1
|
Skoog EJ, Bosak T. Predicted metabolic roles and stress responses provide insights into candidate phyla Hydrogenedentota and Sumerlaeota as members of the rare biosphere in biofilms from various environments. ENVIRONMENTAL MICROBIOLOGY REPORTS 2024; 16:e13228. [PMID: 38192240 PMCID: PMC10866078 DOI: 10.1111/1758-2229.13228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 12/11/2023] [Indexed: 01/10/2024]
Abstract
Pustular mats from Shark Bay, Western Australia, host complex microbial communities bound within an organic matrix. These mats harbour many poorly characterized organisms with low relative abundances (<1%), such as candidate phyla Hydrogenedentota and Sumerlaeota. Here, we aim to constrain the metabolism and physiology of these candidate phyla by analyzing two representative metagenome-assembled genomes (MAGs) from a pustular mat. Metabolic reconstructions of these MAGs suggest facultatively anaerobic, chemoorganotrophic lifestyles of both organisms and predict that both MAGs can metabolize a diversity of carbohydrate substrates. Ca. Sumerlaeota possesses genes involved in degrading chitin, cellulose and other polysaccharides, while Ca. Hydrogenedentota can metabolize cellulose derivatives in addition to glycerol, fatty acids and phosphonates. Both Ca. phyla can respond to nitrosative stress and participate in nitrogen metabolism. Metabolic comparisons of MAGs from Shark Bay and those from various polyextreme environments (i.e., hot springs, hydrothermal vents, subsurface waters, anaerobic digesters, etc.) reveal similar metabolic capabilities and adaptations to hypersalinity, oxidative stress, antibiotics, UV radiation, nitrosative stress, heavy metal toxicity and life in surface-attached communities. These adaptations and capabilities may account for the widespread nature of these organisms and their contributions to biofilm communities in a range of extreme surface and subsurface environments.
Collapse
Affiliation(s)
- Emilie J. Skoog
- Department of Earth, Atmospheric and Planetary SciencesMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
- Integrative Oceanography DivisionScripps Institution of Oceanography, UC San DiegoLa JollaCaliforniaUSA
| | - Tanja Bosak
- Department of Earth, Atmospheric and Planetary SciencesMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
| |
Collapse
|
2
|
Garuglieri E, Marasco R, Odobel C, Chandra V, Teillet T, Areias C, Sánchez-Román M, Vahrenkamp V, Daffonchio D. Searching for microbial contribution to micritization of shallow marine sediments. Environ Microbiol 2024; 26:e16573. [PMID: 38217094 DOI: 10.1111/1462-2920.16573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 12/21/2023] [Indexed: 01/15/2024]
Abstract
Micritization is an early diagenetic process that gradually alters primary carbonate sediment grains through cycles of dissolution and reprecipitation of microcrystalline calcite (micrite). Typically observed in modern shallow marine environments, micritic textures have been recognized as a vital component of storage and flow in hydrocarbon reservoirs, attracting scientific and economic interests. Due to their endolithic activity and the ability to promote nucleation and reprecipitation of carbonate crystals, microorganisms have progressively been shown to be key players in micritization, placing this process at the boundary between the geological and biological realms. However, published research is mainly based on geological and geochemical perspectives, overlooking the biological and ecological complexity of microbial communities of micritized sediments. In this paper, we summarize the state-of-the-art and research gaps in micritization from a microbial ecology perspective. Since a growing body of literature successfully applies in vitro and in situ 'fishing' strategies to unveil elusive microorganisms and expand our knowledge of microbial diversity, we encourage their application to the study of micritization. By employing these strategies in micritization research, we advocate promoting an interdisciplinary approach/perspective to identify and understand the overlooked/neglected microbial players and key pathways governing this phenomenon and their ecology/dynamics, reshaping our comprehension of this process.
Collapse
Affiliation(s)
- Elisa Garuglieri
- Red Sea Research Center, Division of Biological Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Ramona Marasco
- Red Sea Research Center, Division of Biological Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Charlene Odobel
- Red Sea Research Center, Division of Biological Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Viswasanthi Chandra
- Ali I. Al-Naimi Petroleum Engineering Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Thomas Teillet
- Ali I. Al-Naimi Petroleum Engineering Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Camila Areias
- Department of Earth Sciences, Faculty of Science, Vrije Universiteit, Amsterdam, the Netherlands
| | - Mónica Sánchez-Román
- Department of Earth Sciences, Faculty of Science, Vrije Universiteit, Amsterdam, the Netherlands
| | - Volker Vahrenkamp
- Ali I. Al-Naimi Petroleum Engineering Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Daniele Daffonchio
- Red Sea Research Center, Division of Biological Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| |
Collapse
|
3
|
Reid RP, Suosaari EP, Oehlert AM, Pollier CGL, Dupraz C. Microbialite Accretion and Growth: Lessons from Shark Bay and the Bahamas. ANNUAL REVIEW OF MARINE SCIENCE 2024; 16:487-511. [PMID: 38231736 DOI: 10.1146/annurev-marine-021423-124637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Microbialites provide geological evidence of one of Earth's oldest ecosystems, potentially recording long-standing interactions between coevolving life and the environment. Here, we focus on microbialite accretion and growth and consider how environmental and microbial forces that characterize living ecosystems in Shark Bay and the Bahamas interact to form an initial microbialite architecture, which in turn establishes distinct evolutionary pathways. A conceptual three-dimensional model is developed for microbialite accretion that emphasizes the importance of a dynamic balance between extrinsic and intrinsic factors in determining the initial architecture. We then explore how early taphonomic and diagenetic processes modify the initial architecture, culminating in various styles of preservation in the rock record. The timing of lithification of microbial products is critical in determining growth patterns and preservation potential. Study results have shown that all microbialites are not created equal; the unique evolutionary history of an individual microbialite matters.
Collapse
Affiliation(s)
- R Pamela Reid
- Department of Marine Geosciences, Rosenstiel School of Marine, Atmospheric, and Earth Science, University of Miami, Miami, Florida, USA; , ,
- Bahamas Marine EcoCentre, Miami, Florida, USA;
| | - Erica P Suosaari
- Bahamas Marine EcoCentre, Miami, Florida, USA;
- Department of Mineral Sciences, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
- Bush Heritage Australia, Melbourne, Victoria, Australia
| | - Amanda M Oehlert
- Department of Marine Geosciences, Rosenstiel School of Marine, Atmospheric, and Earth Science, University of Miami, Miami, Florida, USA; , ,
| | - Clément G L Pollier
- Department of Marine Geosciences, Rosenstiel School of Marine, Atmospheric, and Earth Science, University of Miami, Miami, Florida, USA; , ,
| | - Christophe Dupraz
- Department of Geological Sciences, Stockholm University, Stockholm, Sweden;
| |
Collapse
|
4
|
Skoog EJ, Fournier GP, Bosak T. Assessing the Influence of HGT on the Evolution of Stress Responses in Microbial Communities from Shark Bay, Western Australia. Genes (Basel) 2023; 14:2168. [PMID: 38136990 PMCID: PMC10742547 DOI: 10.3390/genes14122168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 11/27/2023] [Accepted: 11/29/2023] [Indexed: 12/24/2023] Open
Abstract
Pustular microbial mats in Shark Bay, Western Australia, are modern analogs of microbial systems that colonized peritidal environments before the evolution of complex life. To understand how these microbial communities evolved to grow and metabolize in the presence of various environmental stresses, the horizontal gene transfer (HGT) detection tool, MetaCHIP, was used to identify the horizontal transfer of genes related to stress response in 83 metagenome-assembled genomes from a Shark Bay pustular mat. Subsequently, maximum-likelihood phylogenies were constructed using these genes and their most closely related homologs from other environments in order to determine the likelihood of these HGT events occurring within the pustular mat. Phylogenies of several stress-related genes-including those involved in response to osmotic stress, oxidative stress and arsenic toxicity-indicate a potentially long history of HGT events and are consistent with these transfers occurring outside of modern pustular mats. The phylogeny of a particular osmoprotectant transport gene reveals relatively recent adaptations and suggests interactions between Planctomycetota and Myxococcota within these pustular mats. Overall, HGT phylogenies support a potentially broad distribution in the relative timing of the HGT events of stress-related genes and demonstrate ongoing microbial adaptations and evolution in these pustular mat communities.
Collapse
Affiliation(s)
- Emilie J. Skoog
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; (G.P.F.); (T.B.)
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92037, USA
| | - Gregory P. Fournier
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; (G.P.F.); (T.B.)
| | - Tanja Bosak
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; (G.P.F.); (T.B.)
| |
Collapse
|
5
|
Moore KR, Daye M, Gong J, Williford K, Konhauser K, Bosak T. A review of microbial-environmental interactions recorded in Proterozoic carbonate-hosted chert. GEOBIOLOGY 2023; 21:3-27. [PMID: 36268586 PMCID: PMC10092529 DOI: 10.1111/gbi.12527] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 09/14/2022] [Accepted: 09/19/2022] [Indexed: 06/16/2023]
Abstract
The record of life during the Proterozoic is preserved by several different lithologies, but two in particular are linked both spatially and temporally: chert and carbonate. These lithologies capture a snapshot of dominantly peritidal environments during the Proterozoic. Early diagenetic chert preserves some of the most exceptional Proterozoic biosignatures in the form of microbial body fossils and mat textures. This fossiliferous and kerogenous chert formed in shallow marine environments, where chert nodules, layers, and lenses are often surrounded by and encased within carbonate deposits that themselves often contain kerogen and evidence of former microbial mats. Here, we review the record of biosignatures preserved in peritidal Proterozoic chert and chert-hosting carbonate and discuss this record in the context of experimental and environmental studies that have begun to shed light on the roles that microbes and organic compounds may have played in the formation of these deposits. Insights gained from these studies suggest temporal trends in microbial-environmental interactions and place new constraints on past environmental conditions, such as the concentration of silica in Proterozoic seawater, interactions among organic compounds and cations in seawater, and the influence of microbial physiology and biochemistry on selective preservation by silicification.
Collapse
Affiliation(s)
- Kelsey R. Moore
- Division of Geological and Planetary SciencesCalifornia Institute of TechnologyPasadenaCaliforniaUSA
| | - Mirna Daye
- Department of Earth, Atmospheric and Planetary SciencesMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
| | - Jian Gong
- Department of Earth, Atmospheric and Planetary SciencesMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
| | | | - Kurt Konhauser
- Department of Earth and Atmospheric SciencesUniversity of AlbertaEdmontonAlbertaCanada
| | - Tanja Bosak
- Department of Earth, Atmospheric and Planetary SciencesMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
| |
Collapse
|
6
|
Plante CJ, Hill-Spanik KM, Emerson R. Inputs don't equal outputs: bacterial microbiomes of the ingesta, gut, and feces of the keystone deposit feeder Ilyanassa obsoleta. FEMS Microbiol Ecol 2022; 99:6887277. [PMID: 36496168 DOI: 10.1093/femsec/fiac152] [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: 04/19/2022] [Revised: 11/22/2022] [Accepted: 12/09/2022] [Indexed: 12/14/2022] Open
Abstract
Bacteria drive energy fluxes and geochemical processes in estuarine sediments. Deposit-feeding invertebrates alter the structure and activity of microbial communities through sediment ingestion, gut passage, and defecation. The eastern mud snail, Ilyanassa obsoleta, is native to estuaries of the northwestern Atlantic, ranging from Nova Scotia, Canada, to Florida in the USA. Given extremely high densities, their deposit-feeding and locomotory activities exert ecological influence on other invertebrates and microbes. Our aim was to characterize the bacterial microbiome of this 'keystone species' and determine how its feeding alters the native bacterial microbiota. We gathered snails from both mudflat and sandflat habitats and collected their fresh fecal pellets in the laboratory. Dissection of these same snails allowed us to compare bacterial assemblages of ingested sediments, shell surfaces, gut sections (esophagus, stomach, intestine), and feces using DNA metabarcoding. Our findings indicate a diverse, resident gut microbiota. The stomach and intestines were dominated by bacteria of the genus Mycoplasma. Comparison of ingesta and feces revealed digestion of several bacterial taxa, introduction of gut residents during passage, in addition to unique bacterial taxa within the feces of unknown provenance. Our results demonstrate that I. obsoleta has the potential to modify microbial community structure in estuarine sediments.
Collapse
Affiliation(s)
- Craig J Plante
- Grice Marine Laboratory, College of Charleston, Charleston, SC 29412, United States
| | | | - Rowan Emerson
- Grice Marine Laboratory, College of Charleston, Charleston, SC 29412, United States
| |
Collapse
|
7
|
Campbell MA, Bauersachs T, Schwark L, Proemse BC, Eberhard RS, Coolen MJL, Grice K. Salinity-driven ecology and diversity changes of heterocytous cyanobacteria in Australian freshwater and coastal-marine microbial mats. Environ Microbiol 2022; 24:6493-6509. [PMID: 36156347 PMCID: PMC10092834 DOI: 10.1111/1462-2920.16225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 09/23/2022] [Indexed: 01/12/2023]
Abstract
N2 -fixing heterocytous cyanobacteria are considered to play a minor role in sustaining coastal microbial mat communities developing under normal marine to hypersaline conditions. Here, we investigated microbial mats growing under different salinities from freshwater mats of Giblin River (Tasmania) to metahaline and hypersaline mats of Shark Bay (Western Australia). Analyses of genetic (rRNA and mRNA) and biological markers (heterocyte glycolipids) revealed an unexpectedly large diversity of heterocytous cyanobacteria in all the studied microbial mat communities. It was observed that the taxonomic distribution as well as abundance of cyanobacteria is strongly affected by salinity. Low salinity favoured the presence of heterocytous cyanobacteria in freshwater mats, while mats thriving in higher salinities mainly supported the growth unicellular and filamentous non-heterocytous genera. However, even though mRNA transcripts derived from heterocytous cyanobacteria were lower in Shark Bay (<6%) microbial mats, functional analyses revealed that these diazotrophs were transcribing a substantial proportion of the genes involved in biofilm formation and nitrogen fixation. Overall, our data reveal an unexpectedly high diversity of heterocytous cyanobacteria (e.g. Calothrix, Scytonema, Nodularia, Gloeotrichia, Stigonema, Fischerella and Chlorogloeopsis) that had yet to be described in metahaline and hypersaline microbial mats from Shark Bay and that they play a vital role in sustaining the ecosystem functioning of coastal-marine microbial mat systems.
Collapse
Affiliation(s)
- Matthew A Campbell
- Western Australian Organic and Isotope Geochemistry Centre, School of Earth and Planetary Sciences, Curtin University, Perth, Western Australia, Australia
| | - Thorsten Bauersachs
- Institute of Geosciences, Organic Geochemistry Group, Christian-Albrechts-University, Kiel, Germany
| | - Lorenz Schwark
- Western Australian Organic and Isotope Geochemistry Centre, School of Earth and Planetary Sciences, Curtin University, Perth, Western Australia, Australia.,Institute of Geosciences, Organic Geochemistry Group, Christian-Albrechts-University, Kiel, Germany
| | - Bernadette C Proemse
- Institute for Marine and Antarctic Studies, University of Tasmania, Battery Point, Tasmania, Australia
| | - Rolan S Eberhard
- Natural and Cultural Heritage Division, Department of Primary Industries Parks, Water and Environment, Hobart, Tasmania, Australia
| | - Marco J L Coolen
- Western Australian Organic and Isotope Geochemistry Centre, School of Earth and Planetary Sciences, Curtin University, Perth, Western Australia, Australia
| | - Kliti Grice
- Western Australian Organic and Isotope Geochemistry Centre, School of Earth and Planetary Sciences, Curtin University, Perth, Western Australia, Australia
| |
Collapse
|
8
|
Nguyen STT, Vardeh DP, Nelson TM, Pearson LA, Kinsela AS, Neilan BA. Bacterial community structure and metabolic potential in microbialite-forming mats from South Australian saline lakes. GEOBIOLOGY 2022; 20:546-559. [PMID: 35312212 PMCID: PMC9311741 DOI: 10.1111/gbi.12489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 12/28/2021] [Accepted: 01/28/2022] [Indexed: 06/14/2023]
Abstract
Microbialites are sedimentary rocks created in association with benthic microorganisms. While they harbour complex microbial communities, Cyanobacteria perform critical roles in sediment stabilisation and accretion. Microbialites have been described from permanent and ephemeral saline lakes in South Australia; however, the microbial communities that generate and inhabit these biogeological structures have not been studied in detail. To address this knowledge gap, we investigated the composition, diversity and metabolic potential of bacterial communities from different microbialite-forming mats and surrounding sediments in five South Australian saline coastal lakes using 16S rRNA gene sequencing and predictive metagenome analyses. While Proteobacteria and Bacteroidetes were the dominant phyla recovered from the mats and sediments, Cyanobacteria were significantly more abundant in the mat samples. Interestingly, at lower taxonomic levels, the mat communities were vastly different across the five lakes. Comparative analysis of putative mat and sediment metagenomes via PICRUSt2 revealed important metabolic pathways driving the process of carbonate precipitation, including cyanobacterial oxygenic photosynthesis, ureolysis and nitrogen fixation. These pathways were highly conserved across the five examined lakes, although they appeared to be performed by distinct groups of bacterial taxa found in each lake. Stress response, quorum sensing and circadian clock were other important pathways predicted by the in silico metagenome analysis. The enrichment of CRISPR/Cas and phage shock associated genes in these cyanobacteria-rich communities suggests that they may be under selective pressure from viral infection. Together, these results highlight that a very stable ecosystem function is maintained by distinctly different communities in microbialite-forming mats in the five South Australian lakes and reinforce the concept that 'who' is in the community is not as critical as their net metabolic capacity.
Collapse
Affiliation(s)
- Suong T. T. Nguyen
- School of Environmental and Life SciencesUniversity of NewcastleCallaghanNew South WalesAustralia
| | - David P. Vardeh
- School of Biotechnology and Biomolecular SciencesThe University of New South WalesSydneyNew South WalesAustralia
| | - Tiffanie M. Nelson
- School of Environmental and Life SciencesUniversity of NewcastleCallaghanNew South WalesAustralia
| | - Leanne A. Pearson
- School of Environmental and Life SciencesUniversity of NewcastleCallaghanNew South WalesAustralia
| | - Andrew S. Kinsela
- School of Civil and Environmental EngineeringThe University of New South WalesSydneyNew South WalesAustralia
| | - Brett A. Neilan
- School of Environmental and Life SciencesUniversity of NewcastleCallaghanNew South WalesAustralia
- School of Biotechnology and Biomolecular SciencesThe University of New South WalesSydneyNew South WalesAustralia
| |
Collapse
|
9
|
Skoog EJ, Moore KR, Gong J, Ciccarese D, Momper L, Cutts EM, Bosak T. Metagenomic, (bio)chemical, and microscopic analyses reveal the potential for the cycling of sulfated EPS in Shark Bay pustular mats. ISME COMMUNICATIONS 2022; 2:43. [PMID: 37938726 PMCID: PMC9723792 DOI: 10.1038/s43705-022-00128-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 04/12/2022] [Accepted: 04/27/2022] [Indexed: 05/24/2023]
Abstract
Cyanobacteria and extracellular polymeric substances (EPS) in peritidal pustular microbial mats have a two-billion-year-old fossil record. To understand the composition, production, degradation, and potential role of EPS in modern analogous communities, we sampled pustular mats from Shark Bay, Australia and analyzed their EPS matrix. Biochemical and microscopic analyses identified sulfated organic compounds as major components of mat EPS. Sulfur was more abundant in the unmineralized regions with cyanobacteria and less prevalent in areas that contained fewer cyanobacteria and more carbonate precipitates. Sequencing and assembly of the pustular mat sample resulted in 83 high-quality metagenome-assembled genomes (MAGs). Metagenomic analyses confirmed cyanobacteria as the primary sources of these sulfated polysaccharides. Genes encoding for sulfatases, glycosyl hydrolases, and other enzymes with predicted roles in the degradation of sulfated polysaccharides were detected in the MAGs of numerous clades including Bacteroidetes, Chloroflexi, Hydrogenedentes, Myxococcota, Verrucomicrobia, and Planctomycetes. Measurable sulfatase activity in pustular mats and fresh cyanobacterial EPS confirmed the role of sulfatases in the degradation of sulfated EPS. These findings suggest that the synthesis, modification, and degradation of sulfated polysaccharides influence microbial interactions, carbon cycling, and biomineralization processes within peritidal pustular microbial mats.
Collapse
Affiliation(s)
- Emilie J Skoog
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
| | - Kelsey R Moore
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- California Institute of Technology, Division of Geological and Planetary Sciences, Pasadena, CA, 91125, USA
| | - Jian Gong
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Davide Ciccarese
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Lily Momper
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Exponent, Inc., Pasadena, CA, 91106, USA
| | - Elise M Cutts
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Tanja Bosak
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| |
Collapse
|
10
|
A Cyanobacteria Enriched Layer of Shark Bay Stromatolites Reveals a New Acaryochloris Strain Living in Near Infrared Light. Microorganisms 2022; 10:microorganisms10051035. [PMID: 35630477 PMCID: PMC9144716 DOI: 10.3390/microorganisms10051035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 05/03/2022] [Accepted: 05/05/2022] [Indexed: 12/04/2022] Open
Abstract
The genus Acaryochloris is unique among phototrophic organisms due to the dominance of chlorophyll d in its photosynthetic reaction centres and light-harvesting proteins. This allows Acaryochloris to capture light energy for photosynthesis over an extended spectrum of up to ~760 nm in the near infra-red (NIR) spectrum. Acaryochloris sp. has been reported in a variety of ecological niches, ranging from polar to tropical shallow aquatic sites. Here, we report a new Acarychloris strain isolated from an NIR-enriched stratified microbial layer 4–6 mm under the surface of stromatolite mats located in the Hamelin Pool of Shark Bay, Western Australia. Pigment analysis by spectrometry/fluorometry, flow cytometry and spectral confocal microscopy identifies unique patterns in pigment content that likely reflect niche adaption. For example, unlike the original A. marina species (type strain MBIC11017), this new strain, Acarychloris LARK001, shows little change in the chlorophyll d/a ratio in response to changes in light wavelength, displays a different Fv/Fm response and lacks detectable levels of phycocyanin. Indeed, 16S rRNA analysis supports the identity of the A. marina LARK001 strain as close to but distinct from from the A. marina HICR111A strain first isolated from Heron Island and previously found on the Great Barrier Reef under coral rubble on the reef flat. Taken together, A. marina LARK001 is a new cyanobacterial strain adapted to the stromatolite mats in Shark Bay.
Collapse
|
11
|
Abstract
Here we review the application of molecular biological approaches to mineral precipitation in modern marine microbialites. The review focuses on the nearly two decades of nucleotide sequencing studies of the microbialites of Shark Bay, Australia; and The Bahamas. Molecular methods have successfully characterized the overall community composition of mats, pinpointed microbes involved in key metabolisms, and revealed patterns in the distributions of microbial groups and functional genes. Molecular tools have become widely accessible, and we can now aim to establish firmer links between microbes and mineralization. Two promising future directions include “zooming in” to assess the roles of specific organisms, microbial groups, and surfaces in carbonate biomineralization and “zooming out” to consider broader spans of space and time. A middle ground between the two can include model systems that contain representatives of important microbial groups, processes, and metabolisms in mats and simplify hypothesis testing. These directions will benefit from expanding reference datasets of marine microbes and enzymes and enrichments of representative microbes from mats. Such applications of molecular tools should improve our ability to interpret ancient and modern microbialites and increase the utility of these rocks as long-term recorders of microbial processes and environmental chemistry.
Collapse
|
12
|
Genomic and Functional Variation of the Chlorophyll d-Producing Cyanobacterium Acaryochloris marina. Microorganisms 2022; 10:microorganisms10030569. [PMID: 35336144 PMCID: PMC8949462 DOI: 10.3390/microorganisms10030569] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 03/01/2022] [Accepted: 03/04/2022] [Indexed: 02/01/2023] Open
Abstract
The Chlorophyll d-producing cyanobacterium Acaryochloris marina is widely distributed in marine environments enriched in far-red light, but our understanding of its genomic and functional diversity is limited. Here, we take an integrative approach to investigate A. marina diversity for 37 strains, which includes twelve newly isolated strains from previously unsampled locations in Europe and the Pacific Northwest of North America. A genome-wide phylogeny revealed both that closely related A. marina have migrated within geographic regions and that distantly related A. marina lineages can co-occur. The distribution of traits mapped onto the phylogeny provided evidence of a dynamic evolutionary history of gene gain and loss during A. marina diversification. Ancestral genes that were differentially retained or lost by strains include plasmid-encoded sodium-transporting ATPase and bidirectional NiFe-hydrogenase genes that may be involved in salt tolerance and redox balance under fermentative conditions, respectively. The acquisition of genes by horizontal transfer has also played an important role in the evolution of new functions, such as nitrogen fixation. Together, our results resolve examples in which genome content and ecotypic variation for nutrient metabolism and environmental tolerance have diversified during the evolutionary history of this unusual photosynthetic bacterium.
Collapse
|
13
|
Moore KR, Gong J, Pajusalu M, Skoog EJ, Xu M, Feliz Soto T, Sojo V, Matreux T, Baldes MJ, Braun D, Williford K, Bosak T. A new model for silicification of cyanobacteria in Proterozoic tidal flats. GEOBIOLOGY 2021; 19:438-449. [PMID: 33979014 DOI: 10.1111/gbi.12447] [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: 07/14/2020] [Revised: 04/02/2021] [Accepted: 04/10/2021] [Indexed: 06/12/2023]
Abstract
Microbial fossils preserved by early diagenetic chert provide a window into the Proterozoic biosphere, but seawater chemistry, microbial processes, and the interactions between microbes and the environment that contributed to this preservation are not well constrained. Here, we use fossilization experiments to explore the processes that preserve marine cyanobacterial biofilms by the precipitation of amorphous silica in a seawater medium that is analogous to Proterozoic seawater. These experiments demonstrate that the exceptional silicification of benthic marine cyanobacteria analogous to the oldest diagnostic cyanobacterial fossils requires interactions among extracellular polymeric substances (EPS), photosynthetically induced pH changes, magnesium cations (Mg2+ ), and >70 ppm silica.
Collapse
Affiliation(s)
- Kelsey R Moore
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jian Gong
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Mihkel Pajusalu
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
- Tartu Observatory, University of Tartu, Tõravere, Estonia
| | - Emilie J Skoog
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Megan Xu
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | | | - Victor Sojo
- American Museum of Natural History, New York, NY, USA
- Department of Physics, Ludwig Maximilian University, München, Germany
| | - Thomas Matreux
- Department of Physics, Ludwig Maximilian University, München, Germany
| | - Matthew J Baldes
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Dieter Braun
- Department of Physics, Ludwig Maximilian University, München, Germany
| | - Kenneth Williford
- Jet Propulsion Laboratory, California Institute ofTechnology, Pasadena, CA, USA
| | - Tanja Bosak
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| |
Collapse
|
14
|
Petryshyn VA, Junkins EN, Stamps BW, Bailey JV, Stevenson BS, Spear JR, Corsetti FA. Builders, tenants, and squatters: the origins of genetic material in modern stromatolites. GEOBIOLOGY 2021; 19:261-277. [PMID: 33524239 DOI: 10.1111/gbi.12429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 12/08/2020] [Accepted: 01/14/2021] [Indexed: 06/12/2023]
Abstract
Micro-organisms have long been implicated in the construction of stromatolites. Yet, establishing a microbial role in modern stromatolite growth via molecular analysis is not always straightforward because DNA in stromatolites can have multiple origins. For example, the genomic material could represent the microbes responsible for the construction of the stromatolite (i.e., "builders"), microbes that inhabited the structure after it was built (i.e., "tenants"), or microbes/organic matter that were passively incorporated after construction from the water column or later diagenetic fluids (i.e., "squatters"). Disentangling the role of micro-organisms in stromatolite construction, already difficult in modern systems, becomes more difficult as organic signatures degrade, and their context is obscured. To evaluate our ability to accurately decipher the role of micro-organisms in stromatolite formation in geologically recent settings, 16/18S SSU rRNA gene sequences were analyzed from three systems where the context of growth was well understood: (a) an actively growing stromatolite from a silicic hot spring in Yellowstone National Park, Wyoming, where the construction of the structure is controlled by cyanobacteria; (b) a mixed carbonate and silica precipitate from Little Hot Creek, a hot spring in the Long Valley Caldera of California that has both abiogenic and biogenic components to accretion; and (c) a near-modern lacustrine carbonate stromatolite from Walker Lake, Nevada that is likely abiogenic. In all cases, the largest percentage of recovered DNA sequences, especially when focused on the deeper portions of the structures, belonged to either the tenant or squatter communities, not the actual builders. Once removed from their environmental context, correct interpretation of biology's role in stromatolite morphogenesis was difficult. Because high-throughput genomic analysis may easily lead to incorrect assumptions even in these modern and near-modern structures, caution must be exercised when interpreting micro-organismal involvement in the construction of accretionary structures throughout the rock record.
Collapse
Affiliation(s)
- Victoria A Petryshyn
- Environmental Studies Program, University of Southern California, Los Angeles, CA, USA
| | - Emily N Junkins
- Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, USA
| | - Blake W Stamps
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO, USA
- 711th Human Performance Wing, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, USA
- UES, Inc., Dayton, OH, USA
| | - Jake V Bailey
- Department of Earth Sciences, University of Minnesota, Minneapolis, MN, USA
| | - Bradley S Stevenson
- Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, USA
| | - John R Spear
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO, USA
| | - Frank A Corsetti
- Department of Earth Sciences, University of Southern California, Los Angeles, CA, USA
| |
Collapse
|
15
|
Xue H, Kurokawa M, Ying BW. Correlation between the spatial distribution and colony size was common for monogenetic bacteria in laboratory conditions. BMC Microbiol 2021; 21:114. [PMID: 33858359 PMCID: PMC8051089 DOI: 10.1186/s12866-021-02180-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 03/22/2021] [Indexed: 12/02/2022] Open
Abstract
Background Geographically separated population growth of microbes is a common phenomenon in microbial ecology. Colonies are representative of the morphological characteristics of this structured population growth. Pattern formation by single colonies has been intensively studied, whereas the spatial distribution of colonies is poorly investigated. Results The present study describes a first trial to address the questions of whether and how the spatial distribution of colonies determines the final colony size using the model microorganism Escherichia coli, colonies of which can be grown under well-controlled laboratory conditions. A computational tool for image processing was developed to evaluate colony density, colony size and size variation, and the Voronoi diagram was applied for spatial analysis of colonies with identical space resources. A positive correlation between the final colony size and the Voronoi area was commonly identified, independent of genomic and nutritional differences, which disturbed the colony size and size variation. Conclusions This novel finding of a universal correlation between the spatial distribution and colony size not only indicated the fair distribution of spatial resources for monogenetic colonies growing with identical space resources but also indicated that the initial localization of the microbial colonies decided by chance determined the fate of the subsequent population growth. This study provides a valuable example for quantitative analysis of the complex microbial ecosystems by means of experimental ecology. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-021-02180-8.
Collapse
Affiliation(s)
- Heng Xue
- School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8572, Japan
| | - Masaomi Kurokawa
- School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8572, Japan
| | - Bei-Wen Ying
- School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8572, Japan.
| |
Collapse
|
16
|
Greco C, Andersen DT, Hawes I, Bowles AMC, Yallop ML, Barker G, Jungblut AD. Microbial Diversity of Pinnacle and Conical Microbial Mats in the Perennially Ice-Covered Lake Untersee, East Antarctica. Front Microbiol 2020; 11:607251. [PMID: 33362751 PMCID: PMC7759091 DOI: 10.3389/fmicb.2020.607251] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 11/20/2020] [Indexed: 01/04/2023] Open
Abstract
Antarctic perennially ice-covered lakes provide a stable low-disturbance environment where complex microbially mediated structures can grow. Lake Untersee, an ultra-oligotrophic lake in East Antarctica, has the lake floor covered in benthic microbial mat communities, where laminated organo-sedimentary structures form with three distinct, sympatric morphologies: small, elongated cuspate pinnacles, large complex cones and flat mats. We examined the diversity of prokaryotes and eukaryotes in pinnacles, cones and flat microbial mats using high-throughput sequencing of 16S and 18S rRNA genes and assessed how microbial composition may underpin the formation of these distinct macroscopic mat morphologies under the same environmental conditions. Our analysis identified distinct clustering of microbial communities according to mat morphology. The prokaryotic communities were dominated by Cyanobacteria, Proteobacteria, Verrucomicrobia, Planctomycetes, and Actinobacteria. While filamentous Tychonema cyanobacteria were common in all mat types, Leptolyngbya showed an increased relative abundance in the pinnacle structures only. Our study provides the first report of the eukaryotic community structure of Lake Untersee benthic mats, which was dominated by Ciliophora, Chlorophyta, Fungi, Cercozoa, and Discicristata. The eukaryote richness was lower than for prokaryote assemblages and no distinct clustering was observed between mat morphologies. These findings suggest that cyanobacterial assemblages and potentially other bacteria and eukaryotes may influence structure morphogenesis, allowing distinct structures to form across a small spatial scale.
Collapse
Affiliation(s)
- Carla Greco
- Department of Life Sciences, Natural History Museum, London, United Kingdom.,School of Biological Sciences, University of Bristol, Bristol, United Kingdom
| | - Dale T Andersen
- Carl Sagan Center, SETI Institute, Mountain View, CA, United States
| | - Ian Hawes
- Coastal Marine Field Station, University of Waikato, Tauranga, New Zealand
| | | | - Marian L Yallop
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
| | - Gary Barker
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
| | - Anne D Jungblut
- Department of Life Sciences, Natural History Museum, London, United Kingdom
| |
Collapse
|
17
|
Campbell MA, Grice K, Visscher PT, Morris T, Wong HL, White RA, Burns BP, Coolen MJL. Functional Gene Expression in Shark Bay Hypersaline Microbial Mats: Adaptive Responses. Front Microbiol 2020; 11:560336. [PMID: 33312167 PMCID: PMC7702295 DOI: 10.3389/fmicb.2020.560336] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 10/09/2020] [Indexed: 11/25/2022] Open
Abstract
Microbial mat communities possess extensive taxonomic and functional diversity, which drive high metabolic rates and rapid cycling of major elements. Modern microbial mats occurring in hypersaline environments are considered as analogs to extinct geobiological formations dating back to ∼ 3.5 Gyr ago. Despite efforts to understand the diversity and metabolic potential of hypersaline microbial mats in Shark Bay, Western Australia, there has yet to be molecular analyses at the transcriptional level in these microbial communities. In this study, we generated metatranscriptomes for the first time from actively growing mats comparing the type of mat, as well as the influence of diel and seasonal cycles. We observed that the overall gene transcription is strongly influenced by microbial community structure and seasonality. The most transcribed genes were associated with tackling the low nutrient conditions by the uptake of fatty acids, phosphorus, iron, and nickel from the environment as well as with protective mechanisms against elevated salinity conditions and to prevent build-up of ammonium produced by nitrate reducing microorganisms. A range of pathways involved in carbon, nitrogen, and sulfur cycles were identified in mat metatranscriptomes, with anoxygenic photosynthesis and chemoautotrophy using the Arnon–Buchanan cycle inferred as major pathways involved in the carbon cycle. Furthermore, enrichment of active anaerobic pathways (e.g., sulfate reduction, methanogenesis, Wood–Ljungdahl) in smooth mats corroborates previous metagenomic studies and further advocates the potential of these communities as modern analogs of ancient microbialites.
Collapse
Affiliation(s)
- Matthew A Campbell
- WA-Organic Isotope Geochemistry Centre, The Institute for Geoscience Research, School of Earth and Planetary Sciences, Curtin University, Perth, WA, Australia
| | - Kliti Grice
- WA-Organic Isotope Geochemistry Centre, The Institute for Geoscience Research, School of Earth and Planetary Sciences, Curtin University, Perth, WA, Australia
| | - Pieter T Visscher
- Departments of Marine Sciences and Geoscience, University of Connecticut, Storrs, CT, United States.,Australian Centre for Astrobiology, University of New South Wales, Sydney, NSW, Australia
| | - Therese Morris
- Applied Geology, Curtin University, Perth, WA, Australia
| | - Hon Lun Wong
- Australian Centre for Astrobiology, University of New South Wales, Sydney, NSW, Australia.,School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Richard Allen White
- Australian Centre for Astrobiology, University of New South Wales, Sydney, NSW, Australia.,Plant Pathology, Washington State University, Pullman, WA, United States.,RAW Molecular Systems (RMS) LLC, Spokane, WA, United States
| | - Brendan P Burns
- Australian Centre for Astrobiology, University of New South Wales, Sydney, NSW, Australia.,School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Marco J L Coolen
- WA-Organic Isotope Geochemistry Centre, The Institute for Geoscience Research, School of Earth and Planetary Sciences, Curtin University, Perth, WA, Australia
| |
Collapse
|
18
|
Charlesworth J, Kimyon O, Manefield M, Beloe CJ, Burns BP. Archaea join the conversation: detection of AHL-like activity across a range of archaeal isolates. FEMS Microbiol Lett 2020; 367:5874252. [PMID: 32691824 DOI: 10.1093/femsle/fnaa123] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 07/17/2020] [Indexed: 12/24/2022] Open
Abstract
Quorum sensing is a mechanism of genetic control allowing single cell organisms to coordinate phenotypic response(s) across a local population and is often critical for ecosystem function. Although quorum sensing has been extensively studied in bacteria comparatively less is known about this mechanism in Archaea. Given the growing significance of Archaea in both natural and anthropogenic settings, it is important to delineate how widespread this phenomenon of signaling is in this domain. Employing a plasmid-based AHL biosensor in conjunction with thin-layer chromatography (TLC), the present study screened a broad range of euryarchaeota isolates for potential signaling activity. Data indicated the presence of 11 new Archaeal isolates with AHL-like activity against the LuxR-based AHL biosensor, including for the first time putative AHL activity in a thermophile. The presence of multiple signals and distinct changes between growth phases were also shown via TLC. Multiple signal molecules were detected using TLC in Haloferax mucosum, Halorubrum kocurii, Natronococcus occultus and Halobacterium salinarium. The finding of multiple novel signal producers suggests the potential for quorum sensing to play an important role not only in the regulation of complex phenotypes within Archaea but the potential for cross-talk with bacterial systems.
Collapse
Affiliation(s)
- James Charlesworth
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, Australia.,Australian Centre for Astrobiology, University of New South Wales Sydney, 2052, Australia
| | - Onder Kimyon
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, Australia.,School of Civil and Environmental Engineering, The University of New South Wales, Sydney, 2052 Australia
| | - Michael Manefield
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, Australia.,School of Civil and Environmental Engineering, The University of New South Wales, Sydney, 2052 Australia.,School of Chemical Engineering, The University of New South Wales, Sydney, 2052, Australia
| | - Charlotte J Beloe
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, Australia.,Australian Centre for Astrobiology, University of New South Wales Sydney, 2052, Australia
| | - Brendan P Burns
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, Australia.,Australian Centre for Astrobiology, University of New South Wales Sydney, 2052, Australia
| |
Collapse
|
19
|
Momper L, Hu E, Moore KR, Skoog EJ, Tyler M, Evans AJ, Bosak T. Metabolic versatility in a modern lineage of cyanobacteria from terrestrial hot springs. Free Radic Biol Med 2019; 140:224-232. [PMID: 31163257 DOI: 10.1016/j.freeradbiomed.2019.05.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 05/14/2019] [Accepted: 05/31/2019] [Indexed: 01/23/2023]
Abstract
The extent of oxygenated environments on the early Earth was much lower than today, and cyanobacteria were critical players in Earth's shift from widespread anoxia to oxygenated surface environments. Extant cyanobacteria that aggregate into cones, tufts and ridges are used to understand the long record of photosynthesis and microbe-mineral interactions during times when oxygen was much lower, i.e., the Archean and the Proterozoic. To better understand the metabolic versatility and physiological properties of these organisms, we examined publicly available genomes of cyanobacteria from modern terrestrial hydrothermal systems and a newly sequenced genome of a cyanobacterium isolated from conical and ridged microbialites that grow in occasionally sulfidic hydrothermal springs in Yellowstone National Park, USA. Phylogenomic analyses reveal that cyanobacteria from globally distributed terrestrial and shallow marine hydrothermal systems form a monophyletic clade within the Cyanobacteria phylum. Comparative genomics of this clade reveals the genetic capacity for oxygenic photosynthesis that uses photosystems I and II, and anoxygenic photosynthesis that uses a putative sulfide quinone reductase to oxidize sulfide and bypass photosystem II. Surprisingly large proportions of the newly sequenced genome from Yellowstone National Park are also dedicated to secondary metabolite production (15.1-15.6%), of which ∼6% can be attributed to antibiotic production and resistance genes. All this may be advantageous to benthic, mat-forming photosynthesizers that have to compete for light and nutrients in sporadically or permanently sulfidic environments, and may have also improved the tolerance of ancient counterparts of these cyanobacteria to sulfidic conditions in benthic communities that colonized the coastal margins in the Archean and the Proterozoic.
Collapse
Affiliation(s)
- Lily Momper
- Department of Earth, Atmospheric & Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Eileen Hu
- Department of Earth, Atmospheric & Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Kelsey R Moore
- Department of Earth, Atmospheric & Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Emilie J Skoog
- Department of Earth, Atmospheric & Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
| | - Madeline Tyler
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, USA
| | - Alexander J Evans
- Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI, USA
| | - Tanja Bosak
- Department of Earth, Atmospheric & Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| |
Collapse
|
20
|
Microbial diversity in a coastal environment with co-existing upwelling and mud-banks along the south west coast of India. Mol Biol Rep 2019; 46:3113-3127. [DOI: 10.1007/s11033-019-04766-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 03/14/2019] [Indexed: 10/27/2022]
|
21
|
Methods for extracting 'omes from microbialites. J Microbiol Methods 2019; 160:1-10. [PMID: 30877015 DOI: 10.1016/j.mimet.2019.02.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Revised: 02/21/2019] [Accepted: 02/21/2019] [Indexed: 11/20/2022]
Abstract
Microbialites are organo-sedimentary structures formed by complex microbial communities that interact with abiotic factors to form carbonate rich fabrics. Extraction of DNA or total RNA from microbialites can be difficult because of the high carbonate mineral concentration and exopolymeric substances. The methods employed until now include substances such as cetyltrimethylammonium bromide, sodium dodecyl sulfate, xanthogenate, lysozyme and proteinase K, as well as mechanical disruption. Additionally, several commercial kits have been used to improve DNA and total RNA extraction. This minireview presents different methods applied for DNA and RNA extraction from microbialites and discusses their advantages and disadvantages. Moreover, extraction of all 'omes (DNA, RNA, Protein, Lipids, polar metabolites) using multiomic extraction methods (MPlex), as well as the state of art for extraction of viruses from microbialites, are also discussed.
Collapse
|
22
|
Functional shifts in microbial mats recapitulate early Earth metabolic transitions. Nat Ecol Evol 2018; 2:1700-1708. [PMID: 30297749 PMCID: PMC6217971 DOI: 10.1038/s41559-018-0683-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 08/31/2018] [Indexed: 11/09/2022]
Abstract
Phototrophic microbial mats dominated terrestrial ecosystems for billions of years, largely causing, through cyanobacterial oxygenic photosynthesis, but also undergoing, the Great Oxidation Event approximately 2.5 billion years ago. Taking a space-for-time approach based on the universality of core metabolic pathways expressed at ecosystem level, we studied gene content and co-occurrence networks in high-diversity metagenomes from spatially close microbial mats along a steep redox gradient. The observed functional shifts suggest that anoxygenic photosynthesis was present but not predominant under early Precambrian conditions, being accompanied by other autotrophic processes. Our data also suggest that, in contrast to general assumptions, anoxygenic photosynthesis largely expanded in parallel with the subsequent evolution of oxygenic photosynthesis and aerobic respiration. Finally, our observations might represent space-for-time evidence that the Wood-Ljungdahl carbon fixation pathway dominated phototrophic mats in early ecosystems, whereas the Calvin cycle probably evolved from pre-existing variants before becoming the dominant contemporary form of carbon fixation.
Collapse
|
23
|
Babilonia J, Conesa A, Casaburi G, Pereira C, Louyakis AS, Reid RP, Foster JS. Comparative Metagenomics Provides Insight Into the Ecosystem Functioning of the Shark Bay Stromatolites, Western Australia. Front Microbiol 2018; 9:1359. [PMID: 29988640 PMCID: PMC6027182 DOI: 10.3389/fmicb.2018.01359] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Accepted: 06/05/2018] [Indexed: 12/22/2022] Open
Abstract
Stromatolites are organosedimentary build-ups that have formed as a result of the sediment trapping, binding and precipitating activities of microbes. Today, extant systems provide an ideal platform for understanding the structure, composition, and interactions between stromatolite-forming microbial communities and their respective environments. In this study, we compared the metagenomes of three prevalent stromatolite-forming microbial mat types in the Spaven Province of Hamelin Pool, Shark Bay located in Western Australia. These stromatolite-forming mat types included an intertidal pustular mat as well as a smooth and colloform mat types located in the subtidal zone. Additionally, the metagenomes of an adjacent, non-lithifying mat located in the upper intertidal zone were also sequenced for comparative purposes. Taxonomic and functional gene analyses revealed distinctive differences between the lithifying and non-lithifying mat types, which strongly correlated with water depth. Three distinct populations emerged including the upper intertidal non-lithifying mats, the intertidal pustular mats associated with unlaminated carbonate build-ups, and the subtidal colloform and smooth mat types associated with laminated structures. Functional analysis of metagenomes revealed that amongst stromatolite-forming mats there was an enrichment of photosynthesis pathways in the pustular stromatolite-forming mats. In the colloform and smooth stromatolite-forming mats, however, there was an increase in the abundance of genes associated with those heterotrophic metabolisms typically associated with carbonate mineralization, such as sulfate reduction. The comparative metagenomic analyses suggest that stromatolites of Hamelin Pool may form by two distinctive processes that are highly dependent on water depth. These results provide key insight into the potential adaptive strategies and synergistic interactions between microbes and their environments that may lead to stromatolite formation and accretion.
Collapse
Affiliation(s)
- Joany Babilonia
- Space Life Science Lab, Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, United States
| | - Ana Conesa
- Department of Microbiology and Cell Science, Genetics Institute, Institute for Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States.,Genomics of Gene Expression Laboratory, Prince Felipe Research Center, Valencia, Spain
| | - Giorgio Casaburi
- Space Life Science Lab, Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, United States
| | - Cecile Pereira
- Department of Microbiology and Cell Science, Genetics Institute, Institute for Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States.,EURA NOVA, Marseille, France
| | - Artemis S Louyakis
- Space Life Science Lab, Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, United States
| | - R Pamela Reid
- Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, United States
| | - Jamie S Foster
- Space Life Science Lab, Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, United States
| |
Collapse
|
24
|
White Iii RA, Wong HL, Ruvindy R, Neilan BA, Burns BP. Viral Communities of Shark Bay Modern Stromatolites. Front Microbiol 2018; 9:1223. [PMID: 29951046 PMCID: PMC6008428 DOI: 10.3389/fmicb.2018.01223] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 05/22/2018] [Indexed: 01/21/2023] Open
Abstract
Single stranded DNA viruses have been previously shown to populate the oceans on a global scale, and are endemic in microbialites of both marine and freshwater systems. We undertook for the first time direct viral metagenomic shotgun sequencing to explore the diversity of viruses in the modern stromatolites of Shark Bay Australia. The data indicate that Shark Bay marine stromatolites have similar diversity of ssDNA viruses to that of Highbourne Cay, Bahamas. ssDNA viruses in cluster uniquely in Shark Bay and Highbourne Cay, potentially due to enrichment by phi29-mediated amplification bias. Further, pyrosequencing data was assembled from the Shark Bay systems into two putative viral genomes that are related to Genomoviridae family of ssDNA viruses. In addition, the cellular fraction was shown to be enriched for antiviral defense genes including CRISPR-Cas, BREX (bacteriophage exclusion), and DISARM (defense island system associated with restriction-modification), a potentially novel finding for these systems. This is the first evidence for viruses in the Shark Bay stromatolites, and these viruses may play key roles in modulating microbial diversity as well as potentially impacting ecosystem function through infection and the recycling of key nutrients.
Collapse
Affiliation(s)
- Richard Allen White Iii
- Institute of Biological Chemistry, Washington State University, Pullman, WA, United States.,Crop and Soil Sciences, Washington State University, Pullman, WA, United States.,Plant Pathology, Washington State University, Pullman, WA, United States.,Australian Centre for Astrobiology, University of New South Wales, Sydney, NSW, Australia.,RAW Molecular Systems (RMS) LLC, Spokane, WA, United States
| | - Hon L Wong
- Australian Centre for Astrobiology, University of New South Wales, Sydney, NSW, Australia.,School of Biotechnology and Biomolecular Science, University of New South Wales, Sydney, NSW, Australia
| | - Rendy Ruvindy
- Australian Centre for Astrobiology, University of New South Wales, Sydney, NSW, Australia.,School of Biotechnology and Biomolecular Science, University of New South Wales, Sydney, NSW, Australia
| | - Brett A Neilan
- Australian Centre for Astrobiology, University of New South Wales, Sydney, NSW, Australia.,School of Biotechnology and Biomolecular Science, University of New South Wales, Sydney, NSW, Australia
| | - Brendan P Burns
- Australian Centre for Astrobiology, University of New South Wales, Sydney, NSW, Australia.,School of Biotechnology and Biomolecular Science, University of New South Wales, Sydney, NSW, Australia
| |
Collapse
|
25
|
Living Dendrolitic Microbial Mats in Hamelin Pool, Shark Bay, Western Australia. GEOSCIENCES 2018. [DOI: 10.3390/geosciences8060212] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
26
|
Johnson DB, Beddows PA, Flynn TM, Osburn MR. Microbial diversity and biomarker analysis of modern freshwater microbialites from Laguna Bacalar, Mexico. GEOBIOLOGY 2018; 16:319-337. [PMID: 29656514 DOI: 10.1111/gbi.12283] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 02/12/2018] [Indexed: 06/08/2023]
Abstract
Laguna Bacalar is a sulfate-rich freshwater lake on the Yucatan Peninsula that hosts large microbialites. High sulfate concentrations distinguish Laguna Bacalar from other freshwater microbialite sites such as Pavilion Lake and Alchichica, Mexico, as well as from other aqueous features on the Yucatan Peninsula. While cyanobacterial populations have been described here previously, this study offers a more complete characterization of the microbial populations and corresponding biogeochemical cycling using a three-pronged geobiological approach of microscopy, high-throughput DNA sequencing, and lipid biomarker analyses. We identify and compare diverse microbial communities of Alphaproteobacteria, Deltaproteobacteria, and Gammaproteobacteria that vary with location along a bank-to-bank transect across the lake, within microbialites, and within a neighboring mangrove root agglomeration. In particular, sulfate-reducing bacteria are extremely common and diverse, constituting 7%-19% of phylogenetic diversity within the microbialites, and are hypothesized to significantly influence carbonate precipitation. In contrast, Cyanobacteria account for less than 1% of phylogenetic diversity. The distribution of lipid biomarkers reflects these changes in microbial ecology, providing meaningful biosignatures for the microbes in this system. Polysaturated short-chain fatty acids characteristic of cyanobacteria account for <3% of total abundance in Laguna Bacalar microbialites. By contrast, even short-chain and monounsaturated short-chain fatty acids attributable to both Cyanobacteria and many other organisms including types of Alphaproteobacteria and Gammaproteobacteria constitute 43%-69% and 17%-25%, respectively, of total abundance in microbialites. While cyanobacteria are the largest and most visible microbes within these microbialites and dominate the mangrove root agglomeration, it is clear that their smaller, metabolically diverse associates are responsible for significant biogeochemical cycling in this microbialite system.
Collapse
Affiliation(s)
- D B Johnson
- Department of Earth and Planetary Sciences, Northwestern University, Evanston, IL, USA
| | - P A Beddows
- Department of Earth and Planetary Sciences, Northwestern University, Evanston, IL, USA
| | - T M Flynn
- Biosciences Division, Argonne National Laboratory, Argonne, IL, USA
| | - M R Osburn
- Department of Earth and Planetary Sciences, Northwestern University, Evanston, IL, USA
| |
Collapse
|
27
|
Louyakis AS, Gourlé H, Casaburi G, Bonjawo RME, Duscher AA, Foster JS. A year in the life of a thrombolite: comparative metatranscriptomics reveals dynamic metabolic changes over diel and seasonal cycles. Environ Microbiol 2017; 20:842-861. [DOI: 10.1111/1462-2920.14029] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Revised: 12/12/2017] [Accepted: 12/12/2017] [Indexed: 12/01/2022]
Affiliation(s)
- Artemis S. Louyakis
- Department of Microbiology and Cell Science; University of Florida, Space Life Sciences Lab; Merritt Island FL USA
| | - Hadrien Gourlé
- Department of Microbiology and Cell Science; University of Florida, Space Life Sciences Lab; Merritt Island FL USA
- Department of Animal Breeding and Genetics; Global Bioinformatics Centre, Swedish University of Agricultural Sciences; Uppsala Sweden
| | - Giorgio Casaburi
- Department of Microbiology and Cell Science; University of Florida, Space Life Sciences Lab; Merritt Island FL USA
| | - Rachelle M. E. Bonjawo
- Department of Microbiology and Cell Science; University of Florida, Space Life Sciences Lab; Merritt Island FL USA
| | - Alexandrea A. Duscher
- Department of Microbiology and Cell Science; University of Florida, Space Life Sciences Lab; Merritt Island FL USA
| | - Jamie S. Foster
- Department of Microbiology and Cell Science; University of Florida, Space Life Sciences Lab; Merritt Island FL USA
| |
Collapse
|
28
|
Shapiro JA. Living Organisms Author Their Read-Write Genomes in Evolution. BIOLOGY 2017; 6:E42. [PMID: 29211049 PMCID: PMC5745447 DOI: 10.3390/biology6040042] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 11/17/2017] [Accepted: 11/28/2017] [Indexed: 12/18/2022]
Abstract
Evolutionary variations generating phenotypic adaptations and novel taxa resulted from complex cellular activities altering genome content and expression: (i) Symbiogenetic cell mergers producing the mitochondrion-bearing ancestor of eukaryotes and chloroplast-bearing ancestors of photosynthetic eukaryotes; (ii) interspecific hybridizations and genome doublings generating new species and adaptive radiations of higher plants and animals; and, (iii) interspecific horizontal DNA transfer encoding virtually all of the cellular functions between organisms and their viruses in all domains of life. Consequently, assuming that evolutionary processes occur in isolated genomes of individual species has become an unrealistic abstraction. Adaptive variations also involved natural genetic engineering of mobile DNA elements to rewire regulatory networks. In the most highly evolved organisms, biological complexity scales with "non-coding" DNA content more closely than with protein-coding capacity. Coincidentally, we have learned how so-called "non-coding" RNAs that are rich in repetitive mobile DNA sequences are key regulators of complex phenotypes. Both biotic and abiotic ecological challenges serve as triggers for episodes of elevated genome change. The intersections of cell activities, biosphere interactions, horizontal DNA transfers, and non-random Read-Write genome modifications by natural genetic engineering provide a rich molecular and biological foundation for understanding how ecological disruptions can stimulate productive, often abrupt, evolutionary transformations.
Collapse
Affiliation(s)
- James A Shapiro
- Department of Biochemistry and Molecular Biology, University of Chicago GCIS W123B, 979 E. 57th Street, Chicago, IL 60637, USA.
| |
Collapse
|
29
|
Proemse BC, Eberhard RS, Sharples C, Bowman JP, Richards K, Comfort M, Barmuta LA. Stromatolites on the rise in peat-bound karstic wetlands. Sci Rep 2017; 7:15384. [PMID: 29133809 PMCID: PMC5684344 DOI: 10.1038/s41598-017-15507-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 10/27/2017] [Indexed: 02/01/2023] Open
Abstract
Stromatolites are the oldest evidence for life on Earth, but modern living examples are rare and predominantly occur in shallow marine or (hyper-) saline lacustrine environments, subject to exotic physico-chemical conditions. Here we report the discovery of living freshwater stromatolites in cool-temperate karstic wetlands in the Giblin River catchment of the UNESCO-listed Tasmanian Wilderness World Heritage Area, Australia. These stromatolites colonize the slopes of karstic spring mounds which create mildly alkaline (pH of 7.0-7.9) enclaves within an otherwise uniformly acidic organosol terrain. The freshwater emerging from the springs is Ca-HCO3 dominated and water temperatures show no evidence of geothermal heating. Using 16 S rRNA gene clone library analysis we revealed that the bacterial community is dominated by Cyanobacteria, Alphaproteobacteria and an unusually high proportion of Chloroflexi, followed by Armatimonadetes and Planctomycetes, and is therefore unique compared to other living examples. Macroinvertebrates are sparse and snails in particular are disadvantaged by the development of debilitating accumulations of carbonate on their shells, corroborating evidence that stromatolites flourish under conditions where predation by metazoans is suppressed. Our findings constitute a novel habitat for stromatolites because cool-temperate freshwater wetlands are not a conventional stromatolite niche, suggesting that stromatolites may be more common than previously thought.
Collapse
Affiliation(s)
- Bernadette C Proemse
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania, 7001, Australia
- Australian Centre for Research on Separation Science, University of Tasmania, Tasmania, 7001, Australia
| | - Rolan S Eberhard
- Department of Primary Industries, Parks, Water & Environment, GPO Box 44, Hobart, Tasmania, 7001, Australia.
| | - Chris Sharples
- Geography and Spatial Science, University of Tasmania, Private Bag 76, Hobart, Tasmania, 7001, Australia
| | - John P Bowman
- Tasmanian Institute of Agriculture, University of Tasmania, Private Bag 98, Hobart, Tasmania, 7001, Australia
| | - Karen Richards
- Department of Primary Industries, Parks, Water & Environment, GPO Box 44, Hobart, Tasmania, 7001, Australia
| | - Michael Comfort
- Department of Primary Industries, Parks, Water & Environment, GPO Box 44, Hobart, Tasmania, 7001, Australia
| | - Leon A Barmuta
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania, 7001, Australia
| |
Collapse
|
30
|
Koo H, Mojib N, Hakim JA, Hawes I, Tanabe Y, Andersen DT, Bej AK. Microbial Communities and Their Predicted Metabolic Functions in Growth Laminae of a Unique Large Conical Mat from Lake Untersee, East Antarctica. Front Microbiol 2017; 8:1347. [PMID: 28824553 PMCID: PMC5543034 DOI: 10.3389/fmicb.2017.01347] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 07/03/2017] [Indexed: 01/15/2023] Open
Abstract
In this study, we report the distribution of microbial taxa and their predicted metabolic functions observed in the top (U1), middle (U2), and inner (U3) decadal growth laminae of a unique large conical microbial mat from perennially ice-covered Lake Untersee of East Antarctica, using NextGen sequencing of the 16S rRNA gene and bioinformatics tools. The results showed that the U1 lamina was dominated by cyanobacteria, specifically Phormidium sp., Leptolyngbya sp., and Pseudanabaena sp. The U2 and U3 laminae had high abundances of Actinobacteria, Verrucomicrobia, Proteobacteria, and Bacteroidetes. Closely related taxa within each abundant bacterial taxon found in each lamina were further differentiated at the highest taxonomic resolution using the oligotyping method. PICRUSt analysis, which determines predicted KEGG functional categories from the gene contents and abundances among microbial communities, revealed a high number of sequences belonging to carbon fixation, energy metabolism, cyanophycin, chlorophyll, and photosynthesis proteins in the U1 lamina. The functional predictions of the microbial communities in U2 and U3 represented signal transduction, membrane transport, zinc transport and amino acid-, carbohydrate-, and arsenic- metabolisms. The Nearest Sequenced Taxon Index (NSTI) values processed through PICRUSt were 0.10, 0.13, and 0.11 for U1, U2, and U3 laminae, respectively. These values indicated a close correspondence with the reference microbial genome database, implying high confidence in the predicted metabolic functions of the microbial communities in each lamina. The distribution of microbial taxa observed in each lamina and their predicted metabolic functions provides additional insight into the complex microbial ecosystem at Lake Untersee, and lays the foundation for studies that will enhance our understanding of the mechanisms responsible for the formation of these unique mat structures and their evolutionary significance.
Collapse
Affiliation(s)
- Hyunmin Koo
- Department of Biology, University of Alabama at Birmingham, BirminghamAL, United States
| | - Nazia Mojib
- Department of Biology, University of Alabama at Birmingham, BirminghamAL, United States
| | - Joseph A Hakim
- Department of Biology, University of Alabama at Birmingham, BirminghamAL, United States
| | - Ian Hawes
- Gateway Antarctica, University of CanterburyChristchurch, New Zealand
| | - Yukiko Tanabe
- National Institute of Polar ResearchTachikawa, Japan
| | - Dale T Andersen
- Carl Sagan Center, SETI Institute, Mountain ViewCA, United States
| | - Asim K Bej
- Department of Biology, University of Alabama at Birmingham, BirminghamAL, United States
| |
Collapse
|
31
|
Ramos VMC, Castelo-Branco R, Leão PN, Martins J, Carvalhal-Gomes S, Sobrinho da Silva F, Mendonça Filho JG, Vasconcelos VM. Cyanobacterial Diversity in Microbial Mats from the Hypersaline Lagoon System of Araruama, Brazil: An In-depth Polyphasic Study. Front Microbiol 2017; 8:1233. [PMID: 28713360 PMCID: PMC5492833 DOI: 10.3389/fmicb.2017.01233] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 06/19/2017] [Indexed: 11/24/2022] Open
Abstract
Microbial mats are complex, micro-scale ecosystems that can be found in a wide range of environments. In the top layer of photosynthetic mats from hypersaline environments, a large diversity of cyanobacteria typically predominates. With the aim of strengthening the knowledge on the cyanobacterial diversity present in the coastal lagoon system of Araruama (state of Rio de Janeiro, Brazil), we have characterized three mat samples by means of a polyphasic approach. We have used morphological and molecular data obtained by culture-dependent and -independent methods. Moreover, we have compared different classification methodologies and discussed the outcomes, challenges, and pitfalls of these methods. Overall, we show that Araruama's lagoons harbor a high cyanobacterial diversity. Thirty-six unique morphospecies could be differentiated, which increases by more than 15% the number of morphospecies and genera already reported for the entire Araruama system. Morphology-based data were compared with the 16S rRNA gene phylogeny derived from isolate sequences and environmental sequences obtained by PCR-DGGE and pyrosequencing. Most of the 48 phylotypes could be associated with the observed morphospecies at the order level. More than one third of the sequences demonstrated to be closely affiliated (best BLAST hit results of ≥99%) with cyanobacteria from ecologically similar habitats. Some sequences had no close relatives in the public databases, including one from an isolate, being placed as “loner” sequences within different orders. This hints at hidden cyanobacterial diversity in the mats of the Araruama system, while reinforcing the relevance of using complementary approaches to study cyanobacterial diversity.
Collapse
Affiliation(s)
- Vitor M C Ramos
- Faculty of Sciences, University of PortoPorto, Portugal.,Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of PortoMatosinhos, Portugal
| | - Raquel Castelo-Branco
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of PortoMatosinhos, Portugal
| | - Pedro N Leão
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of PortoMatosinhos, Portugal
| | - Joana Martins
- Faculty of Sciences, University of PortoPorto, Portugal.,Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of PortoMatosinhos, Portugal
| | - Sinda Carvalhal-Gomes
- Palynofacies and Organic Facies Laboratory, Department of Geology, Federal University of Rio de JaneiroRio de Janeiro, Brazil
| | - Frederico Sobrinho da Silva
- Palynofacies and Organic Facies Laboratory, Department of Geology, Federal University of Rio de JaneiroRio de Janeiro, Brazil
| | - João G Mendonça Filho
- Palynofacies and Organic Facies Laboratory, Department of Geology, Federal University of Rio de JaneiroRio de Janeiro, Brazil
| | - Vitor M Vasconcelos
- Faculty of Sciences, University of PortoPorto, Portugal.,Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of PortoMatosinhos, Portugal
| |
Collapse
|
32
|
Decho AW, Gutierrez T. Microbial Extracellular Polymeric Substances (EPSs) in Ocean Systems. Front Microbiol 2017; 8:922. [PMID: 28603518 PMCID: PMC5445292 DOI: 10.3389/fmicb.2017.00922] [Citation(s) in RCA: 256] [Impact Index Per Article: 36.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 05/08/2017] [Indexed: 12/13/2022] Open
Abstract
Microbial cells (i.e., bacteria, archaea, microeukaryotes) in oceans secrete a diverse array of large molecules, collectively called extracellular polymeric substances (EPSs) or simply exopolymers. These secretions facilitate attachment to surfaces that lead to the formation of structured 'biofilm' communities. In open-water environments, they also lead to formation of organic colloids, and larger aggregations of cells, called 'marine snow.' Secretion of EPS is now recognized as a fundamental microbial adaptation, occurring under many environmental conditions, and one that influences many ocean processes. This relatively recent realization has revolutionized our understanding of microbial impacts on ocean systems. EPS occur in a range of molecular sizes, conformations and physical/chemical properties, and polysaccharides, proteins, lipids, and even nucleic acids are actively secreted components. Interestingly, however, the physical ultrastructure of how individual EPS interact with each other is poorly understood. Together, the EPS matrix molecules form a three-dimensional architecture from which cells may localize extracellular activities and conduct cooperative/antagonistic interactions that cannot be accomplished efficiently by free-living cells. EPS alter optical signatures of sediments and seawater, and are involved in biogeomineral precipitation and the construction of microbial macrostructures, and horizontal-transfers of genetic information. In the water-column, they contribute to the formation of marine snow, transparent exopolymer particles (TEPs), sea-surface microlayer biofilm, and marine oil snow. Excessive production of EPS occurs during later-stages of phytoplankton blooms as an excess metabolic by product and releases a carbon pool that transitions among dissolved-, colloidal-, and gel-states. Some EPS are highly labile carbon forms, while other forms appear quite refractory to degradation. Emerging studies suggest that EPS contribute to efficient trophic-transfer of environmental contaminants, and may provide a protective refugia for pathogenic cells within marine systems; one that enhances their survival/persistence. Finally, these secretions are prominent in 'extreme' environments ranging from sea-ice communities to hypersaline systems to the high-temperatures/pressures of hydrothermal-vent systems. This overview summarizes some of the roles of exopolymer in oceans.
Collapse
Affiliation(s)
- Alan W. Decho
- Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, ColumbiaSC, United States
| | - Tony Gutierrez
- School of Engineering and Physical Sciences, Heriot-Watt UniversityEdinburgh, United Kingdom
| |
Collapse
|
33
|
Kurth D, Amadio A, Ordoñez OF, Albarracín VH, Gärtner W, Farías ME. Arsenic metabolism in high altitude modern stromatolites revealed by metagenomic analysis. Sci Rep 2017; 7:1024. [PMID: 28432307 PMCID: PMC5430908 DOI: 10.1038/s41598-017-00896-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 03/16/2017] [Indexed: 11/09/2022] Open
Abstract
Modern stromatolites thrive only in selected locations in the world. Socompa Lake, located in the Andean plateau at 3570 masl, is one of the numerous extreme Andean microbial ecosystems described over recent years. Extreme environmental conditions include hypersalinity, high UV incidence, and high arsenic content, among others. After Socompa's stromatolite microbial communities were analysed by metagenomic DNA sequencing, taxonomic classification showed dominance of Proteobacteria, Bacteroidetes and Firmicutes, and a remarkably high number of unclassified sequences. A functional analysis indicated that carbon fixation might occur not only by the Calvin-Benson cycle, but also through alternative pathways such as the reverse TCA cycle, and the reductive acetyl-CoA pathway. Deltaproteobacteria were involved both in sulfate reduction and nitrogen fixation. Significant differences were found when comparing the Socompa stromatolite metagenome to the Shark Bay (Australia) smooth mat metagenome: namely, those involving stress related processes, particularly, arsenic resistance. An in-depth analysis revealed a surprisingly diverse metabolism comprising all known types of As resistance and energy generating pathways. While the ars operon was the main mechanism, an important abundance of arsM genes was observed in selected phyla. The data resulting from this work will prove a cornerstone for further studies on this rare microbial community.
Collapse
Affiliation(s)
- Daniel Kurth
- Planta Piloto de Procesos Industriales y Microbiológicos (PROIMI), CCT Tucumán, CONICET, San Miguel de Tucumán, Argentina
| | - Ariel Amadio
- E.E.A. Rafaela, Instituto Nacional de Tecnología Agropecuaria (INTA), CCT Santa Fe, CONICET, Rafaela, Argentina
| | - Omar F Ordoñez
- Planta Piloto de Procesos Industriales y Microbiológicos (PROIMI), CCT Tucumán, CONICET, San Miguel de Tucumán, Argentina
| | - Virginia H Albarracín
- Planta Piloto de Procesos Industriales y Microbiológicos (PROIMI), CCT Tucumán, CONICET, San Miguel de Tucumán, Argentina
- Facultad de Ciencias Naturales e Instituto Miguel Lillo, Universidad Nacional de Tucumán, San Miguel de Tucumán, Argentina
| | - Wolfgang Gärtner
- Max-Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr, Germany
| | - María E Farías
- Planta Piloto de Procesos Industriales y Microbiológicos (PROIMI), CCT Tucumán, CONICET, San Miguel de Tucumán, Argentina.
| |
Collapse
|
34
|
Toneatti DM, Albarracín VH, Flores MR, Polerecky L, Farías ME. Stratified Bacterial Diversity along Physico-chemical Gradients in High-Altitude Modern Stromatolites. Front Microbiol 2017; 8:646. [PMID: 28446906 PMCID: PMC5388776 DOI: 10.3389/fmicb.2017.00646] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 03/29/2017] [Indexed: 11/13/2022] Open
Abstract
At an altitude of 3,570 m, the volcanic lake Socompa in the Argentinean Andes is presently the highest site where actively forming stromatolite-like structures have been reported. Interestingly, pigment and microsensor analyses performed through the different layers of the stromatolites (50 mm-deep) showed steep vertical gradients of light and oxygen, hydrogen sulfide and pH in the porewater. Given the relatively good characterization of these physico-chemical gradients, the aim of this follow-up work was to specifically address how the bacterial diversity stratified along the top six layers of the stromatolites which seems the most metabolically important and diversified zone of the whole microbial community. We herein discussed how, in only 7 mm, a drastic succession of metabolic adaptations occurred: i.e., microbial communities shift from a UV-high/oxic world to an IR-low/anoxic/high H2S environment which force stratification and metabolic specialization of the bacterial community, thus, modulating the chemical faces of the Socompa stromatolites. The oxic zone was dominated by Deinococcus sp. at top surface (0.3 mm), followed by a second layer of Coleofasciculus sp. (0.3 to ∼2 mm). Sequences from anoxygenic phototrophic Alphaproteobacteria, along with an increasing diversity of phyla including Bacteroidetes, Spirochaetes were found at middle layers 3 and 4. Deeper layers (5–7 mm) were mostly occupied by sulfate reducers of Deltaproteobacteria, Bacteroidetes and Firmicutes, next to a high diversity and equitable community of rare, unclassified and candidate phyla. This analysis showed how microbial communities stratified in a physicochemical vertical profile and according to the light source. It also gives an insight of which bacterial metabolic capabilities might operate and produce a microbial cooperative strategy to thrive in one of the most extreme environments on Earth.
Collapse
Affiliation(s)
- Diego M Toneatti
- Planta Piloto de Procesos Industriales y Microbiológicos, Centro Científico Tecnológico - Consejo Nacional de Investigaciones Científicas y TécnicasSan Miguel de Tucumán, Argentina
| | - Virginia H Albarracín
- Planta Piloto de Procesos Industriales y Microbiológicos, Centro Científico Tecnológico - Consejo Nacional de Investigaciones Científicas y TécnicasSan Miguel de Tucumán, Argentina.,Facultad de Ciencias Naturales e Instituto Miguel Lillo, Universidad Nacional de TucumánSan Miguel de Tucumán, Argentina.,Centro Integral de Microscopía Electrónica, Centro Científico Tecnológico - Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de TucumánSan Miguel de Tucumán, Argentina
| | - Maria R Flores
- Department of Earth Sciences - Geochemistry, Utrecht UniversityUtrecht, Netherlands
| | - Lubos Polerecky
- Department of Earth Sciences - Geochemistry, Utrecht UniversityUtrecht, Netherlands
| | - María E Farías
- Planta Piloto de Procesos Industriales y Microbiológicos, Centro Científico Tecnológico - Consejo Nacional de Investigaciones Científicas y TécnicasSan Miguel de Tucumán, Argentina
| |
Collapse
|
35
|
Wong HL, Visscher PT, White RA, Smith DL, Patterson MM, Burns BP. Dynamics of archaea at fine spatial scales in Shark Bay mat microbiomes. Sci Rep 2017; 7:46160. [PMID: 28397816 PMCID: PMC5387419 DOI: 10.1038/srep46160] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 03/09/2017] [Indexed: 01/07/2023] Open
Abstract
The role of archaea in microbial mats is poorly understood. Delineating the spatial distribution of archaea with mat depth will enable resolution of putative niches in these systems. In the present study, high throughput amplicon sequencing was undertaken in conjunction with analysis of key biogeochemical properties of two mats (smooth and pustular) from Shark Bay, Australia. One-way analysis of similarity tests indicated the archaeal community structures of smooth and pustular mats were significantly different (global R = 1, p = 0.1%). Smooth mats possessed higher archaeal diversity, dominated by Parvarchaeota. The methanogenic community in smooth mats was dominated by hydrogenotrophic Methanomicrobiales, as well as methylotrophic Methanosarcinales, Methanococcales, Methanobacteriales and Methanomassiliicoccaceae. Pustular mats were enriched with Halobacteria and Parvarchaeota. Key metabolisms (bacterial and archaeal) were measured, and the rates of oxygen production/consumption and sulfate reduction were up to four times higher in smooth than in pustular mats. Methane production peaked in the oxic layers and was up to seven-fold higher in smooth than pustular mats. The finding of an abundance of anaerobic methanogens enriched at the surface where oxygen levels were highest, coupled with peak methane production in the oxic zone, suggests putative surface anoxic niches in these microbial mats.
Collapse
Affiliation(s)
- Hon Lun Wong
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia.,Australian Centre for Astrobiology, University of New South Wales Sydney, Australia
| | - Pieter T Visscher
- Department of Marine Sciences, University of Connecticut, USA.,Australian Centre for Astrobiology, University of New South Wales Sydney, Australia
| | - Richard Allen White
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - Daniela-Lee Smith
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia
| | | | - Brendan P Burns
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia.,Australian Centre for Astrobiology, University of New South Wales Sydney, Australia
| |
Collapse
|
36
|
Fernandez AB, Rasuk MC, Visscher PT, Contreras M, Novoa F, Poire DG, Patterson MM, Ventosa A, Farias ME. Microbial Diversity in Sediment Ecosystems (Evaporites Domes, Microbial Mats, and Crusts) of Hypersaline Laguna Tebenquiche, Salar de Atacama, Chile. Front Microbiol 2016; 7:1284. [PMID: 27597845 PMCID: PMC4992683 DOI: 10.3389/fmicb.2016.01284] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 08/04/2016] [Indexed: 02/01/2023] Open
Abstract
We combined nucleic acid-based molecular methods, biogeochemical measurements, and physicochemical characteristics to investigate microbial sedimentary ecosystems of Laguna Tebenquiche, Atacama Desert, Chile. Molecular diversity, and biogeochemistry of hypersaline microbial mats, rhizome-associated concretions, and an endoevaporite were compared with: The V4 hypervariable region of the 16S rRNA gene was amplified by pyrosequencing to analyze the total microbial diversity (i.e., bacteria and archaea) in bulk samples, and in addition, in detail on a millimeter scale in one microbial mat and in one evaporite. Archaea were more abundant than bacteria. Euryarchaeota was one of the most abundant phyla in all samples, and particularly dominant (97% of total diversity) in the most lithified ecosystem, the evaporite. Most of the euryarchaeal OTUs could be assigned to the class Halobacteria or anaerobic and methanogenic archaea. Planctomycetes potentially also play a key role in mats and rhizome-associated concretions, notably the aerobic organoheterotroph members of the class Phycisphaerae. In addition to cyanobacteria, members of Chromatiales and possibly the candidate family Chlorotrichaceae contributed to photosynthetic carbon fixation. Other abundant uncultured taxa such as the candidate division MSBL1, the uncultured MBGB, and the phylum Acetothermia potentially play an important metabolic role in these ecosystems. Lithifying microbial mats contained calcium carbonate precipitates, whereas endoevoporites consisted of gypsum, and halite. Biogeochemical measurements revealed that based on depth profiles of O2 and sulfide, metabolic activities were much higher in the non-lithifying mat (peaking in the least lithified systems) than in lithifying mats with the lowest activity in endoevaporites. This trend in decreasing microbial activity reflects the increase in salinity, which may play an important role in the biodiversity.
Collapse
Affiliation(s)
- Ana B Fernandez
- Laboratorio de Investigaciones Microbiológicas de Lagunas Andinas, Planta Piloto de Procesos Industriales Microbiológicos, Centro Científico Tecnológico, CONICET Tucumán, Argentina
| | - Maria C Rasuk
- Laboratorio de Investigaciones Microbiológicas de Lagunas Andinas, Planta Piloto de Procesos Industriales Microbiológicos, Centro Científico Tecnológico, CONICET Tucumán, Argentina
| | - Pieter T Visscher
- Department of Marine Sciences, University of ConnecticutGroton, CT, USA; Australian Centre for Astrobiology, University of New South WalesSydney, NSW, Australia
| | | | | | - Daniel G Poire
- Centro de Investigaciones Geológicas, Universidad Nacional de La Plata-Conicet La Plata, Argentina
| | - Molly M Patterson
- Department of Marine Sciences, University of Connecticut Groton, CT, USA
| | - Antonio Ventosa
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla Sevilla, Spain
| | - Maria E Farias
- Laboratorio de Investigaciones Microbiológicas de Lagunas Andinas, Planta Piloto de Procesos Industriales Microbiológicos, Centro Científico Tecnológico, CONICET Tucumán, Argentina
| |
Collapse
|
37
|
White RA, Chan AM, Gavelis GS, Leander BS, Brady AL, Slater GF, Lim DSS, Suttle CA. Metagenomic Analysis Suggests Modern Freshwater Microbialites Harbor a Distinct Core Microbial Community. Front Microbiol 2016; 6:1531. [PMID: 26903951 PMCID: PMC4729913 DOI: 10.3389/fmicb.2015.01531] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 12/21/2015] [Indexed: 11/13/2022] Open
Abstract
Modern microbialites are complex microbial communities that interface with abiotic factors to form carbonate-rich organosedimentary structures whose ancestors provide the earliest evidence of life. Past studies primarily on marine microbialites have inventoried diverse taxa and metabolic pathways, but it is unclear which of these are members of the microbialite community and which are introduced from adjacent environments. Here we control for these factors by sampling the surrounding water and nearby sediment, in addition to the microbialites and use a metagenomics approach to interrogate the microbial community. Our findings suggest that the Pavilion Lake microbialite community profile, metabolic potential and pathway distributions are distinct from those in the neighboring sediments and water. Based on RefSeq classification, members of the Proteobacteria (e.g., alpha and delta classes) were the dominant taxa in the microbialites, and possessed novel functional guilds associated with the metabolism of heavy metals, antibiotic resistance, primary alcohol biosynthesis and urea metabolism; the latter may help drive biomineralization. Urea metabolism within Pavilion Lake microbialites is a feature not previously associated in other microbialites. The microbialite communities were also significantly enriched for cyanobacteria and acidobacteria, which likely play an important role in biomineralization. Additional findings suggest that Pavilion Lake microbialites are under viral selection as genes associated with viral infection (e.g CRISPR-Cas, phage shock and phage excision) are abundant within the microbialite metagenomes. The morphology of Pavilion Lake microbialites changes dramatically with depth; yet, metagenomic data did not vary significantly by morphology or depth, indicating that microbialite morphology is altered by other factors, perhaps transcriptional differences or abiotic conditions. This work provides a comprehensive metagenomic perspective of the interactions and differences between microbialites and their surrounding environment, and reveals the distinct nature of these complex communities.
Collapse
Affiliation(s)
- Richard Allen White
- Department of Microbiology and Immunology, University of British Columbia, Vancouver BC, Canada
| | - Amy M Chan
- Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver BC, Canada
| | - Gregory S Gavelis
- Department of Zoology, University of British Columbia, Vancouver BC, Canada
| | - Brian S Leander
- Department of Zoology, University of British Columbia, VancouverBC, Canada; Department of Botany, University of British Columbia, VancouverBC, Canada
| | - Allyson L Brady
- School of Geography and Earth Sciences, McMaster University, Hamilton ON, Canada
| | - Gregory F Slater
- School of Geography and Earth Sciences, McMaster University, Hamilton ON, Canada
| | - Darlene S S Lim
- Bay Area Environmental Institute, PetalumaCA, USA; NASA Ames Research Center, Moffett FieldCA, USA
| | - Curtis A Suttle
- Department of Microbiology and Immunology, University of British Columbia, VancouverBC, Canada; Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, VancouverBC, Canada; Department of Botany, University of British Columbia, VancouverBC, Canada; Canadian Institute for Advanced Research, TorontoON, Canada
| |
Collapse
|
38
|
Wong HL, Ahmed-Cox A, Burns BP. Molecular Ecology of Hypersaline Microbial Mats: Current Insights and New Directions. Microorganisms 2016; 4:microorganisms4010006. [PMID: 27681900 PMCID: PMC5029511 DOI: 10.3390/microorganisms4010006] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 12/08/2015] [Accepted: 12/15/2015] [Indexed: 11/17/2022] Open
Abstract
Microbial mats are unique geobiological ecosystems that form as a result of complex communities of microorganisms interacting with each other and their physical environment. Both the microorganisms present and the network of metabolic interactions govern ecosystem function therein. These systems are often found in a range of extreme environments, and those found in elevated salinity have been particularly well studied. The purpose of this review is to briefly describe the molecular ecology of select model hypersaline mat systems (Guerrero Negro, Shark Bay, S’Avall, and Kiritimati Atoll), and any potentially modulating effects caused by salinity to community structure. In addition, we discuss several emerging issues in the field (linking function to newly discovered phyla and microbial dark matter), which illustrate the changing paradigm that is seen as technology has rapidly advanced in the study of these extreme and evolutionally significant ecosystems.
Collapse
Affiliation(s)
- Hon Lun Wong
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney 2052, Australia.
- Australian Centre for Astrobiology, University of New South Wales, Sydney 2052, Australia.
| | - Aria Ahmed-Cox
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney 2052, Australia.
| | - Brendan Paul Burns
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney 2052, Australia.
- Australian Centre for Astrobiology, University of New South Wales, Sydney 2052, Australia.
| |
Collapse
|
39
|
Papineau D, De Gregorio B, Fearn S, Kilcoyne D, McMahon G, Purohit R, Fogel M. Nanoscale petrographic and geochemical insights on the origin of the Palaeoproterozoic stromatolitic phosphorites from Aravalli Supergroup, India. GEOBIOLOGY 2016; 14:3-32. [PMID: 26490161 DOI: 10.1111/gbi.12164] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 09/02/2015] [Indexed: 06/05/2023]
Abstract
Stromatolites composed of apatite occur in post-Lomagundi-Jatuli successions (late Palaeoproterozoic) and suggest the emergence of novel types of biomineralization at that time. The microscopic and nanoscopic petrology of organic matter in stromatolitic phosphorites might provide insights into the suite of diagenetic processes that formed these types of stromatolites. Correlated geochemical micro-analyses of the organic matter could also yield molecular, elemental and isotopic compositions and thus insights into the role of specific micro-organisms among these communities. Here, we report on the occurrence of nanoscopic disseminated organic matter in the Palaeoproterozoic stromatolitic phosphorite from the Aravalli Supergroup of north-west India. Organic petrography by micro-Raman and Transmission Electron Microscopy demonstrates syngeneity of the organic matter. Total organic carbon contents of these stromatolitic phosphorite columns are between 0.05 and 3.0 wt% and have a large range of δ(13) Corg values with an average of -18.5‰ (1σ = 4.5‰). δ(15) N values of decarbonated rock powders are between -1.2 and +2.7‰. These isotopic compositions point to the important role of biological N2 -fixation and CO2 -fixation by the pentose phosphate pathway consistent with a population of cyanobacteria. Microscopic spheroidal grains of apatite (MSGA) occur in association with calcite microspar in microbial mats from stromatolite columns and with chert in the core of diagenetic apatite rosettes. Organic matter extracted from the stromatolitic phosphorites contains a range of molecular functional group (e.g. carboxylic acid, alcohol, and aliphatic hydrocarbons) as well as nitrile and nitro groups as determined from C- and N-XANES spectra. The presence of organic nitrogen was independently confirmed by a CN(-) peak detected by ToF-SIMS. Nanoscale petrography and geochemistry allow for a refinement of the formation model for the accretion and phototrophic growth of stromatolites. The original microbial biomass is inferred to have been dominated by cyanobacteria, which might be an important contributor of organic matter in shallow-marine phosphorites.
Collapse
Affiliation(s)
- D Papineau
- London Centre for Nanotechnology, University College London, London, UK
- Department of Earth Sciences, University College London, London, UK
| | - B De Gregorio
- Material Science and Technology Division, Naval Research Laboratory, Washington, DC, USA
| | - S Fearn
- Department of Material Sciences, Imperial College, London, UK
| | - D Kilcoyne
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - G McMahon
- School of Materials, The University of Manchester, Manchester, UK
| | - R Purohit
- Department of Geology, Government College Sirohi, Sirohi, Rajasthan, India
| | - M Fogel
- University of California at Merced, Merced, CA, USA
| |
Collapse
|
40
|
Casaburi G, Duscher AA, Reid RP, Foster JS. Characterization of the stromatolite microbiome from Little Darby Island, The Bahamas using predictive and whole shotgun metagenomic analysis. Environ Microbiol 2015; 18:1452-69. [PMID: 26471001 DOI: 10.1111/1462-2920.13094] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Revised: 10/13/2015] [Accepted: 10/13/2015] [Indexed: 02/01/2023]
Abstract
Modern stromatolites represent ideal ecosystems to understand the biological processes required for the precipitation of carbonate due to their long evolutionary history and occurrence in a wide range of habitats. However, most of the prior molecular work on stromatolites has focused on understanding the taxonomic complexity and not fully elucidating the functional capabilities of these systems. Here, we begin to characterize the microbiome associated with stromatolites of Little Darby Island, The Bahamas using predictive metagenomics of the 16S rRNA gene coupled with direct whole shotgun sequencing. The metagenomic analysis of the Little Darby stromatolites revealed many shared taxa and core pathways associated with biologically induced carbonate precipitation, suggesting functional convergence within Bahamian stromatolites. A comparison of the Little Darby stromatolites with other lithifying microbial ecosystems also revealed that although factors, such as geographic location and salinity, do drive some differences within the population, there are extensive similarities within the microbial populations. These results suggest that for stromatolite formation, 'who' is in the community is not as critical as metabolic activities and environmental interactions. Together, these analyses help improve our understanding of the similarities among lithifying ecosystems and provide an important first step in characterizing the shared microbiome of modern stromatolites.
Collapse
Affiliation(s)
- Giorgio Casaburi
- Department of Microbiology and Cell Science, University of Florida, Space Life Science Lab, Merritt Island, FL, USA
| | - Alexandrea A Duscher
- Department of Microbiology and Cell Science, University of Florida, Space Life Science Lab, Merritt Island, FL, USA
| | - R Pamela Reid
- Rosenstiel School of Marine Sciences, University of Miami, Miami, FL, USA
| | - Jamie S Foster
- Department of Microbiology and Cell Science, University of Florida, Space Life Science Lab, Merritt Island, FL, USA
| |
Collapse
|
41
|
Wong HL, Smith DL, Visscher PT, Burns BP. Niche differentiation of bacterial communities at a millimeter scale in Shark Bay microbial mats. Sci Rep 2015; 5:15607. [PMID: 26499760 PMCID: PMC4620479 DOI: 10.1038/srep15607] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 09/28/2015] [Indexed: 02/01/2023] Open
Abstract
Modern microbial mats can provide key insights into early Earth ecosystems, and Shark Bay, Australia, holds one of the best examples of these systems. Identifying the spatial distribution of microorganisms with mat depth facilitates a greater understanding of specific niches and potentially novel microbial interactions. High throughput sequencing coupled with elemental analyses and biogeochemical measurements of two distinct mat types (smooth and pustular) at a millimeter scale were undertaken in the present study. A total of 8,263,982 16S rRNA gene sequences were obtained, which were affiliated to 58 bacterial and candidate phyla. The surface of both mats were dominated by Cyanobacteria, accompanied with known or putative members of Alphaproteobacteria and Bacteroidetes. The deeper anoxic layers of smooth mats were dominated by Chloroflexi, while Alphaproteobacteria dominated the lower layers of pustular mats. In situ microelectrode measurements revealed smooth mats have a steeper profile of O2 and H2S concentrations, as well as higher oxygen production, consumption, and sulfate reduction rates. Specific elements (Mo, Mg, Mn, Fe, V, P) could be correlated with specific mat types and putative phylogenetic groups. Models are proposed for these systems suggesting putative surface anoxic niches, differential nitrogen fixing niches, and those coupled with methane metabolism.
Collapse
Affiliation(s)
- Hon Lun Wong
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia
- Australian Centre for Astrobiology, University of New South Wales Sydney, Australia
| | - Daniela-Lee Smith
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia
- Australian Centre for Astrobiology, University of New South Wales Sydney, Australia
| | - Pieter T. Visscher
- Department of Marine Sciences, University of Connecticut, USA
- Australian Centre for Astrobiology, University of New South Wales Sydney, Australia
| | - Brendan P. Burns
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia
- Australian Centre for Astrobiology, University of New South Wales Sydney, Australia
| |
Collapse
|
42
|
White RA, Power IM, Dipple GM, Southam G, Suttle CA. Metagenomic analysis reveals that modern microbialites and polar microbial mats have similar taxonomic and functional potential. Front Microbiol 2015; 6:966. [PMID: 26441900 PMCID: PMC4585152 DOI: 10.3389/fmicb.2015.00966] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 08/31/2015] [Indexed: 12/15/2022] Open
Abstract
Within the subarctic climate of Clinton Creek, Yukon, Canada, lies an abandoned and flooded open-pit asbestos mine that harbors rapidly growing microbialites. To understand their formation we completed a metagenomic community profile of the microbialites and their surrounding sediments. Assembled metagenomic data revealed that bacteria within the phylum Proteobacteria numerically dominated this system, although the relative abundances of taxa within the phylum varied among environments. Bacteria belonging to Alphaproteobacteria and Gammaproteobacteria were dominant in the microbialites and sediments, respectively. The microbialites were also home to many other groups associated with microbialite formation including filamentous cyanobacteria and dissimilatory sulfate-reducing Deltaproteobacteria, consistent with the idea of a shared global microbialite microbiome. Other members were present that are typically not associated with microbialites including Gemmatimonadetes and iron-oxidizing Betaproteobacteria, which participate in carbon metabolism and iron cycling. Compared to the sediments, the microbialite microbiome has significantly more genes associated with photosynthetic processes (e.g., photosystem II reaction centers, carotenoid, and chlorophyll biosynthesis) and carbon fixation (e.g., CO dehydrogenase). The Clinton Creek microbialite communities had strikingly similar functional potentials to non-lithifying microbial mats from the Canadian High Arctic and Antarctica, but are functionally distinct, from non-lithifying mats or biofilms from Yellowstone. Clinton Creek microbialites also share metabolic genes (R2 < 0.750) with freshwater microbial mats from Cuatro Ciénegas, Mexico, but are more similar to polar Arctic mats (R2 > 0.900). These metagenomic profiles from an anthropogenic microbialite-forming ecosystem provide context to microbialite formation on a human-relevant timescale.
Collapse
Affiliation(s)
- Richard Allen White
- Department of Microbiology and Immunology, University of British Columbia Vancouver, BC, Canada
| | - Ian M Power
- Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia Vancouver, BC, Canada
| | - Gregory M Dipple
- Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia Vancouver, BC, Canada
| | - Gordon Southam
- School of Earth Sciences, University of Queensland Brisbane, QLD, Australia
| | - Curtis A Suttle
- Department of Microbiology and Immunology, University of British Columbia Vancouver, BC, Canada ; Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia Vancouver, BC, Canada ; Department of Botany, University of British Columbia Vancouver, BC, Canada ; Canadian Institute for Advanced Research Toronto, ON, Canada
| |
Collapse
|
43
|
Miot J, Remusat L, Duprat E, Gonzalez A, Pont S, Poinsot M. Fe biomineralization mirrors individual metabolic activity in a nitrate-dependent Fe(II)-oxidizer. Front Microbiol 2015; 6:879. [PMID: 26441847 PMCID: PMC4562303 DOI: 10.3389/fmicb.2015.00879] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 08/10/2015] [Indexed: 12/15/2022] Open
Abstract
Microbial biomineralization sometimes leads to periplasmic encrustation, which is predicted to enhance microorganism preservation in the fossil record. Mineral precipitation within the periplasm is, however, thought to induce death, as a result of permeability loss preventing nutrient and waste transit across the cell wall. This hypothesis had, however, never been investigated down to the single cell level. Here, we cultured the nitrate reducing Fe(II) oxidizing bacteria Acidovorax sp. strain BoFeN1 that have been previously shown to promote the precipitation of a diversity of Fe minerals (lepidocrocite, goethite, Fe phosphate) encrusting the periplasm. We investigated the connection of Fe biomineralization with carbon assimilation at the single cell level, using a combination of electron microscopy and Nano-Secondary Ion Mass Spectrometry. Our analyses revealed strong individual heterogeneities of Fe biomineralization. Noteworthy, a small proportion of cells remaining free of any precipitate persisted even at advanced stages of biomineralization. Using pulse chase experiments with (13)C-acetate, we provide evidence of individual phenotypic heterogeneities of carbon assimilation, correlated with the level of Fe biomineralization. Whereas non- and moderately encrusted cells were able to assimilate acetate, higher levels of periplasmic encrustation prevented any carbon incorporation. Carbon assimilation only depended on the level of Fe encrustation and not on the nature of Fe minerals precipitated in the cell wall. Carbon assimilation decreased exponentially with increasing cell-associated Fe content. Persistence of a small proportion of non-mineralized and metabolically active cells might constitute a survival strategy in highly ferruginous environments. Eventually, our results suggest that periplasmic Fe biomineralization may provide a signature of individual metabolic status, which could be looked for in the fossil record and in modern environmental samples.
Collapse
Affiliation(s)
- Jennyfer Miot
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Muséum National d’Histoire Naturelle, Université Pierre et Marie Curie – Sorbonne Universités, CNRS UMR 7590, IRD 206Paris, France
| | - Laurent Remusat
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Muséum National d’Histoire Naturelle, Université Pierre et Marie Curie – Sorbonne Universités, CNRS UMR 7590, IRD 206Paris, France
| | - Elodie Duprat
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Muséum National d’Histoire Naturelle, Université Pierre et Marie Curie – Sorbonne Universités, CNRS UMR 7590, IRD 206Paris, France
| | - Adriana Gonzalez
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Muséum National d’Histoire Naturelle, Université Pierre et Marie Curie – Sorbonne Universités, CNRS UMR 7590, IRD 206Paris, France
| | - Sylvain Pont
- Département des Collections, Muséum National d’Histoire NaturelleParis, France
| | - Mélanie Poinsot
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Muséum National d’Histoire Naturelle, Université Pierre et Marie Curie – Sorbonne Universités, CNRS UMR 7590, IRD 206Paris, France
| |
Collapse
|
44
|
Saghaï A, Zivanovic Y, Zeyen N, Moreira D, Benzerara K, Deschamps P, Bertolino P, Ragon M, Tavera R, López-Archilla AI, López-García P. Metagenome-based diversity analyses suggest a significant contribution of non-cyanobacterial lineages to carbonate precipitation in modern microbialites. Front Microbiol 2015; 6:797. [PMID: 26300865 PMCID: PMC4525015 DOI: 10.3389/fmicb.2015.00797] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 07/22/2015] [Indexed: 11/13/2022] Open
Abstract
Cyanobacteria are thought to play a key role in carbonate formation due to their metabolic activity, but other organisms carrying out oxygenic photosynthesis (photosynthetic eukaryotes) or other metabolisms (e.g., anoxygenic photosynthesis, sulfate reduction), may also contribute to carbonate formation. To obtain more quantitative information than that provided by more classical PCR-dependent methods, we studied the microbial diversity of microbialites from the Alchichica crater lake (Mexico) by mining for 16S/18S rRNA genes in metagenomes obtained by direct sequencing of environmental DNA. We studied samples collected at the Western (AL-W) and Northern (AL-N) shores of the lake and, at the latter site, along a depth gradient (1, 5, 10, and 15 m depth). The associated microbial communities were mainly composed of bacteria, most of which seemed heterotrophic, whereas archaea were negligible. Eukaryotes composed a relatively minor fraction dominated by photosynthetic lineages, diatoms in AL-W, influenced by Si-rich seepage waters, and green algae in AL-N samples. Members of the Gammaproteobacteria and Alphaproteobacteria classes of Proteobacteria, Cyanobacteria, and Bacteroidetes were the most abundant bacterial taxa, followed by Planctomycetes, Deltaproteobacteria (Proteobacteria), Verrucomicrobia, Actinobacteria, Firmicutes, and Chloroflexi. Community composition varied among sites and with depth. Although cyanobacteria were the most important bacterial group contributing to the carbonate precipitation potential, photosynthetic eukaryotes, anoxygenic photosynthesizers and sulfate reducers were also very abundant. Cyanobacteria affiliated to Pleurocapsales largely increased with depth. Scanning electron microscopy (SEM) observations showed considerable areas of aragonite-encrusted Pleurocapsa-like cyanobacteria at microscale. Multivariate statistical analyses showed a strong positive correlation of Pleurocapsales and Chroococcales with aragonite formation at macroscale, and suggest a potential causal link. Despite the previous identification of intracellularly calcifying cyanobacteria in Alchichica microbialites, most carbonate precipitation seems extracellular in this system.
Collapse
Affiliation(s)
- Aurélien Saghaï
- Unité d’Ecologie, Systématique et Evolution, CNRS UMR 8079, Université Paris-SudOrsay, France
| | - Yvan Zivanovic
- Institut de Génétique et Microbiologie, CNRS UMR 8621, Université Paris-SudOrsay, France
| | - Nina Zeyen
- Institut de Minéralogie et de Physique des Matériaux et de Cosmochimie, CNRS UMR 7590, Université Pierre et Marie CurieParis, France
| | - David Moreira
- Unité d’Ecologie, Systématique et Evolution, CNRS UMR 8079, Université Paris-SudOrsay, France
| | - Karim Benzerara
- Institut de Minéralogie et de Physique des Matériaux et de Cosmochimie, CNRS UMR 7590, Université Pierre et Marie CurieParis, France
| | - Philippe Deschamps
- Unité d’Ecologie, Systématique et Evolution, CNRS UMR 8079, Université Paris-SudOrsay, France
| | - Paola Bertolino
- Unité d’Ecologie, Systématique et Evolution, CNRS UMR 8079, Université Paris-SudOrsay, France
| | - Marie Ragon
- Unité d’Ecologie, Systématique et Evolution, CNRS UMR 8079, Université Paris-SudOrsay, France
| | - Rosaluz Tavera
- Departamento de Ecología y Recursos Naturales, Universidad Nacional Autónoma de MéxicoMexico City, Mexico
| | | | | |
Collapse
|
45
|
Mobberley JM, Khodadad CLM, Visscher PT, Reid RP, Hagan P, Foster JS. Inner workings of thrombolites: spatial gradients of metabolic activity as revealed by metatranscriptome profiling. Sci Rep 2015. [PMID: 26213359 PMCID: PMC4515876 DOI: 10.1038/srep12601] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Microbialites are sedimentary deposits formed by the metabolic interactions of microbes and their environment. These lithifying microbial communities represent one of the oldest ecosystems on Earth, yet the molecular mechanisms underlying the function of these communities are poorly understood. In this study, we used comparative metagenomic and metatranscriptomic analyses to characterize the spatial organization of the thrombolites of Highborne Cay, The Bahamas, an actively forming microbialite system. At midday, there were differences in gene expression throughout the spatial profile of the thrombolitic mat with a high abundance of transcripts encoding genes required for photosynthesis, nitrogen fixation and exopolymeric substance production in the upper three mm of the mat. Transcripts associated with denitrification and sulfate reduction were in low abundance throughout the depth profile, suggesting these metabolisms were less active during midday. Comparative metagenomics of the Bahamian thrombolites with other known microbialite ecosystems from across the globe revealed that, despite many shared core pathways, the thrombolites represented genetically distinct communities. This study represents the first time the metatranscriptome of living microbialite has been characterized and offers a new molecular perspective on those microbial metabolisms, and their underlying genetic pathways, that influence the mechanisms of carbonate precipitation in lithifying microbial mat ecosystems.
Collapse
Affiliation(s)
- J M Mobberley
- Department of Microbiology and Cell Science, University of Florida, Space Life Science Lab-Exploration Park, Merritt Island, FL 32953
| | - C L M Khodadad
- Department of Microbiology and Cell Science, University of Florida, Space Life Science Lab-Exploration Park, Merritt Island, FL 32953
| | - P T Visscher
- Department of Marine Sciences, University of Connecticut, Groton, CT 06340
| | - R P Reid
- Rosenstiel School of Marine Sciences, University of Miami, Miami, FL, 33149
| | - P Hagan
- Rosenstiel School of Marine Sciences, University of Miami, Miami, FL, 33149
| | - J S Foster
- Department of Microbiology and Cell Science, University of Florida, Space Life Science Lab-Exploration Park, Merritt Island, FL 32953
| |
Collapse
|
46
|
Bacterial Diversity Associated with the Coccolithophorid Algae Emiliania huxleyi and Coccolithus pelagicus f. braarudii. BIOMED RESEARCH INTERNATIONAL 2015; 2015:194540. [PMID: 26273594 PMCID: PMC4529885 DOI: 10.1155/2015/194540] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 01/30/2015] [Indexed: 02/01/2023]
Abstract
Coccolithophores are unicellular calcifying marine phytoplankton that can form large and conspicuous blooms in the oceans and make significant contributions to oceanic carbon cycling and atmospheric CO2 regulation. Despite their importance, the bacterial diversity associated with these algae has not been explored for ecological or biotechnological reasons. Bacterial membership of Emiliania huxleyi and Coccolithus pelagicus f. braarudii cultures was assessed using cultivation and cultivation-independent methods. The communities were species rich compared to other phytoplankton cultures. Community analysis identified specific taxa which cooccur in all cultures (Marinobacter and Marivita). Hydrocarbon-degrading bacteria were found in all cultures. The presence of Acidobacteria, Acidimicrobidae, Schlegelella, and Thermomonas was unprecedented but were potentially explained by calcification associated with coccolith production. One strain of Acidobacteria was cultivated and is closely related to a marine Acidobacteria isolated from a sponge. From this assessment of the bacterial diversity of coccolithophores, a number of biotechnological opportunities are evident, from bioprospecting for novel taxa such as Acidobacteria to helping understand the relationship between obligate hydrocarbonoclastic bacteria occurrence with phytoplankton and to revealing bacterial taxa that have a specific association with algae and may be suitable candidates as a means to improve the efficiency of mass algal cultivation.
Collapse
|
47
|
Ruvindy R, White RA, Neilan BA, Burns BP. Unravelling core microbial metabolisms in the hypersaline microbial mats of Shark Bay using high-throughput metagenomics. ISME JOURNAL 2015; 10:183-96. [PMID: 26023869 DOI: 10.1038/ismej.2015.87] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 04/16/2015] [Accepted: 04/17/2015] [Indexed: 12/31/2022]
Abstract
Modern microbial mats are potential analogues of some of Earth's earliest ecosystems. Excellent examples can be found in Shark Bay, Australia, with mats of various morphologies. To further our understanding of the functional genetic potential of these complex microbial ecosystems, we conducted for the first time shotgun metagenomic analyses. We assembled metagenomic next-generation sequencing data to classify the taxonomic and metabolic potential across diverse morphologies of marine mats in Shark Bay. The microbial community across taxonomic classifications using protein-coding and small subunit rRNA genes directly extracted from the metagenomes suggests that three phyla Proteobacteria, Cyanobacteria and Bacteriodetes dominate all marine mats. However, the microbial community structure between Shark Bay and Highbourne Cay (Bahamas) marine systems appears to be distinct from each other. The metabolic potential (based on SEED subsystem classifications) of the Shark Bay and Highbourne Cay microbial communities were also distinct. Shark Bay metagenomes have a metabolic pathway profile consisting of both heterotrophic and photosynthetic pathways, whereas Highbourne Cay appears to be dominated almost exclusively by photosynthetic pathways. Alternative non-rubisco-based carbon metabolism including reductive TCA cycle and 3-hydroxypropionate/4-hydroxybutyrate pathways is highly represented in Shark Bay metagenomes while not represented in Highbourne Cay microbial mats or any other mat forming ecosystems investigated to date. Potentially novel aspects of nitrogen cycling were also observed, as well as putative heavy metal cycling (arsenic, mercury, copper and cadmium). Finally, archaea are highly represented in Shark Bay and may have critical roles in overall ecosystem function in these modern microbial mats.
Collapse
Affiliation(s)
- Rendy Ruvindy
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, Australia.,Australian Centre for Astrobiology, University of New South Wales, Sydney, New South Wales, Australia
| | | | - Brett Anthony Neilan
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, Australia.,Australian Centre for Astrobiology, University of New South Wales, Sydney, New South Wales, Australia
| | - Brendan Paul Burns
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, Australia.,Australian Centre for Astrobiology, University of New South Wales, Sydney, New South Wales, Australia
| |
Collapse
|
48
|
Coman C, Chiriac CM, Robeson MS, Ionescu C, Dragos N, Barbu-Tudoran L, Andrei AŞ, Banciu HL, Sicora C, Podar M. Structure, mineralogy, and microbial diversity of geothermal spring microbialites associated with a deep oil drilling in Romania. Front Microbiol 2015; 6:253. [PMID: 25870594 PMCID: PMC4378309 DOI: 10.3389/fmicb.2015.00253] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 03/14/2015] [Indexed: 02/01/2023] Open
Abstract
Modern mineral deposits play an important role in evolutionary studies by providing clues to the formation of ancient lithified microbial communities. Here we report the presence of microbialite-forming microbial mats in different microenvironments at 32°C, 49°C, and 65°C around the geothermal spring from an abandoned oil drill in Ciocaia, Romania. The mineralogy and the macro- and microstructure of the microbialites were investigated, together with their microbial diversity based on a 16S rRNA gene amplicon sequencing approach. The calcium carbonate is deposited mainly in the form of calcite. At 32°C and 49°C, the microbialites show a laminated structure with visible microbial mat-carbonate crystal interactions. At 65°C, the mineral deposit is clotted, without obvious organic residues. Partial 16S rRNA gene amplicon sequencing showed that the relative abundance of the phylum Archaea was low at 32°C (<0.5%) but increased significantly at 65°C (36%). The bacterial diversity was either similar to other microbialites described in literature (the 32°C sample) or displayed a specific combination of phyla and classes (the 49°C and 65°C samples). Bacterial taxa were distributed among 39 phyla, out of which 14 had inferred abundances >1%. The dominant bacterial groups at 32°C were Cyanobacteria, Gammaproteobacteria, Firmicutes, Bacteroidetes, Chloroflexi, Thermi, Actinobacteria, Planctomycetes, and Defferibacteres. At 49°C, there was a striking dominance of the Gammaproteobacteria, followed by Firmicutes, Bacteroidetes, and Armantimonadetes. The 65°C sample was dominated by Betaproteobacteria, Firmicutes, [OP1], Defferibacteres, Thermi, Thermotogae, [EM3], and Nitrospirae. Several groups from Proteobacteria and Firmicutes, together with Halobacteria and Melainabacteria were described for the first time in calcium carbonate deposits. Overall, the spring from Ciocaia emerges as a valuable site to probe microbes-minerals interrelationships along thermal and geochemical gradients.
Collapse
Affiliation(s)
- Cristian Coman
- Taxonomy and Ecology, Algology, National Institute of Research and Development for Biological Sciences, Institute of Biological Research Cluj-Napoca, Romania ; Molecular Biology and Biotechnology Department, Faculty of Biology and Geology, Babeş-Bolyai University Cluj-Napoca, Romania
| | - Cecilia M Chiriac
- Taxonomy and Ecology, Algology, National Institute of Research and Development for Biological Sciences, Institute of Biological Research Cluj-Napoca, Romania ; Molecular Biology and Biotechnology Department, Faculty of Biology and Geology, Babeş-Bolyai University Cluj-Napoca, Romania
| | - Michael S Robeson
- Biosciences Division, Oak Ridge National Laboratory Oak Ridge, TN, USA ; Fish, Wildlife, and Conservation Biology, Colorado State University Fort Collins, CO, USA
| | - Corina Ionescu
- Geology Department, Faculty of Biology and Geology, Babeş-Bolyai University Cluj-Napoca, Romania ; Kazan (Volga Region) Federal University Tatarstan, Russia
| | - Nicolae Dragos
- Taxonomy and Ecology, Algology, National Institute of Research and Development for Biological Sciences, Institute of Biological Research Cluj-Napoca, Romania ; Molecular Biology and Biotechnology Department, Faculty of Biology and Geology, Babeş-Bolyai University Cluj-Napoca, Romania
| | - Lucian Barbu-Tudoran
- Electron Microscopy Center, Faculty of Biology and Geology, Babeş-Bolyai University Cluj-Napoca, Romania
| | - Adrian-Ştefan Andrei
- Molecular Biology and Biotechnology Department, Faculty of Biology and Geology, Babeş-Bolyai University Cluj-Napoca, Romania ; Molecular Biology Center, Institute for Interdisciplinary Research on Bio-Nano-Sciences, Babeş-Bolyai University Cluj-Napoca, Romania
| | - Horia L Banciu
- Molecular Biology and Biotechnology Department, Faculty of Biology and Geology, Babeş-Bolyai University Cluj-Napoca, Romania ; Molecular Biology Center, Institute for Interdisciplinary Research on Bio-Nano-Sciences, Babeş-Bolyai University Cluj-Napoca, Romania
| | | | - Mircea Podar
- Biosciences Division, Oak Ridge National Laboratory Oak Ridge, TN, USA
| |
Collapse
|
49
|
Adaptation, ecology, and evolution of the halophilic stromatolite archaeon Halococcus hamelinensis inferred through genome analyses. ARCHAEA-AN INTERNATIONAL MICROBIOLOGICAL JOURNAL 2015; 2015:241608. [PMID: 25709556 PMCID: PMC4325475 DOI: 10.1155/2015/241608] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 12/04/2014] [Accepted: 12/10/2014] [Indexed: 01/26/2023]
Abstract
Halococcus hamelinensis was the first archaeon isolated from stromatolites. These geomicrobial ecosystems are thought to be some of the earliest known on Earth, yet, despite their evolutionary significance, the role of Archaea in these systems is still not well understood. Detailed here is the genome sequencing and analysis of an archaeon isolated from stromatolites. The genome of H. hamelinensis consisted of 3,133,046 base pairs with an average G+C content of 60.08% and contained 3,150 predicted coding sequences or ORFs, 2,196 (68.67%) of which were protein-coding genes with functional assignments and 954 (29.83%) of which were of unknown function. Codon usage of the H. hamelinensis genome was consistent with a highly acidic proteome, a major adaptive mechanism towards high salinity. Amino acid transport and metabolism, inorganic ion transport and metabolism, energy production and conversion, ribosomal structure, and unknown function COG genes were overrepresented. The genome of H. hamelinensis also revealed characteristics reflecting its survival in its extreme environment, including putative genes/pathways involved in osmoprotection, oxidative stress response, and UV damage repair. Finally, genome analyses indicated the presence of putative transposases as well as positive matches of genes of H. hamelinensis against various genomes of Bacteria, Archaea, and viruses, suggesting the potential for horizontal gene transfer.
Collapse
|
50
|
Chan OW, Bugler-Lacap DC, Biddle JF, Lim DS, McKay CP, Pointing SB. Phylogenetic diversity of a microbialite reef in a cold alkaline freshwater lake. Can J Microbiol 2014; 60:391-8. [PMID: 24861562 DOI: 10.1139/cjm-2014-0024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A culture-independent multidomain survey of biodiversity in microbialite structures within the cold alkaline Pavilion Lake (British Columbia, Canada) revealed a largely homogenous community at depths from 10 to 30 m. Real-time quantitative PCR was used to demonstrate that bacteria comprised approximately 80%-95% of recoverable phylotypes. Archaeal phylotypes accounted for <5% of the community in microbialites exposed to the water column, while structures in sediment contact supported 4- to 5-fold higher archaeal abundance. Eukaryal phylotypes were rare and indicated common aquatic diatoms that were concluded not to be part of the microbialite community. Phylogenetic analysis of rRNA genes from clone libraries (N = 491) revealed that alphaproteobacterial phylotypes were most abundant. Cyanobacterial phylotypes were highly diverse but resolved into 4 dominant genera: Acaryochloris, Leptolyngbya, Microcoleus, and Pseudanabaena. Interestingly, microbialite cyanobacteria generally affiliated phylogenetically with aquatic and coral cyanobacterial groups rather than those from stromatolites. Other commonly encountered bacterial phylotypes were from members of the Acidobacteria, with relatively low abundance of the Betaproteobacteria, Chloroflexi, Nitrospirae, and Planctomycetes. Archaeal diversity (N = 53) was largely accounted for by Euryarchaeota, with most phylotypes affiliated with freshwater methanogenic taxa.
Collapse
Affiliation(s)
- Olivia W Chan
- a Institute for Applied Ecology New Zealand, School of Applied Sciences, Auckland University of Technology, Auckland, New Zealand
| | | | | | | | | | | |
Collapse
|