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Astorch-Cardona A, Bertaux L, Denis Y, Dolla A, Rommevaux C. Diversity and dynamics of bacteria from iron-rich microbial mats and colonizers in the Mediterranean Sea (EMSO-Western Ligurian Sea Observatory): Focus on Zetaproteobacteria. PLoS One 2024; 19:e0305626. [PMID: 39008445 PMCID: PMC11249232 DOI: 10.1371/journal.pone.0305626] [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: 01/19/2024] [Accepted: 06/03/2024] [Indexed: 07/17/2024] Open
Abstract
Autotrophic microaerophilic iron-oxidizing Zetaproteobacteria seem to play an important role in mineral weathering and metal corrosion in different environments. Here, we compare the bacterial and zetaproteobacterial communities of a mature iron-rich mat together with in situ incubations of different Fe-bearing materials at the EMSO-Ligure West seafloor observatory, which is located on the abyssal plain in the NW Mediterranean Sea. Our results on bacterial communities enable us to make a clear distinction between those growing on mild steel anthropic substrata and those developing on basaltic substrata. Moreover, on anthropic substrata we highlight an influence of mat age on the bacterial communities. Regarding zetaproteobacterial communities, our results point to an increase in ZetaOTUs abundance and diversification with the age of the mat. We corroborate the key role of the ZetaOTU 2 in mat construction, whatever the environment, the substrata on which they develop or the age of the mat. We also show that ZetaOTU 28 is specific to anthropogenic substrata. Finally, we demonstrate the advantage of using dPCR to precisely quantify very low abundant targets, as Zetaproteobacteria on our colonizers. Our study, also, allows to enrich our knowledge on the biogeography of Zetaproteobacteria, by adding new information on this class and their role in the Mediterranean Sea.
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Affiliation(s)
| | | | - Yann Denis
- Institut de Microbiologie de la Méditerranée, CNRS - Aix Marseille Université, Marseille, France
| | - Alain Dolla
- Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO, Marseille, France
| | - Céline Rommevaux
- Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO, Marseille, France
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2
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Barco RA, Merino N, Lam B, Budnik B, Kaplan M, Wu F, Amend JP, Nealson KH, Emerson D. Comparative proteomics of a versatile, marine, iron-oxidizing chemolithoautotroph. Environ Microbiol 2024; 26:e16632. [PMID: 38861374 DOI: 10.1111/1462-2920.16632] [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: 01/08/2024] [Accepted: 04/20/2024] [Indexed: 06/13/2024]
Abstract
This study conducted a comparative proteomic analysis to identify potential genetic markers for the biological function of chemolithoautotrophic iron oxidation in the marine bacterium Ghiorsea bivora. To date, this is the only characterized species in the class Zetaproteobacteria that is not an obligate iron-oxidizer, providing a unique opportunity to investigate differential protein expression to identify key genes involved in iron-oxidation at circumneutral pH. Over 1000 proteins were identified under both iron- and hydrogen-oxidizing conditions, with differentially expressed proteins found in both treatments. Notably, a gene cluster upregulated during iron oxidation was identified. This cluster contains genes encoding for cytochromes that share sequence similarity with the known iron-oxidase, Cyc2. Interestingly, these cytochromes, conserved in both Bacteria and Archaea, do not exhibit the typical β-barrel structure of Cyc2. This cluster potentially encodes a biological nanowire-like transmembrane complex containing multiple redox proteins spanning the inner membrane, periplasm, outer membrane, and extracellular space. The upregulation of key genes associated with this complex during iron-oxidizing conditions was confirmed by quantitative reverse transcription-PCR. These findings were further supported by electromicrobiological methods, which demonstrated negative current production by G. bivora in a three-electrode system poised at a cathodic potential. This research provides significant insights into the biological function of chemolithoautotrophic iron oxidation.
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Affiliation(s)
- Roman A Barco
- Department of Earth Sciences, University of Southern California, Los Angeles, California, USA
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
- Bigelow Laboratory for Ocean Sciences, East Boothbay, Maine, USA
| | - N Merino
- Department of Earth Sciences, University of Southern California, Los Angeles, California, USA
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
- Lawrence Livermore National Lab, Biosciences and Biotechnology Division, Livermore, California, USA
| | - B Lam
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - B Budnik
- Mass Spectrometry and Proteomics Resource Laboratory, Harvard University, Cambridge, Massachusetts, USA
| | - M Kaplan
- Department of Microbiology, University of Chicago, Chicago, Illinois, USA
| | - F Wu
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou, Zhejiang, China
| | - J P Amend
- Department of Earth Sciences, University of Southern California, Los Angeles, California, USA
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - K H Nealson
- Department of Earth Sciences, University of Southern California, Los Angeles, California, USA
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - D Emerson
- Bigelow Laboratory for Ocean Sciences, East Boothbay, Maine, USA
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Baker IR, Girguis PR. Sulfur cycling likely obscures dynamic biologically-driven iron redox cycling in contemporary methane seep environments. ENVIRONMENTAL MICROBIOLOGY REPORTS 2024; 16:e13263. [PMID: 38705733 PMCID: PMC11070330 DOI: 10.1111/1758-2229.13263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Accepted: 04/06/2024] [Indexed: 05/07/2024]
Abstract
Deep-sea methane seeps are amongst the most biologically productive environments on Earth and are often characterised by stable, low oxygen concentrations and microbial communities that couple the anaerobic oxidation of methane to sulfate reduction or iron reduction in the underlying sediment. At these sites, ferrous iron (Fe2+) can be produced by organoclastic iron reduction, methanotrophic-coupled iron reduction, or through the abiotic reduction by sulfide produced by the abundant sulfate-reducing bacteria at these sites. The prevalence of Fe2+in the anoxic sediments, as well as the availability of oxygen in the overlying water, suggests that seeps could also harbour communities of iron-oxidising microbes. However, it is unclear to what extent Fe2+ remains bioavailable and in solution given that the abiotic reaction between sulfide and ferrous iron is often assumed to scavenge all ferrous iron as insoluble iron sulfides and pyrite. Accordingly, we searched the sea floor at methane seeps along the Cascadia Margin for microaerobic, neutrophilic iron-oxidising bacteria, operating under the reasoning that if iron-oxidising bacteria could be isolated from these environments, it could indicate that porewater Fe2+ can persist is long enough for biology to outcompete pyritisation. We found that the presence of sulfate in our enrichment media muted any obvious microbially-driven iron oxidation with most iron being precipitated as iron sulfides. Transfer of enrichment cultures to sulfate-depleted media led to dynamic iron redox cycling relative to abiotic controls and sulfate-containing cultures, and demonstrated the capacity for biogenic iron (oxyhydr)oxides from a methane seep-derived community. 16S rRNA analyses revealed that removing sulfate drastically reduced the diversity of enrichment cultures and caused a general shift from a Gammaproteobacteria-domainated ecosystem to one dominated by Rhodobacteraceae (Alphaproteobacteria). Our data suggest that, in most cases, sulfur cycling may restrict the biological "ferrous wheel" in contemporary environments through a combination of the sulfur-adapted sediment-dwelling ecosystems and the abiotic reactions they influence.
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Affiliation(s)
- Isabel R. Baker
- Department of Organismic and Evolutionary BiologyHarvard UniversityCambridgeMassachusettsUSA
- Department of Earth and Planetary ScienceJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Peter R. Girguis
- Department of Organismic and Evolutionary BiologyHarvard UniversityCambridgeMassachusettsUSA
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Astorch-Cardona A, Odin GP, Chavagnac V, Dolla A, Gaussier H, Rommevaux C. Linking Zetaproteobacterial diversity and substratum type in iron-rich microbial mats from the Lucky Strike hydrothermal field (EMSO-Azores observatory). Appl Environ Microbiol 2024; 90:e0204123. [PMID: 38193671 PMCID: PMC10880625 DOI: 10.1128/aem.02041-23] [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: 11/15/2023] [Accepted: 12/01/2023] [Indexed: 01/10/2024] Open
Abstract
Zetaproteobacteria have been reported in different marine and terrestrial environments all over the globe. They play an essential role in marine iron-rich microbial mats, as one of their autotrophic primary producers, oxidizing Fe(II) and producing Fe-oxyhydroxides with different morphologies. Here, we study and compare the Zetaproteobacterial communities of iron-rich microbial mats from six different sites of the Lucky Strike Hydrothermal Field through the use of the Zetaproteobacterial operational taxonomic unit (ZetaOTU) classification. We report for the first time the Zetaproteobacterial core microbiome of these iron-rich microbial mats, which is composed of four ZetaOTUs that are cosmopolitan and essential for the development of the mats. The study of the presence and abundance of different ZetaOTUs among sites reveals two clusters, which are related to the lithology and permeability of the substratum on which they develop. The Zetaproteobacterial communities of cluster 1 are characteristic of poorly permeable substrata, with little evidence of diffuse venting, while those of cluster 2 develop on hydrothermal slabs or deposits that allow the percolation and outflow of diffuse hydrothermal fluids. In addition, two NewZetaOTUs 1 and 2 were identified, which could be characteristic of anthropic iron and unsedimented basalt, respectively. We also report significant correlations between the abundance of certain ZetaOTUs and that of iron oxide morphologies, indicating that their formation could be taxonomically and/or environmentally driven. We identified a new morphology of Fe(III)-oxyhydroxides that we named "corals." Overall, our work contributes to the knowledge of the biogeography of this bacterial class by providing additional data from the Atlantic Ocean, a lesser-studied ocean in terms of Zetaproteobacterial diversity.IMPORTANCEUp until now, Zetaproteobacterial diversity studies have revealed possible links between Zetaproteobacteria taxa, habitats, and niches. Here, we report for the first time the Zetaproteobacterial core microbiome of iron-rich mats from the Lucky Strike Hydrothermal Field (LSHF), as well as two new Zetaproteobacterial operational taxonomic units (NewZetaOTUs) that could be substratum specific. We highlight that the substratum on which iron-rich microbial mats develop, especially because of its permeability to diffuse hydrothermal venting, has an influence on their Zetaproteobacterial communities. Moreover, our work adds to the knowledge of the biogeography of this bacterial class by providing additional data from the hydrothermal vent sites along the Mid-Atlantic Ridge. In addition to the already described iron oxide morphologies, we identify in our iron-rich mats a new morphology that we named corals. Finally, we argue for significant correlations between the relative abundance of certain ZetaOTUs and that of iron oxide morphologies, contributing to the understanding of the drivers of iron oxide production in iron-oxidizing bacteria.
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Affiliation(s)
- Aina Astorch-Cardona
- Aix-Marseille University, Université de Toulon, CNRS, IRD, MIO, Marseille, France
| | - Giliane P. Odin
- Laboratoire Géomatériaux et Environnement, Université Gustave Eiffel, Marne-la-Vallée, France
| | - Valérie Chavagnac
- Géosciences Environnement Toulouse, CNRS UMR 5563 (CNRS/UPS/IRD/CNES), Université de Toulouse, Observatoire Midi-Pyrénées, Toulouse, France
| | - Alain Dolla
- Aix-Marseille University, Université de Toulon, CNRS, IRD, MIO, Marseille, France
| | - Hélène Gaussier
- Aix-Marseille University, Université de Toulon, CNRS, IRD, MIO, Marseille, France
| | - Céline Rommevaux
- Aix-Marseille University, Université de Toulon, CNRS, IRD, MIO, Marseille, France
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Fullerton H, Smith L, Enriquez A, Butterfield D, Wheat CG, Moyer CL. Seafloor incubation experiments at deep-sea hydrothermal vents reveal distinct biogeographic signatures of autotrophic communities. FEMS Microbiol Ecol 2024; 100:fiae001. [PMID: 38200713 PMCID: PMC10808952 DOI: 10.1093/femsec/fiae001] [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: 05/23/2023] [Revised: 10/20/2023] [Accepted: 01/09/2024] [Indexed: 01/12/2024] Open
Abstract
The discharge of hydrothermal vents on the seafloor provides energy sources for dynamic and productive ecosystems, which are supported by chemosynthetic microbial populations. These populations use the energy gained by oxidizing the reduced chemicals contained within the vent fluids to fix carbon and support multiple trophic levels. Hydrothermal discharge is ephemeral and chemical composition of such fluids varies over space and time, which can result in geographically distinct microbial communities. To investigate the foundational members of the community, microbial growth chambers were placed within the hydrothermal discharge at Axial Seamount (Juan de Fuca Ridge), Magic Mountain Seamount (Explorer Ridge), and Kama'ehuakanaloa Seamount (Hawai'i hotspot). Campylobacteria were identified within the nascent communities, but different amplicon sequence variants were present at Axial and Kama'ehuakanaloa Seamounts, indicating that geography in addition to the composition of the vent effluent influences microbial community development. Across these vent locations, dissolved iron concentration was the strongest driver of community structure. These results provide insights into nascent microbial community structure and shed light on the development of diverse lithotrophic communities at hydrothermal vents.
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Affiliation(s)
- Heather Fullerton
- Department of Biology, College of Charleston, 66 George Street, Charleston, SC 29424, United States
| | - Lindsey Smith
- Department of Biology, Western Washington University, 516 High St, Bellingham, WA 98225, United States
| | - Alejandra Enriquez
- Department of Biology, College of Charleston, 66 George Street, Charleston, SC 29424, United States
| | - David Butterfield
- Cooperative Institute for Climate, Ocean, and Ecosystem Studies, University of Washington and NOAA/PMEL, John M. Wallace Hall, 3737 Brooklyn Ave NE, Seattle, WA 98105, United States
| | - C Geoffrey Wheat
- Institute of Marine Studies, College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, 2150 Koyukuk Drive, 245 O’Neill Building, PO Box 757220, Fairbanks, Alaska 99775-7220, United States
| | - Craig L Moyer
- Department of Biology, Western Washington University, 516 High St, Bellingham, WA 98225, United States
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Hribovšek P, Olesin Denny E, Dahle H, Mall A, Øfstegaard Viflot T, Boonnawa C, Reeves EP, Steen IH, Stokke R. Putative novel hydrogen- and iron-oxidizing sheath-producing Zetaproteobacteria thrive at the Fåvne deep-sea hydrothermal vent field. mSystems 2023; 8:e0054323. [PMID: 37921472 PMCID: PMC10734525 DOI: 10.1128/msystems.00543-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 10/02/2023] [Indexed: 11/04/2023] Open
Abstract
IMPORTANCE Knowledge on microbial iron oxidation is important for understanding the cycling of iron, carbon, nitrogen, nutrients, and metals. The current study yields important insights into the niche sharing, diversification, and Fe(III) oxyhydroxide morphology of Ghiorsea, an iron- and hydrogen-oxidizing Zetaproteobacteria representative belonging to Zetaproteobacteria operational taxonomic unit 9. The study proposes that Ghiorsea exhibits a more extensive morphology of Fe(III) oxyhydroxide than previously observed. Overall, the results increase our knowledge on potential drivers of Zetaproteobacteria diversity in iron microbial mats and can eventually be used to develop strategies for the cultivation of sheath-forming Zetaproteobacteria.
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Affiliation(s)
- Petra Hribovšek
- Centre for Deep Sea Research, University of Bergen, Bergen, Norway
- Department of Earth Science, University of Bergen, Bergen, Norway
| | - Emily Olesin Denny
- Centre for Deep Sea Research, University of Bergen, Bergen, Norway
- Department of Biological Sciences, University of Bergen, Bergen, Norway
- Computational Biology Unit, University of Berge, Bergen, Norway
| | - Håkon Dahle
- Centre for Deep Sea Research, University of Bergen, Bergen, Norway
- Department of Biological Sciences, University of Bergen, Bergen, Norway
- Computational Biology Unit, University of Berge, Bergen, Norway
| | - Achim Mall
- Centre for Deep Sea Research, University of Bergen, Bergen, Norway
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Thomas Øfstegaard Viflot
- Centre for Deep Sea Research, University of Bergen, Bergen, Norway
- Department of Earth Science, University of Bergen, Bergen, Norway
| | - Chanakan Boonnawa
- Centre for Deep Sea Research, University of Bergen, Bergen, Norway
- Department of Earth Science, University of Bergen, Bergen, Norway
| | - Eoghan P. Reeves
- Centre for Deep Sea Research, University of Bergen, Bergen, Norway
- Department of Earth Science, University of Bergen, Bergen, Norway
| | - Ida Helene Steen
- Centre for Deep Sea Research, University of Bergen, Bergen, Norway
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Runar Stokke
- Centre for Deep Sea Research, University of Bergen, Bergen, Norway
- Department of Biological Sciences, University of Bergen, Bergen, Norway
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7
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Chan CS, Dykes GE, Hoover RL, Limmer MA, Seyfferth AL. Gallionellaceae in rice root plaque: metabolic roles in iron oxidation, nutrient cycling, and plant interactions. Appl Environ Microbiol 2023; 89:e0057023. [PMID: 38009924 PMCID: PMC10734482 DOI: 10.1128/aem.00570-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 09/18/2023] [Indexed: 11/29/2023] Open
Abstract
IMPORTANCE In waterlogged soils, iron plaque forms a reactive barrier between the root and soil, collecting phosphate and metals such as arsenic and cadmium. It is well established that iron-reducing bacteria solubilize iron, releasing these associated elements. In contrast, microbial roles in plaque formation have not been clear. Here, we show that there is a substantial population of iron oxidizers in plaque, and furthermore, that these organisms (Sideroxydans and Gallionella) are distinguished by genes for plant colonization and nutrient fixation. Our results suggest that iron-oxidizing and iron-reducing bacteria form and remodel iron plaque, making it a dynamic system that represents both a temporary sink for elements (P, As, Cd, C, etc.) as well as a source. In contrast to abiotic iron oxidation, microbial iron oxidation results in coupled Fe-C-N cycling, as well as microbe-microbe and microbe-plant ecological interactions that need to be considered in soil biogeochemistry, ecosystem dynamics, and crop management.
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Affiliation(s)
- Clara S. Chan
- Department of Earth Sciences, University of Delaware, Newark, Delaware, USA
- School of Marine Science and Policy, University of Delaware, Newark, Delaware, USA
- Microbiology Graduate Program, University of Delaware, Newark, Delaware, USA
- Delaware Biotechnology Institute, Newark, Delaware, USA
| | - Gretchen E. Dykes
- Microbiology Graduate Program, University of Delaware, Newark, Delaware, USA
- Delaware Biotechnology Institute, Newark, Delaware, USA
- Department of Plant and Soil Sciences, University of Delaware, Newark, Delaware, USA
| | - Rene L. Hoover
- Department of Earth Sciences, University of Delaware, Newark, Delaware, USA
- Microbiology Graduate Program, University of Delaware, Newark, Delaware, USA
- Delaware Biotechnology Institute, Newark, Delaware, USA
| | - Matt A. Limmer
- Department of Plant and Soil Sciences, University of Delaware, Newark, Delaware, USA
| | - Angelia L. Seyfferth
- Department of Earth Sciences, University of Delaware, Newark, Delaware, USA
- Department of Plant and Soil Sciences, University of Delaware, Newark, Delaware, USA
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Baker IR, Matzen SL, Schuler CJ, Toner BM, Girguis PR. Aerobic iron-oxidizing bacteria secrete metabolites that markedly impede abiotic iron oxidation. PNAS NEXUS 2023; 2:pgad421. [PMID: 38111821 PMCID: PMC10727123 DOI: 10.1093/pnasnexus/pgad421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 11/29/2023] [Indexed: 12/20/2023]
Abstract
Iron is one of the Earth's most abundant elements and is required for essentially all forms of life. Yet, iron's reactivity with oxygen and poor solubility in its oxidized form (Fe3+) mean that it is often a limiting nutrient in oxic, near-neutral pH environments like Earth's ocean. In addition to being a vital nutrient, there is a diversity of aerobic organisms that oxidize ferrous iron (Fe2+) to harness energy for growth and biosynthesis. Accordingly, these organisms rely on access to co-existing Fe2+ and O2 to survive. It is generally presumed that such aerobic iron-oxidizing bacteria (FeOB) are relegated to low-oxygen regimes where abiotic iron oxidation rates are slower, yet some FeOB live in higher oxygen environments where they cannot rely on lower oxygen concentrations to overcome abiotic competition. We hypothesized that FeOB chemically alter their environment to limit abiotic interactions between Fe2+ and O2. To test this, we incubated the secreted metabolites (collectively known as the exometabolome) of the deep-sea iron- and hydrogen-oxidizing bacterium Ghiorsea bivora TAG-1 with ferrous iron and oxygen. We found that this FeOB's iron-oxidizing exometabolome markedly impedes the abiotic oxidation of ferrous iron, increasing the half-life of Fe2+ 100-fold from ∼3 to ∼335 days in the presence of O2, while the exometabolome of TAG-1 grown on hydrogen had no effect. Moreover, the few precipitates that formed in the presence of TAG-1's iron-oxidizing exometabolome were poorly crystalline, compared with the abundant iron particles that mineralized in the absence of abiotic controls. We offer an initial exploration of TAG-1's iron-oxidizing exometabolome and discuss potential key contributors to this process. Overall, our findings demonstrate that the exometabolome as a whole leads to a sustained accumulation of ferrous iron in the presence of oxygen, consequently altering the redox equilibrium. This previously unknown adaptation likely enables these microorganisms to persist in an iron-oxidizing and iron-precipitating world and could have impacts on the bioavailability of iron to FeOB and other life in iron-limiting environments.
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Affiliation(s)
- Isabel R Baker
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Sarick L Matzen
- Department of Soil, Water, and Climate, University of Minnesota Twin Cities, Saint Paul, MN 55108, USA
| | - Christopher J Schuler
- Department of Earth and Environmental Sciences, University of Minnesota Twin Cities, Saint Paul, MN 55108, USA
| | - Brandy M Toner
- Department of Soil, Water, and Climate, University of Minnesota Twin Cities, Saint Paul, MN 55108, USA
- Department of Earth and Environmental Sciences, University of Minnesota Twin Cities, Saint Paul, MN 55108, USA
| | - Peter R Girguis
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
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Zhang S, Hill RT, Wang H. Genomic characterization and molecular dating of the novel bacterium Permianibacter aggregans HW001 T, which originated from Permian ground water. MARINE LIFE SCIENCE & TECHNOLOGY 2023; 5:12-27. [PMID: 37077290 PMCID: PMC10077173 DOI: 10.1007/s42995-023-00164-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 12/28/2022] [Indexed: 05/03/2023]
Abstract
The Permian Basin is a unique ecosystem located in the southwest of the USA. An unanswered question is whether the bacteria in the Permian Basin adapted to the changing paleomarine environment and survived in the remnants of Permian groundwater. In our previous study, a novel bacterial strain, Permianibacter aggregans HW001T, was isolated from microalgae cultures incubated with Permian Basin waters, and was shown to originate from the Permian Ocean. In this study, strain HW001T was shown to be the representative strain of a novel family, classified as 'Permianibacteraceae'. The results of molecular dating suggested that the strain HW001T diverged ~ 447 million years ago (mya), which is the early Permian period (~ 250 mya). Genome analysis was used to access its potential energy utilization and biosynthesis capacity. A large number of transporters, carbohydrate-active enzymes and protein-degradation related genes have been annotated in the genome of strain HW001T. In addition, a series of important metabolic pathways, such as peptidoglycan biosynthesis, osmotic stress response system and multifunctional quorum sensing were annotated, which may confer the ability to adapt to various unfavorable environmental conditions. Finally, the evolutionary history of strain HW001T was reconstructed and the horizontal transfer of genes was predicted, indicating that the adaptation of P. aggregans to a changing marine environment depends on the evolution of their metabolic capabilities, especially in signal transmission. In conclusion, the results of this study provide genomic information for revealing the adaptive mechanism of strain HW001T to the changing ancient oceans. Supplementary Information The online version contains supplementary material available at 10.1007/s42995-023-00164-3.
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Affiliation(s)
- Shuangfei Zhang
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458 China
- Biology Department, College of Science, and Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, 515063 China
| | - Russell T. Hill
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, Baltimore, MD 21201 USA
| | - Hui Wang
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458 China
- Biology Department, College of Science, and Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, 515063 China
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10
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He Y, Zeng X, Xu F, Shao Z. Diversity of Mixotrophic Neutrophilic Thiosulfate- and Iron-Oxidizing Bacteria from Deep-Sea Hydrothermal Vents. Microorganisms 2022; 11:microorganisms11010100. [PMID: 36677390 PMCID: PMC9861301 DOI: 10.3390/microorganisms11010100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 12/22/2022] [Accepted: 12/22/2022] [Indexed: 01/04/2023] Open
Abstract
At deep-sea hydrothermal vents, sulfur oxidation and iron oxidation are of the highest importance to microbial metabolisms, which are thought to contribute mainly in chemolithoautotrophic groups. In this study, 17 mixotrophic neutrophilic thiosulfate- and iron-oxidizing bacteria were isolated from hydrothermal fields on the Carlsberg Ridge in the Indian Ocean, nine to the γ-proteobacteria (Halomonas (4), Pseudomonas (2), Marinobacter (2), and Rheinheimera (1)), seven to the α-proteobacteria (Thalassospira, Qipengyuania, Salipiger, Seohaeicola, Martelella, Citromicrobium, and Aurantimonas), and one to the Actinobacteria (Agromyces), as determined by their 16S rRNA and genome sequences. The physiological characterization of these isolates revealed wide versatility in electron donors (Fe(II) and Mn(II), or thiosulfate) and a variety of lifestyles as lithotrophic or heterotrophic, microaerobic, or anaerobic. As a representative strain, Pseudomonas sp. IOP_13 showed its autotrophic gowth from 105 cells/ml to 107 cells/ml;carbon dioxide fixation capacity with the δ13CVPDB in the biomass increased from -27.42‱ to 3460.06‱; the thiosulfate-oxidizing ability with produced SO42- increased from 60 mg/L to 287 mg/L; and the iron-oxidizing ability with Fe(II) decreased from 10 mM to 5.2 mM. In addition, iron-oxide crust formed outside the cells. Gene coding for energy metabolism involved in possible iron, manganese, and sulfur oxidation, and denitrification was identified by their genome analysis. This study sheds light on the function of the mixotrophic microbial community in the iron/manganese/sulfur cycles and the carbon fixation of the hydrothermal fields.
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11
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Zhong YW, Zhou P, Cheng H, Zhou YD, Pan J, Xu L, Li M, Tao CH, Wu YH, Xu XW. Metagenomic Features Characterized with Microbial Iron Oxidoreduction and Mineral Interaction in Southwest Indian Ridge. Microbiol Spectr 2022; 10:e0061422. [PMID: 36286994 PMCID: PMC9769843 DOI: 10.1128/spectrum.00614-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 07/25/2022] [Indexed: 01/05/2023] Open
Abstract
The Southwest Indian Ridge (SWIR) is one of the typical representatives of deep-sea ultraslow-spreading ridges, and has increasingly become a hot spot of studying subsurface geological activities and deep-sea mining management. However, the understanding of microbial activities is still limited on active hydrothermal vent chimneys in SWIR. In this study, samples from an active black smoker and a diffuse vent located in the Longqi hydrothermal region were collected for deep metagenomic sequencing, which yielded approximately 290 GB clean data and 295 mid-to-high-quality metagenome-assembled genomes (MAGs). Sulfur oxidation conducted by a variety of Gammaproteobacteria, Alphaproteobacteria, and Campylobacterota was presumed to be the major energy source for chemosynthesis in Longqi hydrothermal vents. Diverse iron-related microorganisms were recovered, including iron-oxidizing Zetaproteobacteria, iron-reducing Deferrisoma, and magnetotactic bacterium. Twenty-two bacterial MAGs from 12 uncultured phyla harbored iron oxidase Cyc2 homologs and enzymes for organic carbon degradation, indicated novel chemolithoheterotrophic iron-oxidizing bacteria that affected iron biogeochemistry in hydrothermal vents. Meanwhile, potential interactions between microbial communities and chimney minerals were emphasized as enriched metabolic potential of siderophore transportation, and extracellular electron transfer functioned by multi-heme proteins was discovered. Composition of chimney minerals probably affected microbial iron metabolic potential, as pyrrhotite might provide more available iron for microbial communities. Collectively, this study provides novel insights into microbial activities and potential mineral-microorganism interactions in hydrothermal vents. IMPORTANCE Microbial activities and interactions with minerals and venting fluid in active hydrothermal vents remain unclear in the ultraslow-spreading SWIR (Southwest Indian Ridge). Understanding about how minerals influence microbial metabolism is currently limited given the obstacles in cultivating microorganisms with sulfur or iron oxidoreduction functions. Here, comprehensive descriptions on microbial composition and metabolic profile on 2 hydrothermal vents in SWIR were obtained based on cultivation-free metagenome sequencing. In particular, autotrophic sulfur oxidation supported by minerals was presumed, emphasizing the role of chimney minerals in supporting chemosynthesis. Presence of novel heterotrophic iron-oxidizing bacteria was also indicated, suggesting overlooked biogeochemical pathways directed by microorganisms that connected sulfide mineral dissolution and organic carbon degradation in hydrothermal vents. Our findings offer novel insights into microbial function and biotic interactions on minerals in ultraslow-spreading ridges.
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Affiliation(s)
- Ying-Wen Zhong
- School of Oceanography, Shanghai Jiao Tong University, Shanghai, PR China
- Key Laboratory of Marine Ecosystem Dynamics, Ministry of Natural Resources & Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, PR China
| | - Peng Zhou
- Key Laboratory of Marine Ecosystem Dynamics, Ministry of Natural Resources & Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, PR China
| | - Hong Cheng
- Key Laboratory of Marine Ecosystem Dynamics, Ministry of Natural Resources & Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, PR China
| | - Ya-Dong Zhou
- Key Laboratory of Marine Ecosystem Dynamics, Ministry of Natural Resources & Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, PR China
| | - Jie Pan
- Archaeal Biology Center, Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, PR China
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, PR China
| | - Lin Xu
- Key Laboratory of Marine Ecosystem Dynamics, Ministry of Natural Resources & Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, PR China
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, PR China
| | - Meng Li
- Archaeal Biology Center, Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, PR China
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, PR China
| | - Chun-Hui Tao
- School of Oceanography, Shanghai Jiao Tong University, Shanghai, PR China
- Key Laboratory of Submarine Geosciences, Ministry of Natural Resources & Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, PR China
| | - Yue-Hong Wu
- School of Oceanography, Shanghai Jiao Tong University, Shanghai, PR China
- Key Laboratory of Marine Ecosystem Dynamics, Ministry of Natural Resources & Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, PR China
| | - Xue-Wei Xu
- School of Oceanography, Shanghai Jiao Tong University, Shanghai, PR China
- Key Laboratory of Marine Ecosystem Dynamics, Ministry of Natural Resources & Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, PR China
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12
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D’Angelo T, Goordial J, Poulton NJ, Seyler L, Huber JA, Stepanauskas R, Orcutt BN. Oceanic Crustal Fluid Single Cell Genomics Complements Metagenomic and Metatranscriptomic Surveys With Orders of Magnitude Less Sample Volume. Front Microbiol 2022; 12:738231. [PMID: 35140689 PMCID: PMC8819061 DOI: 10.3389/fmicb.2021.738231] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 11/30/2021] [Indexed: 12/22/2022] Open
Abstract
Fluids circulating through oceanic crust play important roles in global biogeochemical cycling mediated by their microbial inhabitants, but studying these sites is challenged by sampling logistics and low biomass. Borehole observatories installed at the North Pond study site on the western flank of the Mid-Atlantic Ridge have enabled investigation of the microbial biosphere in cold, oxygenated basaltic oceanic crust. Here we test a methodology that applies redox-sensitive fluorescent molecules for flow cytometric sorting of cells for single cell genomic sequencing from small volumes of low biomass (approximately 103 cells ml-1) crustal fluid. We compare the resulting genomic data to a recently published paired metagenomic and metatranscriptomic analysis from the same site. Even with low coverage genome sequencing, sorting cells from less than one milliliter of crustal fluid results in similar interpretation of dominant taxa and functional profiles as compared to 'omics analysis that typically filter orders of magnitude more fluid volume. The diverse community dominated by Gammaproteobacteria, Bacteroidetes, Desulfobacterota, Alphaproteobacteria, and Zetaproteobacteria, had evidence of autotrophy and heterotrophy, a variety of nitrogen and sulfur cycling metabolisms, and motility. Together, results indicate fluorescence activated cell sorting methodology is a powerful addition to the toolbox for the study of low biomass systems or at sites where only small sample volumes are available for analysis.
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Affiliation(s)
- Timothy D’Angelo
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, United States
| | - Jacqueline Goordial
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, United States
- School of Environmental Sciences, University of Guelph, Guelph, ON, Canada
| | - Nicole J. Poulton
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, United States
| | - Lauren Seyler
- School of Natural Science and Mathematics, Stockton University, Galloway, NJ, United States
- Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, United States
| | - Julie A. Huber
- Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, United States
| | | | - Beth N. Orcutt
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, United States
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13
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Rajala P, Cheng DQ, Rice SA, Lauro FM. Sulfate-dependant microbially induced corrosion of mild steel in the deep sea: a 10-year microbiome study. MICROBIOME 2022; 10:4. [PMID: 35027090 PMCID: PMC8756651 DOI: 10.1186/s40168-021-01196-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 11/13/2021] [Indexed: 06/14/2023]
Abstract
BACKGROUND Metal corrosion in seawater has been extensively studied in surface and shallow waters. However, infrastructure is increasingly being installed in deep-sea environments, where extremes of temperature, salinity, and high hydrostatic pressure increase the costs and logistical challenges associated with monitoring corrosion. Moreover, there is currently only a rudimentary understanding of the role of microbially induced corrosion, which has rarely been studied in the deep-sea. We report here an integrative study of the biofilms growing on the surface of corroding mooring chain links that had been deployed for 10 years at ~2 km depth and developed a model of microbially induced corrosion based on flux-balance analysis. METHODS We used optical emission spectrometry to analyze the chemical composition of the mooring chain and energy-dispersive X-ray spectrometry coupled with scanning electron microscopy to identify corrosion products and ultrastructural features. The taxonomic structure of the microbiome was determined using shotgun metagenomics and was confirmed by 16S amplicon analysis and quantitative PCR of the dsrB gene. The functional capacity was further analyzed by generating binned, genomic assemblies and performing flux-balance analysis on the metabolism of the dominant taxa. RESULTS The surface of the chain links showed intensive and localized corrosion with structural features typical of microbially induced corrosion. The microbiome on the links differed considerably from that of the surrounding sediment, suggesting selection for specific metal-corroding biofilms dominated by sulfur-cycling bacteria. The core metabolism of the microbiome was reconstructed to generate a mechanistic model that combines biotic and abiotic corrosion. Based on this metabolic model, we propose that sulfate reduction and sulfur disproportionation might play key roles in deep-sea corrosion. CONCLUSIONS The corrosion rate observed was higher than what could be expected from abiotic corrosion mechanisms under these environmental conditions. High corrosion rate and the form of corrosion (deep pitting) suggest that the corrosion of the chain links was driven by both abiotic and biotic processes. We posit that the corrosion is driven by deep-sea sulfur-cycling microorganisms which may gain energy by accelerating the reaction between metallic iron and elemental sulfur. The results of this field study provide important new insights on the ecophysiology of the corrosion process in the deep sea.
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Affiliation(s)
- Pauliina Rajala
- Singapore Centre for Environmental Life Sciences Engineering/Nanyang Technological University, 60 Nanyang Dr, Singapore, 637551 Singapore
- VTT Technical Research Centre of Finland Ltd., Materials in Extreme Environments, Kemistintie 3, 02044-VTT Espoo, Finland
| | - Dong-Qiang Cheng
- Singapore Centre for Environmental Life Sciences Engineering/Nanyang Technological University, 60 Nanyang Dr, Singapore, 637551 Singapore
| | - Scott A. Rice
- Singapore Centre for Environmental Life Sciences Engineering/Nanyang Technological University, 60 Nanyang Dr, Singapore, 637551 Singapore
- The School of Biological Sciences, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798 Singapore
- ithree Institute, The University of Technology Sydney, Ultimo, Australia
| | - Federico M. Lauro
- Singapore Centre for Environmental Life Sciences Engineering/Nanyang Technological University, 60 Nanyang Dr, Singapore, 637551 Singapore
- Asian School of the Environment, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798 Singapore
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14
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Abstract
Iron (Fe) oxidation is one of Earth’s major biogeochemical processes, key to weathering, soil formation, water quality, and corrosion. However, our understanding of microbial contribution is limited by incomplete knowledge of microbial iron oxidation mechanisms, particularly in neutrophilic iron oxidizers. The genomes of many diverse iron oxidizers encode a homolog to an outer membrane cytochrome (Cyc2) shown to oxidize iron in two acidophiles. Phylogenetic analyses show Cyc2 sequences from neutrophiles cluster together, suggesting a common function, though this function has not been verified in these organisms. Therefore, we investigated the iron oxidase function of heterologously expressed Cyc2 from a neutrophilic iron oxidizer Mariprofundus ferrooxydans PV-1. Cyc2PV-1 is capable of oxidizing iron, and its redox potential is 208 ± 20 mV, consistent with the ability to accept electrons from Fe2+ at neutral pH. These results support the hypothesis that Cyc2 functions as an iron oxidase in neutrophilic iron-oxidizing organisms. The results of sequence analysis and modeling reveal that the entire Cyc2 family shares a unique fused cytochrome-porin structure, with a defining consensus motif in the cytochrome region. On the basis of results from structural analyses, we predict that the monoheme cytochrome Cyc2 specifically oxidizes dissolved Fe2+, in contrast to multiheme iron oxidases, which may oxidize solid Fe(II). With our results, there is now functional validation for diverse representatives of Cyc2 sequences. We present a comprehensive Cyc2 phylogenetic tree and offer a roadmap for identifying cyc2/Cyc2 homologs and interpreting their function. The occurrence of cyc2 in many genomes beyond known iron oxidizers presents the possibility that microbial iron oxidation may be a widespread metabolism.
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15
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Koeksoy E, Bezuidt OM, Bayer T, Chan CS, Emerson D. Zetaproteobacteria Pan-Genome Reveals Candidate Gene Cluster for Twisted Stalk Biosynthesis and Export. Front Microbiol 2021; 12:679409. [PMID: 34220764 PMCID: PMC8250860 DOI: 10.3389/fmicb.2021.679409] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 05/06/2021] [Indexed: 12/15/2022] Open
Abstract
Twisted stalks are morphologically unique bacterial extracellular organo-metallic structures containing Fe(III) oxyhydroxides that are produced by microaerophilic Fe(II)-oxidizers belonging to the Betaproteobacteria and Zetaproteobacteria. Understanding the underlying genetic and physiological mechanisms of stalk formation is of great interest based on their potential as novel biogenic nanomaterials and their relevance as putative biomarkers for microbial Fe(II) oxidation on ancient Earth. Despite the recognition of these special biominerals for over 150 years, the genetic foundation for the stalk phenotype has remained unresolved. Here we present a candidate gene cluster for the biosynthesis and secretion of the stalk organic matrix that we identified with a trait-based analyses of a pan-genome comprising 16 Zetaproteobacteria isolate genomes. The “stalk formation in Zetaproteobacteria” (sfz) cluster comprises six genes (sfz1-sfz6), of which sfz1 and sfz2 were predicted with functions in exopolysaccharide synthesis, regulation, and export, sfz4 and sfz6 with functions in cell wall synthesis manipulation and carbohydrate hydrolysis, and sfz3 and sfz5 with unknown functions. The stalk-forming Betaproteobacteria Ferriphaselus R-1 and OYT-1, as well as dread-forming Zetaproteobacteria Mariprofundus aestuarium CP-5 and Mariprofundus ferrinatatus CP-8 contain distant sfz gene homologs, whereas stalk-less Zetaproteobacteria and Betaproteobacteria lack the entire gene cluster. Our pan-genome analysis further revealed a significant enrichment of clusters of orthologous groups (COGs) across all Zetaproteobacteria isolate genomes that are associated with the regulation of a switch between sessile and motile growth controlled by the intracellular signaling molecule c-di-GMP. Potential interactions between stalk-former unique transcription factor genes, sfz genes, and c-di-GMP point toward a c-di-GMP regulated surface attachment function of stalks during sessile growth.
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Affiliation(s)
- Elif Koeksoy
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, United States.,Leibniz Institute DSMZ (German Collection of Microorganisms and Cell Cultures), Braunschweig, Germany
| | - Oliver M Bezuidt
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, United States
| | - Timm Bayer
- Geomicrobiology Group, Center for Applied Geoscience, University of Tübingen, Tübingen, Germany
| | - Clara S Chan
- Department of Earth Sciences, University of Delaware, Newark, DE, United States.,School of Marine Sciences and Policy, University of Delaware, Newark, DE, United States
| | - David Emerson
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, United States
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16
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Zeng X, Alain K, Shao Z. Microorganisms from deep-sea hydrothermal vents. MARINE LIFE SCIENCE & TECHNOLOGY 2021; 3:204-230. [PMID: 37073341 PMCID: PMC10077256 DOI: 10.1007/s42995-020-00086-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 11/17/2020] [Indexed: 05/03/2023]
Abstract
With a rich variety of chemical energy sources and steep physical and chemical gradients, hydrothermal vent systems offer a range of habitats to support microbial life. Cultivation-dependent and independent studies have led to an emerging view that diverse microorganisms in deep-sea hydrothermal vents live their chemolithoautotrophic, heterotrophic, or mixotrophic life with versatile metabolic strategies. Biogeochemical processes are mediated by microorganisms, and notably, processes involving or coupling the carbon, sulfur, hydrogen, nitrogen, and metal cycles in these unique ecosystems. Here, we review the taxonomic and physiological diversity of microbial prokaryotic life from cosmopolitan to endemic taxa and emphasize their significant roles in the biogeochemical processes in deep-sea hydrothermal vents. According to the physiology of the targeted taxa and their needs inferred from meta-omics data, the media for selective cultivation can be designed with a wide range of physicochemical conditions such as temperature, pH, hydrostatic pressure, electron donors and acceptors, carbon sources, nitrogen sources, and growth factors. The application of novel cultivation techniques with real-time monitoring of microbial diversity and metabolic substrates and products are also recommended. Supplementary Information The online version contains supplementary material available at 10.1007/s42995-020-00086-4.
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Affiliation(s)
- Xiang Zeng
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005 China
- LIA/IRP 1211 MicrobSea, Sino-French International Laboratory of Deep-Sea Microbiology, 29280 Plouzané, France
| | - Karine Alain
- Laboratoire de Microbiologie des Environnements Extrêmes LM2E UMR6197, Univ Brest, CNRS, IFREMER, F-29280 Plouzané, France
- LIA/IRP 1211 MicrobSea, Sino-French International Laboratory of Deep-Sea Microbiology, 29280 Plouzané, France
| | - Zongze Shao
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005 China
- LIA/IRP 1211 MicrobSea, Sino-French International Laboratory of Deep-Sea Microbiology, 29280 Plouzané, France
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17
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Cambon-Bonavita MA, Aubé J, Cueff-Gauchard V, Reveillaud J. Niche partitioning in the Rimicaris exoculata holobiont: the case of the first symbiotic Zetaproteobacteria. MICROBIOME 2021; 9:87. [PMID: 33845886 PMCID: PMC8042907 DOI: 10.1186/s40168-021-01045-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 03/09/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Free-living and symbiotic chemosynthetic microbial communities support primary production and higher trophic levels in deep-sea hydrothermal vents. The shrimp Rimicaris exoculata, which dominates animal communities along the Mid-Atlantic Ridge, houses a complex bacterial community in its enlarged cephalothorax. The dominant bacteria present are from the taxonomic groups Campylobacteria, Desulfobulbia (formerly Deltaproteobacteria), Alphaproteobacteria, Gammaproteobacteria, and some recently discovered iron oxyhydroxide-coated Zetaproteobacteria. This epibiotic consortium uses iron, sulfide, methane, and hydrogen as energy sources. Here, we generated shotgun metagenomes from Rimicaris exoculata cephalothoracic epibiotic communities to reconstruct and investigate symbiotic genomes. We collected specimens from three geochemically contrasted vent fields, TAG, Rainbow, and Snake Pit, to unravel the specificity, variability, and adaptation of Rimicaris-microbe associations. RESULTS Our data enabled us to reconstruct 49 metagenome-assembled genomes (MAGs) from the TAG and Rainbow vent fields, including 16 with more than 90% completion and less than 5% contamination based on single copy core genes. These MAGs belonged to the dominant Campylobacteria, Desulfobulbia, Thiotrichaceae, and some novel candidate phyla radiation (CPR) lineages. In addition, most importantly, two MAGs in our collection were affiliated to Zetaproteobacteria and had no close relatives (average nucleotide identity ANI < 77% with the closest relative Ghiorsea bivora isolated from TAG, and 88% with each other), suggesting potential novel species. Genes for Calvin-Benson Bassham (CBB) carbon fixation, iron, and sulfur oxidation, as well as nitrate reduction, occurred in both MAGs. However, genes for hydrogen oxidation and multicopper oxidases occurred in one MAG only, suggesting shared and specific potential functions for these two novel Zetaproteobacteria symbiotic lineages. Overall, we observed highly similar symbionts co-existing in a single shrimp at both the basaltic TAG and ultramafic Rainbow vent sites. Nevertheless, further examination of the seeming functional redundancy among these epibionts revealed important differences. CONCLUSION These data highlight microniche partitioning in the Rimicaris holobiont and support recent studies showing that functional diversity enables multiple symbiont strains to coexist in animals colonizing hydrothermal vents. Video Abstract.
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Affiliation(s)
- Marie-Anne Cambon-Bonavita
- Univ Brest, CNRS, IFREMER, Laboratoire de Microbiologie des Environnements Extrêmes, 29280 Plouzané, France
| | - Johanne Aubé
- Univ Brest, CNRS, IFREMER, Laboratoire de Microbiologie des Environnements Extrêmes, 29280 Plouzané, France
| | - Valérie Cueff-Gauchard
- Univ Brest, CNRS, IFREMER, Laboratoire de Microbiologie des Environnements Extrêmes, 29280 Plouzané, France
| | - Julie Reveillaud
- Univ Brest, CNRS, IFREMER, Laboratoire de Microbiologie des Environnements Extrêmes, 29280 Plouzané, France
- MIVEGEC, Univ. Montpellier, INRAe, CNRS, IRD, Montpellier, France
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18
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Kappler A, Bryce C, Mansor M, Lueder U, Byrne JM, Swanner ED. An evolving view on biogeochemical cycling of iron. Nat Rev Microbiol 2021; 19:360-374. [PMID: 33526911 DOI: 10.1038/s41579-020-00502-7] [Citation(s) in RCA: 202] [Impact Index Per Article: 67.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/08/2020] [Indexed: 01/23/2023]
Abstract
Biogeochemical cycling of iron is crucial to many environmental processes, such as ocean productivity, carbon storage, greenhouse gas emissions and the fate of nutrients, toxic metals and metalloids. Knowledge of the underlying processes involved in iron cycling has accelerated in recent years along with appreciation of the complex network of biotic and abiotic reactions dictating the speciation, mobility and reactivity of iron in the environment. Recent studies have provided insights into novel processes in the biogeochemical iron cycle such as microbial ammonium oxidation and methane oxidation coupled to Fe(III) reduction. They have also revealed that processes in the biogeochemical iron cycle spatially overlap and may compete with each other, and that oxidation and reduction of iron occur cyclically or simultaneously in many environments. This Review discusses these advances with particular focus on their environmental consequences, including the formation of greenhouse gases and the fate of nutrients and contaminants.
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Affiliation(s)
- Andreas Kappler
- Geomicrobiology, Center for Applied Geosciences, University of Tübingen, Tübingen, Germany.
| | - Casey Bryce
- School of Earth Sciences, University of Bristol, Bristol, UK
| | - Muammar Mansor
- Geomicrobiology, Center for Applied Geosciences, University of Tübingen, Tübingen, Germany
| | - Ulf Lueder
- Geomicrobiology, Center for Applied Geosciences, University of Tübingen, Tübingen, Germany
| | - James M Byrne
- School of Earth Sciences, University of Bristol, Bristol, UK
| | - Elizabeth D Swanner
- Department of Geological and Atmospheric Sciences, Iowa State University, Ames, IA, USA
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19
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Aerobic and anaerobic iron oxidizers together drive denitrification and carbon cycling at marine iron-rich hydrothermal vents. ISME JOURNAL 2020; 15:1271-1286. [PMID: 33328652 PMCID: PMC8114936 DOI: 10.1038/s41396-020-00849-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 11/06/2020] [Accepted: 11/18/2020] [Indexed: 12/02/2022]
Abstract
In principle, iron oxidation can fuel significant primary productivity and nutrient cycling in dark environments such as the deep sea. However, we have an extremely limited understanding of the ecology of iron-based ecosystems, and thus the linkages between iron oxidation, carbon cycling, and nitrate reduction. Here we investigate iron microbial mats from hydrothermal vents at Lōʻihi Seamount, Hawaiʻi, using genome-resolved metagenomics and metatranscriptomics to reconstruct potential microbial roles and interactions. Our results show that the aerobic iron-oxidizing Zetaproteobacteria are the primary producers, concentrated at the oxic mat surface. Their fixed carbon supports heterotrophs deeper in the mat, notably the second most abundant organism, Candidatus Ferristratum sp. (uncultivated gen. nov.) from the uncharacterized DTB120 phylum. Candidatus Ferristratum sp., described using nine high-quality metagenome-assembled genomes with similar distributions of genes, expressed nitrate reduction genes narGH and the iron oxidation gene cyc2 in situ and in response to Fe(II) in a shipboard incubation, suggesting it is an anaerobic nitrate-reducing iron oxidizer. Candidatus Ferristratum sp. lacks a full denitrification pathway, relying on Zetaproteobacteria to remove intermediates like nitrite. Thus, at Lōʻihi, anaerobic iron oxidizers coexist with and are dependent on aerobic iron oxidizers. In total, our work shows how key community members work together to connect iron oxidation with carbon and nitrogen cycling, thus driving the biogeochemistry of exported fluids.
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20
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Bellec L, Cambon-Bonavita MA, Durand L, Aube J, Gayet N, Sandulli R, Brandily C, Zeppilli D. Microbial Communities of the Shallow-Water Hydrothermal Vent Near Naples, Italy, and Chemosynthetic Symbionts Associated With a Free-Living Marine Nematode. Front Microbiol 2020; 11:2023. [PMID: 32973733 PMCID: PMC7469538 DOI: 10.3389/fmicb.2020.02023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 07/30/2020] [Indexed: 11/17/2022] Open
Abstract
Shallow-water hydrothermal vents are widespread, especially in the Mediterranean Sea, owing to the active volcanism of the area. Apart free microbial communities’ investigations, few biological studies have been leaded yet. Investigations of microbial communities associated with Nematoda, an ecologically important group in sediments, can help to improve our overall understanding of these ecosystems. We used a multidisciplinary-approach, based on microscopic observations (scanning electron microscopy: SEM and Fluorescence In Situ Hybridization: FISH) coupled with a molecular diversity analysis using metabarcoding, based on the 16S rRNA gene (V3-V4 region), to characterize the bacterial community of a free-living marine nematode and its environment, the shallow hydrothermal vent near Naples (Italy). Observations of living bacteria in the intestine (FISH), molecular and phylogenetic analyses showed that this species of nematode harbors its own bacterial community, distinct from the surrounding sediment and water. Metabarcoding results revealed the specific microbiomes of the sediment from three sites of this hydrothermal area to be composed mainly of sulfur oxidizing and reducing related bacteria.
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Affiliation(s)
- Laure Bellec
- Ifremer, Centre Brest, REM/EEP/LEP, ZI de la Pointe du Diable, CS10070, Plouzané, France.,Laboratoire de Microbiologie des Environnements Extrêmes, Ifremer, CNRS, Univ Brest, Plouzané, France.,EPOC, UMR 5805, University of Bordeaux, Arcachon, France
| | | | - Lucile Durand
- Laboratoire de Microbiologie des Environnements Extrêmes, Ifremer, CNRS, Univ Brest, Plouzané, France
| | - Johanne Aube
- Laboratoire de Microbiologie des Environnements Extrêmes, Ifremer, CNRS, Univ Brest, Plouzané, France
| | - Nicolas Gayet
- Ifremer, Centre Brest, REM/EEP/LEP, ZI de la Pointe du Diable, CS10070, Plouzané, France
| | - Roberto Sandulli
- Laboratory of Marine Ecology, Department of Science and Technology, University of Naples "Parthenope," Naples, Italy
| | - Christophe Brandily
- Ifremer, Centre Brest, REM/EEP/LEP, ZI de la Pointe du Diable, CS10070, Plouzané, France
| | - Daniela Zeppilli
- Ifremer, Centre Brest, REM/EEP/LEP, ZI de la Pointe du Diable, CS10070, Plouzané, France
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21
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Genomic Insights into Two Novel Fe(II)-Oxidizing Zetaproteobacteria Isolates Reveal Lifestyle Adaption to Coastal Marine Sediments. Appl Environ Microbiol 2020; 86:AEM.01160-20. [PMID: 32561582 DOI: 10.1128/aem.01160-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 06/13/2020] [Indexed: 11/20/2022] Open
Abstract
The discovery of the novel Zetaproteobacteria class greatly expanded our understanding of neutrophilic, microaerophilic microbial Fe(II) oxidation in marine environments. Despite molecular techniques demonstrating their global distribution, relatively few isolates exist, especially from low-Fe(II) environments. Furthermore, the Fe(II) oxidation pathways used by Zetaproteobacteria remain poorly understood. Here, we present the genomes (>99% genome completeness) of two Zetaproteobacteria, which are the only cultivated isolates originating from typical low-Fe [porewater Fe(II), 70 to 100 μM] coastal marine sediments. The two strains share <90% average nucleotide identity (ANI) with each other and <80% ANI with any other Zetaproteobacteria genome. The closest relatives were Mariprofundus aestuarium strain CP-5 and Mariprofundus ferrinatatus strain CP-8 (96 to 98% 16S rRNA gene sequence similarity). Fe(II) oxidation of strains KV and NF is most likely mediated by the putative Fe(II) oxidase Cyc2. Interestingly, the genome of strain KV also encodes a putative multicopper oxidase, PcoAB, which could play a role in Fe(II) oxidation, a pathway found only in two other Zetaproteobacteria genomes (Ghiorsea bivora TAG-1 and SCGC AB-602-C20). The strains show potential adaptations to fluctuating O2 concentrations, indicated by the presence of both cbb 3- and aa 3-type cytochrome c oxidases, which are adapted to low and high O2 concentrations, respectively. This is further supported by the presence of several oxidative-stress-related genes. In summary, our results reveal the potential Fe(II) oxidation pathways employed by these two novel chemolithoautotrophic Fe(II)-oxidizing species and the lifestyle adaptations which enable the Zetaproteobacteria to survive in coastal environments with low Fe(II) and regular redox fluctuations.IMPORTANCE Until recently, the importance and relevance of Zetaproteobacteria were mainly thought to be restricted to high-Fe(II) environments, such as deep-sea hydrothermal vents. The two novel Mariprofundus isolates presented here originate from typical low-Fe(II) coastal marine sediments. As well as being low in Fe(II), these environments are often subjected to fluctuating O2 concentrations and regular mixing by wave action and bioturbation. The discovery of two novel isolates highlights the importance of these organisms in such environments, as Fe(II) oxidation has been shown to impact nutrients and trace metals. Genome analysis of these two strains further supported their lifestyle adaptation and therefore their potential preference for coastal marine sediments, as genes necessary for surviving dynamic O2 concentrations and oxidative stress were identified. Furthermore, our analyses also expand our understanding of the poorly understood Fe(II) oxidation pathways used by neutrophilic, microaerophilic Fe(II) oxidizers.
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McAllister SM, Polson SW, Butterfield DA, Glazer BT, Sylvan JB, Chan CS. Validating the Cyc2 Neutrophilic Iron Oxidation Pathway Using Meta-omics of Zetaproteobacteria Iron Mats at Marine Hydrothermal Vents. mSystems 2020; 5:e00553-19. [PMID: 32071158 PMCID: PMC7029218 DOI: 10.1128/msystems.00553-19] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 01/22/2020] [Indexed: 01/04/2023] Open
Abstract
Zetaproteobacteria create extensive iron (Fe) oxide mats at marine hydrothermal vents, making them an ideal model for microbial Fe oxidation at circumneutral pH. Comparison of neutrophilic Fe oxidizer isolate genomes has revealed a hypothetical Fe oxidation pathway, featuring a homolog of the Fe oxidase Cyc2 from Acidithiobacillus ferrooxidans However, Cyc2 function is not well verified in neutrophilic Fe oxidizers, particularly in Fe-oxidizing environments. Toward this, we analyzed genomes and metatranscriptomes of Zetaproteobacteria, using 53 new high-quality metagenome-assembled genomes reconstructed from Fe mats at Mid-Atlantic Ridge, Mariana Backarc, and Loihi Seamount (Hawaii) hydrothermal vents. Phylogenetic analysis demonstrated conservation of Cyc2 sequences among most neutrophilic Fe oxidizers, suggesting a common function. We confirmed the widespread distribution of cyc2 and other model Fe oxidation pathway genes across all represented Zetaproteobacteria lineages. High expression of these genes was observed in diverse Zetaproteobacteria under multiple environmental conditions and in incubations. The putative Fe oxidase gene cyc2 was highly expressed in situ, often as the top expressed gene. The cyc2 gene showed increased expression in Fe(II)-amended incubations, with corresponding increases in carbon fixation and central metabolism gene expression. These results substantiate the Cyc2-based Fe oxidation pathway in neutrophiles and demonstrate its significance in marine Fe-mineralizing environments.IMPORTANCE Iron oxides are important components of our soil, water supplies, and ecosystems, as they sequester nutrients, carbon, and metals. Microorganisms can form iron oxides, but it is unclear whether this is a significant mechanism in the environment. Unlike other major microbial energy metabolisms, there is no marker gene for iron oxidation, hindering our ability to track these microbes. Here, we investigate a promising possible iron oxidation gene, cyc2, in iron-rich hydrothermal vents, where iron-oxidizing microbes dominate. We pieced together diverse Zetaproteobacteria genomes, compared these genomes, and analyzed expression of cyc2 and other hypothetical iron oxidation genes. We show that cyc2 is widespread among iron oxidizers and is highly expressed and potentially regulated, making it a good marker for the capacity for iron oxidation and potentially a marker for activity. These findings will help us understand and potentially quantify the impacts of neutrophilic iron oxidizers in a wide variety of marine and terrestrial environments.
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Affiliation(s)
- Sean M McAllister
- School of Marine Science and Policy, University of Delaware, Newark, Delaware, USA
| | - Shawn W Polson
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, Delaware, USA
| | - David A Butterfield
- Joint Institute for the Study of Atmosphere and Ocean, University of Washington, Seattle, Washington, USA
- Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration, Seattle, Washington, USA
| | - Brian T Glazer
- Department of Oceanography, University of Hawai'i, Honolulu, Hawai'i, USA
| | - Jason B Sylvan
- Department of Oceanography, Texas A&M University, College Station, Texas, USA
| | - Clara S Chan
- School of Marine Science and Policy, University of Delaware, Newark, Delaware, USA
- Department of Earth Sciences, University of Delaware, Newark, Delaware, USA
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Ward LM, Idei A, Nakagawa M, Ueno Y, Fischer WW, McGlynn SE. Geochemical and Metagenomic Characterization of Jinata Onsen, a Proterozoic-Analog Hot Spring, Reveals Novel Microbial Diversity including Iron-Tolerant Phototrophs and Thermophilic Lithotrophs. Microbes Environ 2019; 34:278-292. [PMID: 31413226 PMCID: PMC6759342 DOI: 10.1264/jsme2.me19017] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Hydrothermal systems, including terrestrial hot springs, contain diverse geochemical conditions that vary over short spatial scales due to progressive interactions between reducing hydrothermal fluids, the oxygenated atmosphere, and, in some cases, seawater. At Jinata Onsen on Shikinejima Island, Japan, an intertidal, anoxic, iron-rich hot spring mixes with the oxygenated atmosphere and seawater over short spatial scales, creating diverse chemical potentials and redox pairs over a distance of ~10 m. We characterized geochemical conditions along the outflow of Jinata Onsen as well as the microbial communities present in biofilms, mats, and mineral crusts along its traverse using 16S rRNA gene amplicon and genome-resolved shotgun metagenomic sequencing. Microbial communities significantly changed downstream as temperatures and dissolved iron concentrations decreased and dissolved oxygen increased. Biomass was more limited near the spring source than downstream, and primary productivity appeared to be fueled by the oxidation of ferrous iron and molecular hydrogen by members of Zetaproteobacteria and Aquificae. The microbial community downstream was dominated by oxygenic Cyanobacteria. Cyanobacteria are abundant and active even at ferrous iron concentrations of ~150 μM, which challenges the idea that iron toxicity limited cyanobacterial expansion in Precambrian oceans. Several novel lineages of Bacteria are also present at Jinata Onsen, including previously uncharacterized members of the phyla Chloroflexi and Calditrichaeota, positioning Jinata Onsen as a valuable site for the future characterization of these clades.
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Affiliation(s)
- Lewis M Ward
- Department of Earth and Planetary Sciences, Harvard University.,Earth-Life Science Institute, Tokyo Institute of Technology.,Division of Geological and Planetary Sciences, California Institute of Technology
| | - Airi Idei
- Department of Biological Sciences, Tokyo Metropolitan University
| | | | - Yuichiro Ueno
- Earth-Life Science Institute, Tokyo Institute of Technology.,Department of Earth and Planetary Sciences, Tokyo Institute of Technology.,Department of Subsurface Geobiological Analysis and Research, Japan Agency for Marine-Earth Science and Technology
| | - Woodward W Fischer
- Division of Geological and Planetary Sciences, California Institute of Technology
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Environmental Evidence for and Genomic Insight into the Preference of Iron-Oxidizing Bacteria for More-Corrosion-Resistant Stainless Steel at Higher Salinities. Appl Environ Microbiol 2019; 85:AEM.00483-19. [PMID: 31076431 DOI: 10.1128/aem.00483-19] [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: 02/26/2019] [Accepted: 05/07/2019] [Indexed: 11/20/2022] Open
Abstract
Iron-oxidizing bacteria (FeOB) are some of the initial colonizing organisms during microbially influenced corrosion of steel infrastructure. To better understand the abiotic conditions under which FeOB colonize steel, an environmental study was conducted to determine the effects of salinity, temperature, dissolved oxygen levels, and steel type on FeOB colonization. Stainless steel (304 and 316 [i.e., 304SS and 316SS]) was used to determine the potential susceptibility of these specialized corrosion-resistant steels. Steel coupon deployments along salinity gradients in two river systems revealed attachment by FeOB at all sites, with greater abundance of FeOB at higher salinities and on 316SS, compared to 304SS. This may be due to the presence of molybdenum in 316SS, potentially providing a selective advantage for FeOB colonization. A novel Zetaproteobacteria species, Mariprofundus erugo, was isolated from these stainless steel samples. Genes for molybdenum utilization and uptake and reactive oxygen species protection were found within its genome, supporting the evidence from our FeOB abundance data; they may represent adaptations of FeOB for colonization of surfaces of anthropogenic iron sources such as stainless steel. These results reveal environmental conditions under which FeOB colonize steel surfaces most abundantly, and they provide the framework needed to develop biocorrosion prevention strategies for stainless steel infrastructure in coastal estuarine areas.IMPORTANCE Colonization of FeOB on corrosion-resistant stainless steel types (304SS and 316SS) has been quantified from environmental deployments along salinity gradients in estuarine environments. Greater FeOB abundance at higher salinities and on the more-corrosion-resistant 316SS suggests that there may be a higher risk of biocorrosion at higher salinities and there may be a selective advantage from certain stainless steel alloy metals, such as molybdenum, for FeOB colonization. A novel species of FeOB described here was isolated from our stainless steel coupon deployments, and its genome sequence supports our environmental data, as genes involved in the potential selectiveness toward surface colonization of stainless steel might lead to higher rates of biocorrosion of manmade aquatic infrastructure. These combined results provide environmental constraints for FeOB colonization on anthropogenic iron sources and build on previous frameworks for biocorrosion prevention strategies.
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25
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Greening C, Grinter R, Chiri E. Uncovering the Metabolic Strategies of the Dormant Microbial Majority: towards Integrative Approaches. mSystems 2019; 4:e00107-19. [PMID: 31120024 PMCID: PMC6529542 DOI: 10.1128/msystems.00107-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 03/11/2019] [Indexed: 11/20/2022] Open
Abstract
A grand challenge in microbiology is to understand how the dormant majority lives. In natural environments, most microorganisms are not growing and instead exist in a spectrum of dormant states. Despite this, most research on microbial metabolism continues to be growth-centric, and many overlook the fact that dormant cells require energy for maintenance. In this perspective, we discuss our research program to uncover the metabolic strategies that support microbial survival. We present two major principles underlying these studies. The first is the recent realization that microbial survival depends on previously unrecognized metabolic flexibility. The second is that new discoveries in this area depend on more sophisticated integration of approaches at the molecular, cellular, and ecosystem levels. These principles are illustrated with examples from the literature, including our own work demonstrating that bacteria can live on air, and areas for future methodological and theoretical development are highlighted.
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Affiliation(s)
- Chris Greening
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
| | - Rhys Grinter
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
| | - Eleonora Chiri
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
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26
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Gonnella G, Adam N, Perner M. Horizontal acquisition of hydrogen conversion ability and other habitat adaptations in the Hydrogenovibrio strains SP-41 and XCL-2. BMC Genomics 2019; 20:339. [PMID: 31060509 PMCID: PMC6501319 DOI: 10.1186/s12864-019-5710-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 04/17/2019] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Obligate sulfur oxidizing chemolithoauthotrophic strains of Hydrogenovibrio crunogenus have been isolated from multiple hydrothermal vent associated habitats. However, a hydrogenase gene cluster (encoding the hydrogen converting enzyme and its maturation/assembly machinery) detected on the first sequenced H. crunogenus strain (XCL-2) suggested that hydrogen conversion may also play a role in this organism. Yet, numerous experiments have underlined XCL-2's inability to consume hydrogen under the tested conditions. A recent study showed that the closely related strain SP-41 contains a homolog of the XCL-2 hydrogenase (a group 1b [NiFe]-hydrogenase), but that it can indeed use hydrogen. Hence, the question remained unresolved, why SP-41 is capable of using hydrogen, while XCL-2 is not. RESULTS Here, we present the genome sequence of the SP-41 strain and compare it to that of the XCL-2 strain. We show that the chromosome of SP-41 codes for a further hydrogenase gene cluster, including two additional hydrogenases: the first appears to be a group 1d periplasmic membrane-anchored hydrogenase, and the second a group 2b sensory hydrogenase. The region where these genes are located was likely acquired horizontally and exhibits similarity to other Hydrogenovibrio species (H. thermophilus MA2-6 and H. marinus MH-110 T) and other hydrogen oxidizing Proteobacteria (Cupriavidus necator H16 and Ghiorsea bivora TAG-1 T). The genomes of XCL-2 and SP-41 show a strong conservation in gene order. However, several short genomic regions are not contained in the genome of the other strain. These exclusive regions are often associated with signs of DNA mobility, such as genes coding for transposases. They code for transport systems and/or extend the metabolic potential of the strains. CONCLUSIONS Our results suggest that horizontal gene transfer plays an important role in shaping the genomes of these strains, as a likely mechanism for habitat adaptation, including, but not limited to the transfer of the hydrogen conversion ability.
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Affiliation(s)
- Giorgio Gonnella
- Universität Hamburg, MIN-Fakultät, ZBH - Center for Bioinformatics, Bundesstraße 43, Hamburg, 20146 Germany
| | - Nicole Adam
- GEOMAR Helmholtz Center for Ocean Research Kiel, Geomicrobiology, Wischhofstr. 1-3, Kiel, 24148 Germany
- previous address: Universität Hamburg, MIN-Fakultät, Biocenter Klein Flottbek, Molecular Biology of Microbial Consortia, Ohnhorststr. 18, Hamburg, 22609 Germany
| | - Mirjam Perner
- GEOMAR Helmholtz Center for Ocean Research Kiel, Geomicrobiology, Wischhofstr. 1-3, Kiel, 24148 Germany
- previous address: Universität Hamburg, MIN-Fakultät, Biocenter Klein Flottbek, Molecular Biology of Microbial Consortia, Ohnhorststr. 18, Hamburg, 22609 Germany
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27
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Campen R, Kowalski J, Lyons WB, Tulaczyk S, Dachwald B, Pettit E, Welch KA, Mikucki JA. Microbial diversity of an Antarctic subglacial community and high-resolution replicate sampling inform hydrological connectivity in a polar desert. Environ Microbiol 2019; 21:2290-2306. [PMID: 30927377 DOI: 10.1111/1462-2920.14607] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 03/22/2019] [Accepted: 03/23/2019] [Indexed: 11/30/2022]
Abstract
Antarctic subglacial environments host microbial ecosystems and are proving to be geochemically and biologically diverse. The Taylor Glacier, Antarctica, periodically expels iron-rich brine through a conduit sourced from a deep subglacial aquifer, creating a dramatic red surface feature known as Blood Falls. We used Illumina MiSeq sequencing to describe the core microbiome of this subglacial brine and identified previously undetected but abundant groups including the candidate bacterial phylum Atribacteria and archaeal phylum Pacearchaeota. Our work represents the first microbial characterization of samples collected from within a glacier using a melt probe, and the only Antarctic subglacial aquatic environment that, to date, has been sampled twice. A comparative analysis showed the brine community to be stable at the operational taxonomic unit level of 99% identity over a decade. Higher resolution sequencing enabled deconvolution of the microbiome of subglacial brine from mixtures of materials collected at the glacier surface. Diversity patterns between this brine and samples from the surrounding landscape provide insight into the hydrological connectivity of subglacial fluids to the surface polar desert environment. Understanding subice brines collected on the surfaces of thick ice covers has implications for analyses of expelled materials that may be sampled on icy extraterrestrial worlds.
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Affiliation(s)
- Richard Campen
- Department of Microbiology, University of Tennessee, Knoxville, TN, 37996, USA
| | | | | | - Slawek Tulaczyk
- University of California, Santa Cruz, Santa Cruz, CA, 95064, USA
| | - Bernd Dachwald
- Faculty of Aerospace Engineering, FH Aachen University of Applied Sciences, Aachen, Germany
| | - Erin Pettit
- College of Earth, Ocean, and Atmospheric Science, Oregon State University, Corvallis, OR, 97331, USA
| | | | - Jill A Mikucki
- Department of Microbiology, University of Tennessee, Knoxville, TN, 37996, USA
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28
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McAllister SM, Moore RM, Gartman A, Luther GW, Emerson D, Chan CS. The Fe(II)-oxidizing Zetaproteobacteria: historical, ecological and genomic perspectives. FEMS Microbiol Ecol 2019; 95:fiz015. [PMID: 30715272 PMCID: PMC6443915 DOI: 10.1093/femsec/fiz015] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 01/29/2019] [Indexed: 01/22/2023] Open
Abstract
The Zetaproteobacteria are a class of bacteria typically associated with marine Fe(II)-oxidizing environments. First discovered in the hydrothermal vents at Loihi Seamount, Hawaii, they have become model organisms for marine microbial Fe(II) oxidation. In addition to deep sea and shallow hydrothermal vents, Zetaproteobacteria are found in coastal sediments, other marine subsurface environments, steel corrosion biofilms and saline terrestrial springs. Isolates from a range of environments all grow by autotrophic Fe(II) oxidation. Their success lies partly in their microaerophily, which enables them to compete with abiotic Fe(II) oxidation at Fe(II)-rich oxic/anoxic transition zones. To determine the known diversity of the Zetaproteobacteria, we have used 16S rRNA gene sequences to define 59 operational taxonomic units (OTUs), at 97% similarity. While some Zetaproteobacteria taxa appear to be cosmopolitan, others are enriched by specific habitats. OTU networks show that certain Zetaproteobacteria co-exist, sharing compatible niches. These niches may correspond with adaptations to O2, H2 and nitrate availability, based on genomic analyses of metabolic potential. Also, a putative Fe(II) oxidation gene has been found in diverse Zetaproteobacteria taxa, suggesting that the Zetaproteobacteria evolved as Fe(II) oxidation specialists. In all, studies suggest that Zetaproteobacteria are widespread, and therefore may have a broad influence on marine and saline terrestrial Fe cycling.
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Affiliation(s)
- Sean M McAllister
- School of Marine Science and Policy, University of Delaware, 700 Pilottown Road, 204 Cannon Lab, Lewes, Delaware, USA 19958
| | - Ryan M Moore
- Center for Bioinformatics and Computational Biology, University of Delaware, 15 Innovation Way, 205 Delaware Biotechnology Institute, Newark, Delaware, USA 19711
| | - Amy Gartman
- School of Marine Science and Policy, University of Delaware, 700 Pilottown Road, 204 Cannon Lab, Lewes, Delaware, USA 19958
| | - George W Luther
- School of Marine Science and Policy, University of Delaware, 700 Pilottown Road, 204 Cannon Lab, Lewes, Delaware, USA 19958
| | - David Emerson
- Bigelow Laboratory for Ocean Sciences, 60 Bigelow Drive, East Boothbay, Maine, USA 04544
| | - Clara S Chan
- School of Marine Science and Policy, University of Delaware, 700 Pilottown Road, 204 Cannon Lab, Lewes, Delaware, USA 19958
- Department of Geological Sciences, University of Delaware, 101 Penny Hall, Newark, Delaware, USA 19716
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29
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Vander Roost J, Daae FL, Steen IH, Thorseth IH, Dahle H. Distribution Patterns of Iron-Oxidizing Zeta- and Beta-Proteobacteria From Different Environmental Settings at the Jan Mayen Vent Fields. Front Microbiol 2018; 9:3008. [PMID: 30574135 PMCID: PMC6292416 DOI: 10.3389/fmicb.2018.03008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 11/20/2018] [Indexed: 12/26/2022] Open
Abstract
Iron oxidizers are widespread in marine environments and play an important role in marine iron cycling. However, little is known about the overall distribution of iron oxidizers within hydrothermal systems, including settings with little hydrothermal activity. Moreover, the extent to which different phylogenetic groups of iron oxidizers exhibit niche specialization toward different environmental settings, remains largely unknown. Obtaining such knowledge is critical to unraveling the impact of the activity of iron oxidizers and how they are adapted. Here, we used 16S rRNA sequencing to characterize the distribution of iron oxidizers in different environmental settings within the Jan Mayen hydrothermal vent fields (JMVFs). Putative iron oxidizers affiliated to Zetaproteobacteria and Betaproteobacteria were detected within iron mounds, bottom seawater, basalt surfaces, and surface layers of sediments. The detected iron oxidizers were compared to sequence types previously observed in patchily distributed iron mats associated with diffuse venting at the JMVFs. Most OTUs of iron oxidizers reoccurred under different environmental settings, suggesting a limited degree of niche specialization. Consequently, most of the detected iron oxidizers seem to be generalists with a large habitat range. Our study highlights the importance of gathering information about the overall distribution of iron oxidizers in hydrothermal systems to fully understand the role of this metabolic group regarding cycling of iron. Furthermore, our results provide further evidence of the presence of iron-oxidizing members of Betaproteobacteria in marine environments.
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Affiliation(s)
- Jan Vander Roost
- Centre for Geobiology, University of Bergen, Bergen, Norway.,Department of Biology, University of Bergen, Bergen, Norway
| | - Frida Lise Daae
- Centre for Geobiology, University of Bergen, Bergen, Norway.,Department of Biology, University of Bergen, Bergen, Norway
| | - Ida Helene Steen
- Centre for Geobiology, University of Bergen, Bergen, Norway.,Department of Biology, University of Bergen, Bergen, Norway
| | - Ingunn Hindeness Thorseth
- Centre for Geobiology, University of Bergen, Bergen, Norway.,Department of Earth Science, University of Bergen, Bergen, Norway
| | - Håkon Dahle
- Centre for Geobiology, University of Bergen, Bergen, Norway.,Department of Biology, University of Bergen, Bergen, Norway
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30
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Emerson D. The role of iron-oxidizing bacteria in biocorrosion: a review. BIOFOULING 2018; 34:989-1000. [PMID: 30642207 DOI: 10.1080/08927014.2018.1526281] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 09/13/2018] [Accepted: 09/13/2018] [Indexed: 06/09/2023]
Abstract
Lithotrophic iron-oxidizing bacteria depend on reduced iron, Fe(II), as their primary energy source, making them natural candidates for growing in association with steel infrastructure and potentially contributing to microbially influenced corrosion (MIC). This review summarizes recent work on the role of iron-oxidizing bacteria (FeOB) in MIC. By virtue of producing complex 3-dimensional biofilms that result from the accumulation of iron-oxides, FeOB may aid in the colonization of steel surfaces by other microbes involved in MIC. Evidence points to a successional pattern occurring whereby FeOB are early colonizers of mild steel (MS), followed by sulfate-reducing bacteria and other microbes, although studies of aged corrosion products indicate that FeOB do establish a long-term presence. There is evidence that only specific clades of FeOB, with unique adaptations for growing on steel surfaces are part of the MIC community. These are discussed in the context of the larger MIC microbiome.
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Affiliation(s)
- David Emerson
- a Bigelow Laboratory for Ocean Sciences , East Boothbay , ME , USA
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31
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Otte JM, Harter J, Laufer K, Blackwell N, Straub D, Kappler A, Kleindienst S. The distribution of active iron‐cycling bacteria in marine and freshwater sediments is decoupled from geochemical gradients. Environ Microbiol 2018; 20:2483-2499. [DOI: 10.1111/1462-2920.14260] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 04/26/2018] [Accepted: 04/26/2018] [Indexed: 11/30/2022]
Affiliation(s)
- Julia M. Otte
- Geomicrobiology, Center for Applied Geosciences, University of Tübingen Germany
| | - Johannes Harter
- Geomicrobiology, Center for Applied Geosciences, University of Tübingen Germany
| | - Katja Laufer
- Geomicrobiology, Center for Applied Geosciences, University of Tübingen Germany
- Center for Geomicrobiology, Department of BioscienceAarhus University Denmark
| | - Nia Blackwell
- Microbial Ecology, Center for Applied GeosciencesUniversity of Tübingen Germany
| | - Daniel Straub
- Microbial Ecology, Center for Applied GeosciencesUniversity of Tübingen Germany
| | - Andreas Kappler
- Geomicrobiology, Center for Applied Geosciences, University of Tübingen Germany
- Center for Geomicrobiology, Department of BioscienceAarhus University Denmark
| | - Sara Kleindienst
- Microbial Ecology, Center for Applied GeosciencesUniversity of Tübingen Germany
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32
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Iron-oxidizing bacteria in marine environments: recent progresses and future directions. World J Microbiol Biotechnol 2018; 34:110. [PMID: 29974320 DOI: 10.1007/s11274-018-2491-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 06/26/2018] [Indexed: 10/28/2022]
Abstract
Iron-oxidizing bacteria (FeOB) refers to a group of bacteria with the ability to exchange and accumulate divalent iron dissolved in water as trivalent iron inside and outside the bacterial cell. Most FeOB belong the largest bacterial phylum, Proteobacteria. Within this phylum, FeOB with varying physiology with regards to their response to oxygen (obligate aerobes, facultative and obligate anaerobes) and pH optimum for proliferation (neutrophiles, moderate and extreme acidophiles) can be found. Although FeOB have been reported from a wide variety of environments, most of them have not been isolated and their biochemical characteristics remain largely unknown. This is especially true for those living in the marine realm, where the properties of FeOB was not known until the isolation of the Zetaproteobacteria Mariprofundus ferrooxydans, first reported in 2007. Since the proposal of Zetaproteobacteria by Emerson et al., the detection and isolation of those microorganisms from the marine environment has greatly escalated. Furthermore, FeOB have also recently been reported from works on ocean drilling and metal corrosion. This review aims to summarize the current state of phylogenetic and physiological diversity in marine FeOB, the significance of their roles in their environments (on both global and local scales), as well as their growing importance and applications in the industry.
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33
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Beam JP, Scott JJ, McAllister SM, Chan CS, McManus J, Meysman FJR, Emerson D. Biological rejuvenation of iron oxides in bioturbated marine sediments. ISME JOURNAL 2018; 12:1389-1394. [PMID: 29343830 DOI: 10.1038/s41396-017-0032-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 11/22/2017] [Accepted: 11/29/2017] [Indexed: 02/04/2023]
Abstract
The biogeochemical cycle of iron is intricately linked to numerous element cycles. Although biological processes that catalyze the reductive side of the iron cycle are established, little is known about microbial oxidative processes on iron cycling in sedimentary environments-resulting in the formation of iron oxides. Here we show that a potential source of sedimentary iron oxides originates from the metabolic activity of iron-oxidizing bacteria from the class Zetaproteobacteria, presumably enhanced by burrowing animals in coastal sediments. Zetaproteobacteria were estimated to be a global total of 1026 cells in coastal, bioturbated sediments, and predicted to annually produce 8 × 1015 g of Fe in sedimentary iron oxides-55 times larger than the annual flux of iron oxides deposited by rivers. These data suggest that iron-oxidizing Zetaproteobacteria are keystone organisms in marine sedimentary environments-despite their low numerical abundance-yet exert a disproportionate impact via the rejuvenation of iron oxides.
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Affiliation(s)
- Jacob P Beam
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, 04544, USA.
| | - Jarrod J Scott
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, 04544, USA.,Smithsonian Tropical Research Institute, Apartado Postal 0843-03092, Panamá, Republic of Panama
| | - Sean M McAllister
- Department of Geological Sciences, University of Delaware, Newark, DE, 19716, USA
| | - Clara S Chan
- Department of Geological Sciences, University of Delaware, Newark, DE, 19716, USA
| | - James McManus
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, 04544, USA
| | - Filip J R Meysman
- Department of Biology, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium.,Department of Biotechnology, Technical University of Delft, Van der Maasweg 9, 2629 HZ, Delft, The Netherlands
| | - David Emerson
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, 04544, USA
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Chiu BK, Kato S, McAllister SM, Field EK, Chan CS. Novel Pelagic Iron-Oxidizing Zetaproteobacteria from the Chesapeake Bay Oxic-Anoxic Transition Zone. Front Microbiol 2017; 8:1280. [PMID: 28769885 PMCID: PMC5513912 DOI: 10.3389/fmicb.2017.01280] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 06/26/2017] [Indexed: 01/11/2023] Open
Abstract
Chemolithotrophic iron-oxidizing bacteria (FeOB) could theoretically inhabit any environment where Fe(II) and O2 (or nitrate) coexist. Until recently, marine Fe-oxidizing Zetaproteobacteria had primarily been observed in benthic and subsurface settings, but not redox-stratified water columns. This may be due to the challenges that a pelagic lifestyle would pose for Zetaproteobacteria, given low Fe(II) concentrations in modern marine waters and the possibility that Fe oxyhydroxide biominerals could cause cells to sink. However, we recently cultivated Zetaproteobacteria from the Chesapeake Bay oxic–anoxic transition zone, suggesting that they can survive and contribute to biogeochemical cycling in a stratified estuary. Here we describe the isolation, characterization, and genomes of two new species, Mariprofundus aestuarium CP-5 and Mariprofundus ferrinatatus CP-8, which are the first Zetaproteobacteria isolates from a pelagic environment. We looked for adaptations enabling strains CP-5 and CP-8 to overcome the challenges of living in a low Fe redoxcline with frequent O2 fluctuations due to tidal mixing. We found that the CP strains produce distinctive dreadlock-like Fe oxyhydroxide structures that are easily shed, which would help cells maintain suspension in the water column. These oxides are by-products of Fe(II) oxidation, likely catalyzed by the putative Fe(II) oxidase encoded by the cyc2 gene, present in both CP-5 and CP-8 genomes; the consistent presence of cyc2 in all microaerophilic FeOB and other FeOB genomes supports its putative role in Fe(II) oxidation. The CP strains also have two gene clusters associated with biofilm formation (Wsp system and the Widespread Colonization Island) that are absent or rare in other Zetaproteobacteria. We propose that biofilm formation enables the CP strains to attach to FeS particles and form flocs, an advantageous strategy for scavenging Fe(II) and developing low [O2] microenvironments within more oxygenated waters. However, the CP strains appear to be adapted to somewhat higher concentrations of O2, as indicated by the presence of genes encoding aa3-type cytochrome c oxidases, but not the cbb3-type found in all other Zetaproteobacteria isolate genomes. Overall, our results reveal adaptations for life in a physically dynamic, low Fe(II) water column, suggesting that niche-specific strategies can enable Zetaproteobacteria to live in any environment with Fe(II).
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Affiliation(s)
- Beverly K Chiu
- Department of Geological Sciences, University of Delaware, NewarkDE, United States
| | - Shingo Kato
- Project Team for Development of New-Generation Research Protocol for Submarine Resources, Japan Agency for Marine-Earth Science and TechnologyKanagawa, Japan
| | - Sean M McAllister
- School of Marine Science and Policy, University of Delaware, NewarkDE, United States
| | - Erin K Field
- Department of Biology, East Carolina University, GreenvilleNC, United States
| | - Clara S Chan
- Department of Geological Sciences, University of Delaware, NewarkDE, United States.,School of Marine Science and Policy, University of Delaware, NewarkDE, United States
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