganic and organic sulfur compounds as S source, as well as the presence of sulfite oxidation genes indicated that SRB play an important role in the transformation of metal(loid)s. We advocate that the management of microorganisms involved in S-cycle is of paramount importance for the in situ bio-treatment of tailings, which provide new insights for the implementation of bio-treatments for mitigating the effect of tailings.
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Affiliation(s)
- Jian-Li Liu
- School of Water Resource and Environment Engineering, China University of Geosciences (Beijing), 100083, China
| | - Jun Yao
- School of Water Resource and Environment Engineering, China University of Geosciences (Beijing), 100083, China.
| | - Robert Duran
- School of Water Resource and Environment Engineering, China University of Geosciences (Beijing), 100083, China; Equipe Environnement et Microbiologie, MELODY group, Université de Pau et des Pays de l'Adour/E2S UPPA, IPREM UMR CNRS 5254, BP 1155, 64013, Pau Cedex, France
| | - Victor G Mihucz
- Sino-Hungarian Joint Research Laboratory for Environmental Sciences and Health, ELTE-Eötvös Loránd University, H-1117, Budapest, Pázmány Péter stny. 1/A, Hungary
| | - Karen A Hudson-Edwards
- Environment & Sustainability Institute and Camborne School of Mines, University of Exeter, Penryn, Cornwall, TR10 9DF, UK
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13
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Belilla J, Moreira D, Jardillier L, Reboul G, Benzerara K, López-García JM, Bertolino P, López-Archilla AI, López-García P. Hyperdiverse archaea near life limits at the polyextreme geothermal Dallol area. Nat Ecol Evol 2019; 3:1552-1561. [PMID: 31666740 PMCID: PMC6837875 DOI: 10.1038/s41559-019-1005-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 09/16/2019] [Indexed: 11/13/2022]
Abstract
Microbial life has adapted to various individual extreme conditions; yet, organisms simultaneously adapted to very low pH, high salt and high temperature are unknown. We combined environmental 16S/18S rRNA-gene metabarcoding, cultural approaches, fluorescence-activated cell sorting, scanning electron microscopy and chemical analyses to study samples along such unique polyextreme gradients in the Dallol-Danakil area (Ethiopia). We identify two physicochemical barriers to life in the presence of surface liquid water defined by: i) high chaotropicity-low water activity in Mg2+/Ca2+-dominated brines and ii) hyperacidity-salt combinations (pH~0/NaCl-dominated salt-saturation). When detected, life was dominated by highly diverse ultrasmall archaea widely distributed across phyla with and without previously known halophilic members. We hypothesize that high cytoplasmic K+-level was an original archaeal adaptation to hyperthermophily, subsequently exapted during multiple transitions to extreme halophily. We detect active silica encrustment/fossilization of cells but also abiotic biomorphs of varied chemistry. Our work helps circumscribing habitability and calls for cautionary interpretations of morphological biosignatures on Earth and beyond.
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Affiliation(s)
- Jodie Belilla
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France
| | - David Moreira
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France
| | - Ludwig Jardillier
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France
| | - Guillaume Reboul
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France
| | - Karim Benzerara
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, CNRS, Sorbonne Université, Muséum National d'Histoire Naturelle, Paris, France
| | | | - Paola Bertolino
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France
| | | | - Purificación López-García
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, Université Paris-Saclay, AgroParisTech, Orsay, France.
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14
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Aerts JW, van Spanning RJM, Flahaut J, Molenaar D, Bland PA, Genge MJ, Ehrenfreund P, Martins Z. Microbial Communities in Sediments From Four Mildly Acidic Ephemeral Salt Lakes in the Yilgarn Craton (Australia) - Terrestrial Analogs to Ancient Mars. Front Microbiol 2019; 10:779. [PMID: 31133990 PMCID: PMC6512757 DOI: 10.3389/fmicb.2019.00779] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 03/27/2019] [Indexed: 11/24/2022] Open
Abstract
The Yilgarn Craton in Australia has a large number of naturally occurring shallow ephemeral lakes underlain by a dendritic system of paleodrainage channels. Processes like evaporation, flooding, erosion, as well as inflow of saline, often acidic and ion-rich groundwater contribute to the (dynamic) nature of the lakes and the composition of the sediments. The region has previously been described as an analog environment for early Mars due to its geological and geophysical similarities. Here, we investigated sediment samples of four lake environments aimed at getting a fundamental understanding of the native microbial communities and the mineralogical and (bio)chemical composition of the sediments they are associated with. The dominant mineral phases in the sediments were quartz, feldspars and amphiboles, while halite and gypsum were the only evaporites detected. Element analysis revealed a rich and complex image, in which silicon, iron, and aluminum were the dominant ions, but relative high concentrations of trace elements such as strontium, chromium, zirconium, and barium were also found. The concentrations of organic carbon, nitrogen, and phosphorus were generally low. 16S amplicon sequencing on the Illumina platform showed the presence of diverse microbial communities in all four lake environments. We found that most of the communities were dominated by extremely halophilic Archaea of the Halobacteriaceae family. The dynamic nature of these lakes appears to influence the biological, biochemical, and geological components of the ecosystem to a large effect. Inter- and intra-lake variations in the distributions of microbial communities were significant, and could only to a minor degree be explained by underlying environmental conditions. The communities are likely significantly influenced by small scale local effects caused by variations in geological settings and dynamic interactions caused by aeolian transport and flooding and evaporation events.
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Affiliation(s)
- Joost W Aerts
- Department of Molecular Cell Biology, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Rob J M van Spanning
- Department of Molecular Cell Biology, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Jessica Flahaut
- Centre de Recherches Pétrographiques et Géochimiques, Centre National de la Recherche Scientifique/Université de Lorraine, Vandœuvre-lès-Nancy, France
| | - Douwe Molenaar
- Department of Molecular Cell Biology, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Phil A Bland
- Department of Applied Geology, Curtin University, Perth, WA, Australia
| | - Matt J Genge
- Department of Earth Science and Engineering, Faculty of Engineering, Imperial College London, London, United Kingdom
| | - Pascale Ehrenfreund
- Leiden Observatory, Leiden University, Leiden, Netherlands.,Space Policy Institute, Elliott School of International Affairs, George Washington University, Washington, DC, United States
| | - Zita Martins
- Centro de Química-Física Molecular-Institute of Nanoscience and Nanotechnology (CQFM-IN), Institute for Bioengineering and Biosciences (iBB), Departamento de Engenharia Química, Instituto Superior Técnico (IST), Universidade de Lisboa, Lisbon, Portugal
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15
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A thiotrophic microbial community in an acidic brine lake in Northern Chile. Antonie van Leeuwenhoek 2018; 111:1403-1419. [PMID: 29748902 DOI: 10.1007/s10482-018-1087-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 04/12/2018] [Indexed: 10/16/2022]
Abstract
The endorheic basins of the Northern Chilean Altiplano contain saline lakes and salt flats. Two of the salt flats, Gorbea and Ignorado, have high acidic brines. The causes of the local acidity have been attributed to the occurrence of volcanic native sulfur, the release of sulfuric acid by oxidation, and the low buffering capacity of the rocks in the area. Understanding the microbial community composition and available energy in this pristine ecosystem is relevant in determining the origin of the acidity and in supporting the rationale of conservation policies. Besides, a comparison between similar systems in Australia highlights key microbial components and specific ones associated with geological settings and environmental conditions. Sediment and water samples from the Salar de Gorbea were collected, physicochemical parameters measured and geochemical and molecular biological analyses performed. A low diversity microbial community was observed in brines and sediments dominated by Actinobacteria, Algae, Firmicutes and Proteobacteria. Most of the constituent genera have been reported to be either sulfur oxidizing microorganisms or ones having the potential for sulfur oxidation given available genomic data and information drawn from the literature on cultured relatives. In addition, a link between sulfur oxidation and carbon fixation was observed. In contrast, to acid mine drainage communities, Gorbea microbial diversity is mainly supported by chemolithoheterotrophic, facultative chemolithoautotrophic and oligotrophic sulfur oxidizing populations indicating that microbial activity should also be considered as a causative agent of local acidity.
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16
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Microbiomes in extremely acidic environments: functionalities and interactions that allow survival and growth of prokaryotes at low pH. Curr Opin Microbiol 2018; 43:139-147. [PMID: 29414445 DOI: 10.1016/j.mib.2018.01.011] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 01/17/2018] [Accepted: 01/20/2018] [Indexed: 11/23/2022]
Abstract
Extremely acidic environments have global distribution and can have natural or, increasingly, anthropogenic origins. Extreme acidophiles grow optimally at pH 3 or less, have multiple strategies for tolerating stresses that accompany high levels of acidity and are scattered in all three domains of the tree of life. Metagenomic studies have expanded knowledge of the diversity of extreme acidophile communities, their ecological networks and their metabolic potentials, both confirmed and inferred. High resolution compositional and functional profiling of these microbiomes have begun to reveal spatial diversity patterns at global, regional, local, zonal and micro-scales. Future integration of genomic and other meta-omic data will offer new opportunities to utilize acidic microbiomes and to engineer beneficial interactions within them in biotechnologies.
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17
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Zaikova E, Benison KC, Mormile MR, Johnson SS. Microbial communities and their predicted metabolic functions in a desiccating acid salt lake. Extremophiles 2018; 22:367-379. [PMID: 29350297 DOI: 10.1007/s00792-018-1000-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 01/02/2018] [Indexed: 11/30/2022]
Abstract
The waters of Lake Magic in Western Australia are among the most geochemically extreme on Earth. This ephemeral saline lake is characterized by pH as low as 1.6 salinity as high as 32% total dissolved solids, and unusually complex geochemistry, including extremely high concentrations of aluminum, silica, and iron. We examined the microbial composition and putative function in this extreme acid brine environment by analyzing lake water, groundwater, and sediment samples collected during the austral summer near peak evapoconcentration. Our results reveal that the lake water metagenome, surprisingly, was comprised of mostly eukaryote sequences, particularly fungi and to a lesser extent, green algae. Groundwater and sediment samples were dominated by acidophilic Firmicutes, with eukaryotic community members only detected at low abundances. The lake water bacterial community was less diverse than that in groundwater and sediment, and was overwhelmingly represented by a single OTU affiliated with Salinisphaera. Pathways associated with halotolerance were found in the metagenomes, as were genes associated with biosynthesis of protective carotenoids. During periods of complete desiccation of the lake, we hypothesize that dormancy and entrapment in fluid inclusions in halite crystals may increase long-term survival, leading to the resilience of complex eukaryotes in this extreme environment.
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Affiliation(s)
- Elena Zaikova
- Department of Biology, Georgetown University, Washington, USA
| | - Kathleen C Benison
- Department of Geology and Geography, West Virginia University, Morgantown, USA
| | - Melanie R Mormile
- Department of Biology, Missouri University of Science and Technology, Rolla, USA
| | - Sarah Stewart Johnson
- Department of Biology, Georgetown University, Washington, USA. .,Program on Science, Technology, and International Affairs, Georgetown University, Washington, USA.
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18
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Ren Z, Gao H, Elser JJ, Zhao Q. Microbial functional genes elucidate environmental drivers of biofilm metabolism in glacier-fed streams. Sci Rep 2017; 7:12668. [PMID: 28978929 PMCID: PMC5627277 DOI: 10.1038/s41598-017-13086-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 09/18/2017] [Indexed: 11/09/2022] Open
Abstract
Benthic biofilms in glacier-fed streams harbor diverse microorganisms driving biogeochemical cycles and, consequently, influencing ecosystem-level processes. Benthic biofilms are vulnerable to glacial retreat induced by climate change. To investigate microbial functions of benthic biofilms in glacier-fed streams, we predicted metagenomes from 16s rRNA gene sequence data using PICRUSt and identified functional genes associated with nitrogen and sulfur metabolisms based on KEGG database and explored the relationships between metabolic pathways and abiotic factors in glacier-fed streams in the Tianshan Mountains in Central Asia. Results showed that the distribution of functional genes was mainly associated with glacier area proportion, glacier source proportion, total nitrogen, dissolved organic carbon, and pH. For nitrogen metabolism, the relative abundance of functional genes associated with dissimilatory pathways was higher than those for assimilatory pathways. The relative abundance of functional genes associated with assimilatory sulfate reduction was higher than those involved with the sulfur oxidation system and dissimilatory sulfate reduction. Hydrological factors had more significant correlations with nitrogen metabolism than physicochemical factors and anammox was the most sensitive nitrogen cycling pathway responding to variation of the abiotic environment in these glacial-fed streams. In contrast, sulfur metabolism pathways were not sensitive to variations of abiotic factors in these systems.
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Affiliation(s)
- Ze Ren
- Flathead Lake Biological Station, University of Montana, Polson, MT, 59860, USA
| | - Hongkai Gao
- State Key Laboratory of Cryosheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China. .,School of Life Sciences, Arizona State University, Tempe, AZ, 85281, USA. .,School of Geography and Planing, Sun Yat-Sen University, Guangzhou, 510275, China.
| | - James J Elser
- Flathead Lake Biological Station, University of Montana, Polson, MT, 59860, USA
| | - Qiudong Zhao
- State Key Laboratory of Cryosheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
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19
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Interpreting Microbial Biosynthesis in the Genomic Age: Biological and Practical Considerations. Mar Drugs 2017; 15:md15060165. [PMID: 28587290 PMCID: PMC5484115 DOI: 10.3390/md15060165] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 05/22/2017] [Accepted: 05/31/2017] [Indexed: 02/06/2023] Open
Abstract
Genome mining has become an increasingly powerful, scalable, and economically accessible tool for the study of natural product biosynthesis and drug discovery. However, there remain important biological and practical problems that can complicate or obscure biosynthetic analysis in genomic and metagenomic sequencing projects. Here, we focus on limitations of available technology as well as computational and experimental strategies to overcome them. We review the unique challenges and approaches in the study of symbiotic and uncultured systems, as well as those associated with biosynthetic gene cluster (BGC) assembly and product prediction. Finally, to explore sequencing parameters that affect the recovery and contiguity of large and repetitive BGCs assembled de novo, we simulate Illumina and PacBio sequencing of the Salinispora tropica genome focusing on assembly of the salinilactam (slm) BGC.
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20
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Haferburg G, Gröning JAD, Schmidt N, Kummer NA, Erquicia JC, Schlömann M. Microbial diversity of the hypersaline and lithium-rich Salar de Uyuni, Bolivia. Microbiol Res 2017; 199:19-28. [PMID: 28454706 DOI: 10.1016/j.micres.2017.02.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 02/25/2017] [Indexed: 10/20/2022]
Abstract
Salar de Uyuni, situated in the Southwest of the Bolivian Altiplano, is the largest salt flat on Earth. Brines of this athalassohaline hypersaline environment are rich in lithium and boron. Due to the ever- increasing commodity demand, the industrial exploitation of brines for metal recovery from the world's biggest lithium reservoir is likely to increase substantially in the near future. Studies on the composition of halophilic microbial communities in brines of the salar have not been published yet. Here we report for the first time on the prokaryotic diversity of four brine habitats across the salar. The brine is characterized by salinity values between 132 and 177 PSU, slightly acidic to near-neutral pH and lithium and boron concentrations of up to 2.0 and 1.4g/L, respectively. Community analysis was performed after sequencing the V3-V4 region of the 16S rRNA genes employing the Illumina MiSeq technology. The mothur software package was used for sequence processing and data analysis. Metagenomic analysis revealed the occurrence of an exclusively archaeal community comprising 26 halobacterial genera including only recently identified genera like Halapricum, Halorubellus and Salinarchaeum. Despite the high diversity of the halobacteria-dominated community in sample P3 (Shannon-Weaver index H'=3.12 at 3% OTU cutoff) almost 40% of the Halobacteriaceae-assigned sequences could not be classified on the genus level under stringent filtering conditions. Even if the limited taxonomic resolution of the V3-V4 region for halobacteria is considered, it seems likely to discover new, hitherto undescribed genera of the family halobacteriaceae in this particular habitat of Salar de Uyuni in future.
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Affiliation(s)
- Götz Haferburg
- Interdisciplinary Ecological Center, Environmental Microbiology Group, TU Bergakademie Freiberg, Leipziger Strasse 29, 09599 Freiberg, Germany.
| | | | - Nadja Schmidt
- Institute of Hydrogeology and Environmental Geology, TU Bergakademie Freiberg, Gustav-Zeuner-Straße 12, 09599 Freiberg, Germany
| | - Nicolai-Alexeji Kummer
- Institute of Hydrogeology and Environmental Geology, TU Bergakademie Freiberg, Gustav-Zeuner-Straße 12, 09599 Freiberg, Germany
| | | | - Michael Schlömann
- Interdisciplinary Ecological Center, Environmental Microbiology Group, TU Bergakademie Freiberg, Leipziger Strasse 29, 09599 Freiberg, Germany
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21
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Draft Genome Sequence of the Acidophilic, Halotolerant, and Iron/Sulfur-Oxidizing Acidihalobacter prosperus DSM 14174 (Strain V6). GENOME ANNOUNCEMENTS 2017; 5:5/3/e01469-16. [PMID: 28104654 PMCID: PMC5255921 DOI: 10.1128/genomea.01469-16] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The principal genomic features of Acidihalobacter prosperus DSM 14174 (strain V6) are presented here. This is a mesophilic, halotolerant, and iron/sulfur-oxidizing acidophile that was isolated from seawater at Vulcano, Italy. It has potential for use in biomining applications in regions where high salinity exists in the source water and ores.
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22
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Santiago-Rodriguez TM, Fornaciari G, Luciani S, Dowd SE, Toranzos GA, Marota I, Cano RJ. Taxonomic and predicted metabolic profiles of the human gut microbiome in pre-Columbian mummies. FEMS Microbiol Ecol 2016; 92:fiw182. [PMID: 27559027 DOI: 10.1093/femsec/fiw182] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/19/2016] [Indexed: 11/15/2022] Open
Abstract
Characterization of naturally mummified human gut remains could potentially provide insights into the preservation and evolution of commensal and pathogenic microorganisms, and metabolic profiles. We characterized the gut microbiome of two pre-Columbian Andean mummies dating to the 10-15th centuries using 16S rRNA gene high-throughput sequencing and metagenomics, and compared them to a previously characterized gut microbiome of an 11th century AD pre-Columbian Andean mummy. Our previous study showed that the Clostridiales represented the majority of the bacterial communities in the mummified gut remains, but that other microbial communities were also preserved during the process of natural mummification, as shown with the metagenomics analyses. The gut microbiome of the other two mummies were mainly comprised by Clostridiales or Bacillales, as demonstrated with 16S rRNA gene amplicon sequencing, many of which are facultative anaerobes, possibly consistent with the process of natural mummification requiring low oxygen levels. Metagenome analyses showed the presence of other microbial groups that were positively or negatively correlated with specific metabolic profiles. The presence of sequences similar to both Trypanosoma cruzi and Leishmania donovani could suggest that these pathogens were prevalent in pre-Columbian individuals. Taxonomic and functional profiling of mummified human gut remains will aid in the understanding of the microbial ecology of the process of natural mummification.
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Affiliation(s)
- Tasha M Santiago-Rodriguez
- Center for Applications in Biotechnology, California Polytechnic State University, San Luis Obispo, CA 93407, USA Department of Biology, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| | - Gino Fornaciari
- Department of Translational Research on New Technologies in Medicine and Surgery, Division of Paleopathology, University of Pisa, Pisa 56126, Italy Center for Anthropological, Paleopathological and Historical Studies of the Sardinian and Mediterranean Populations, Department of Biomedical Sciences, University of Sassari, Sassari 07100, Italy
| | - Stefania Luciani
- Laboratory of Molecular Archaeo-Anthropology/ancient DNA, School of Biosciences and Veterinary Medicine, University of Camerino, Camerino 62032, Italy
| | - Scot E Dowd
- Molecular Research LP (MR DNA), Shallowater, Texas 79363, USA
| | - Gary A Toranzos
- Department of Biology, University of Puerto Rico, Julio Garcia Diaz Building, San Juan 00931, Puerto Rico
| | - Isolina Marota
- Laboratory of Molecular Archaeo-Anthropology/ancient DNA, School of Biosciences and Veterinary Medicine, University of Camerino, Camerino 62032, Italy
| | - Raul J Cano
- Center for Applications in Biotechnology, California Polytechnic State University, San Luis Obispo, CA 93407, USA Department of Biology, California Polytechnic State University, San Luis Obispo, CA 93407, USA
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23
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Ruecker A, Schröder C, Byrne J, Weigold P, Behrens S, Kappler A. Geochemistry and Mineralogy of Western Australian Salt Lake Sediments: Implications for Meridiani Planum on Mars. ASTROBIOLOGY 2016; 16:525-538. [PMID: 27258848 DOI: 10.1089/ast.2015.1429] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
UNLABELLED Hypersaline lakes are characteristic for Western Australia and display a rare combination of geochemical and mineralogical properties that make these lakes potential analogues for past conditions on Mars. In our study, we focused on the geochemistry and mineralogy of Lake Orr and Lake Whurr. While both lakes are poor in organic carbon (<1%), the sediments' pH values differ and range from 3.8 to 4.8 in Lake Orr and from 5.4 to 6.3 in Lake Whurr sediments. Lake Whurr sediments were dominated by orange and red sediment zones in which the main Fe minerals were identified as hematite, goethite, and tentatively jarosite and pyrite. Lake Orr was dominated by brownish and blackish sediments where the main Fe minerals were goethite and another paramagnetic Fe(III)-phase that could not be identified. Furthermore, a likely secondary Fe(II)-phase was observed in Lake Orr sediments. The mineralogy of these two salt lakes in the sampling area is strongly influenced by events such as flooding, evaporation, and desiccation, processes that explain at least to some extent the observed differences between Lake Orr and Lake Whurr. The iron mineralogy of Lake Whurr sediments and the high salinity make this lake a suitable analogue for Meridiani Planum on Mars, and in particular the tentative identification of pyrite in Lake Whurr sediments has implications for the interpretation of the Fe mineralogy of Meridiani Planum sediments. KEY WORDS Western Australia-Salt lakes-Jarosite-Hematite-Pyrite-Mars analogue. Astrobiology 16, 525-538.
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Affiliation(s)
- A Ruecker
- 1 Geomicrobiology, Center for Applied Geosciences, University of Tübingen , Tübingen, Germany
| | - C Schröder
- 2 Biological and Environmental Sciences, School of Natural Sciences, University of Stirling , Stirling, Scotland, UK
| | - J Byrne
- 1 Geomicrobiology, Center for Applied Geosciences, University of Tübingen , Tübingen, Germany
| | - P Weigold
- 1 Geomicrobiology, Center for Applied Geosciences, University of Tübingen , Tübingen, Germany
| | - S Behrens
- 1 Geomicrobiology, Center for Applied Geosciences, University of Tübingen , Tübingen, Germany
| | - A Kappler
- 1 Geomicrobiology, Center for Applied Geosciences, University of Tübingen , Tübingen, Germany
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Zhang X, Niu J, Liang Y, Liu X, Yin H. Metagenome-scale analysis yields insights into the structure and function of microbial communities in a copper bioleaching heap. BMC Genet 2016; 17:21. [PMID: 26781463 PMCID: PMC4717592 DOI: 10.1186/s12863-016-0330-4] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 01/13/2016] [Indexed: 01/18/2023] Open
Abstract
Background Metagenomics allows us to acquire the potential resources from both cultivatable and uncultivable microorganisms in the environment. Here, shotgun metagenome sequencing was used to investigate microbial communities from the surface layer of low grade copper tailings that were industrially bioleached at the Dexing Copper Mine, China. A bioinformatics analysis was further performed to elucidate structural and functional properties of the microbial communities in a copper bioleaching heap. Results Taxonomic analysis revealed unexpectedly high microbial biodiversity of this extremely acidic environment, as most sequences were phylogenetically assigned to Proteobacteria, while Euryarchaeota-related sequences occupied little proportion in this system, assuming that Archaea probably played little role in the bioleaching systems. At the genus level, the microbial community in mineral surface-layer was dominated by the sulfur- and iron-oxidizing acidophiles such as Acidithiobacillus-like populations, most of which were A. ferrivorans-like and A. ferrooxidans-like groups. In addition, Caudovirales were the dominant viral type observed in this extremely environment. Functional analysis illustrated that the principal participants related to the key metabolic pathways (carbon fixation, nitrogen metabolism, Fe(II) oxidation and sulfur metabolism) were mainly identified to be Acidithiobacillus-like, Thiobacillus-like and Leptospirillum-like microorganisms, indicating their vital roles. Also, microbial community harbored certain adaptive mechanisms (heavy metal resistance, low pH adaption, organic solvents tolerance and detoxification of hydroxyl radicals) as they performed their functions in the bioleaching system. Conclusion Our study provides several valuable datasets for understanding the microbial community composition and function in the surface-layer of copper bioleaching heap. Electronic supplementary material The online version of this article (doi:10.1186/s12863-016-0330-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xian Zhang
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China. .,Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, China.
| | - Jiaojiao Niu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China. .,Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, China.
| | - Yili Liang
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China. .,Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, China.
| | - Xueduan Liu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China. .,Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, China.
| | - Huaqun Yin
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China. .,Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, China.
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