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Popall RM, Postec A, Lecoeuvre A, Quéméneur M, Erauso G. Metabolic challenges and key players in serpentinite-hosted microbial ecosystems. Front Microbiol 2023; 14:1197823. [PMID: 37555067 PMCID: PMC10404738 DOI: 10.3389/fmicb.2023.1197823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 06/29/2023] [Indexed: 08/10/2023] Open
Abstract
Serpentinite-hosted systems are amongst the most challenging environments for life on Earth. Serpentinization, a geochemical alteration of exposed ultramafic rock, produces hydrothermal fluids enriched in abiotically derived hydrogen (H2), methane (CH4), and small organic molecules. The hyperalkaline pH of these fluids poses a great challenge for metabolic energy and nutrient acquisition, curbing the cellular membrane potential and limiting electron acceptor, carbon, and phosphorous availability. Nevertheless, serpentinization supports the growth of diverse microbial communities whose metabolic make-up might shed light on the beginning of life on Earth and potentially elsewhere. Here, we outline current hypotheses on metabolic energy production, carbon fixation, and nutrient acquisition in serpentinizing environments. A taxonomic survey is performed for each important metabolic function, highlighting potential key players such as H2 and CH4 cycling Serpentinimonas, Hydrogenophaga, Methanobacteriales, Methanosarcinales, and novel candidate phyla. Methodological biases of the available data and future approaches are discussed.
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Affiliation(s)
| | | | | | | | - Gaël Erauso
- Aix-Marseille Univ, Univ Toulon, CNRS, IRD, MIO, Marseille, France
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Quéméneur M, Mei N, Monnin C, Postec A, Guasco S, Jeanpert J, Maurizot P, Pelletier B, Erauso G. Microbial taxa related to natural hydrogen and methane emissions in serpentinite-hosted hyperalkaline springs of New Caledonia. Front Microbiol 2023; 14:1196516. [PMID: 37485525 PMCID: PMC10359428 DOI: 10.3389/fmicb.2023.1196516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 06/20/2023] [Indexed: 07/25/2023] Open
Abstract
The southeastern part of New Caledonia main island (Grande Terre) is the location of a large ophiolitic formation that hosts several hyperalkaline springs discharging high pH (∼11) and warm (<40°C) fluids enriched in methane (CH4) and hydrogen (H2). These waters are produced by the serpentinization of the ultrabasic rock formations. Molecular surveys had previously revealed the prokaryotic diversity of some of these New Caledonian springs, especially from the submarine chimneys of Prony Bay hydrothermal field. Here we investigate the microbial community of hyperalkaline waters from on-land springs and their relationships with elevated concentrations of dissolved H2 (21.1-721.3 μmol/L) and CH4 (153.0-376.6 μmol/L). 16S rRNA gene analyses (metabarcoding and qPCR) provided evidence of abundant and diverse prokaryotic communities inhabiting hyperalkaline fluids at all the collected springs. The abundance of prokaryotes was positively correlated to the H2/CH4 ratio. Prokaryotes consisted mainly of bacteria that use H2 as an energy source, such as microaerophilic Hydrogenophaga/Serpentinimonas (detected in all sources on land) or anaerobic sulfate-reducing Desulfonatronum, which were exclusively found in the most reducing (Eh ref H2 ∼ -700 mV) and the most H2-enriched waters discharging at the intertidal spring of the Bain des Japonais. The relative abundance of a specific group of uncultured Methanosarcinales that thrive in serpentinization-driven ecosystems emitting H2, considered potential H2-consuming methanogens, was positively correlated with CH4 concentrations, and negatively correlated to the relative abundance of methylotrophic Gammaproteobacteria. Firmicutes were also numerous in hyperalkaline waters, and their relative abundance (e.g., Gracilibacter or Dethiobacter) was proportional to the dissolved H2 concentrations, but their role in the H2 budget remains to be assessed. The prokaryotic communities thriving in New Caledonia hyperalkaline waters are similar to those found in other serpentinite-hosted high-pH waters worldwide, such as Lost City (North Atlantic) and The Cedars (California).
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Affiliation(s)
- Marianne Quéméneur
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO, Marseille, France
| | - Nan Mei
- School of Chemistry, Chemical Engineering, and Life Science, Wuhan University of Technology, Wuhan, China
| | - Christophe Monnin
- Géosciences Environnement Toulouse, UMR 5563 (CNRS/UPS/IRD/CNES), Toulouse, France
| | - Anne Postec
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO, Marseille, France
| | - Sophie Guasco
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO, Marseille, France
| | - Julie Jeanpert
- Direction de l’Industrie, des Mines et de l’Energie, Nouméa, New Caledonia
| | - Pierre Maurizot
- Direction de l’Industrie, des Mines et de l’Energie, Nouméa, New Caledonia
| | | | - Gaël Erauso
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO, Marseille, France
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Řezanka T, Kyselová L, Murphy DJ. Archaeal lipids. Prog Lipid Res 2023; 91:101237. [PMID: 37236370 DOI: 10.1016/j.plipres.2023.101237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 04/25/2023] [Accepted: 05/19/2023] [Indexed: 05/28/2023]
Abstract
The major archaeal membrane glycerolipids are distinguished from those of bacteria and eukaryotes by the contrasting stereochemistry of their glycerol backbones, and by the use of ether-linked isoprenoid-based alkyl chains rather than ester-linked fatty acyl chains for their hydrophobic moieties. These fascinating compounds play important roles in the extremophile lifestyles of many species, but are also present in the growing numbers of recently discovered mesophilic archaea. The past decade has witnessed significant advances in our understanding of archaea in general and their lipids in particular. Much of the new information has come from the ability to screen large microbial populations via environmental metagenomics, which has revolutionised our understanding of the extent of archaeal biodiversity that is coupled with a strict conservation of their membrane lipid compositions. Significant additional progress has come from new culturing and analytical techniques that are gradually enabling archaeal physiology and biochemistry to be studied in real time. These studies are beginning to shed light on the much-discussed and still-controversial process of eukaryogenesis, which probably involved both bacterial and archaeal progenitors. Puzzlingly, although eukaryotes retain many attributes of their putative archaeal ancestors, their lipid compositions only reflect their bacterial progenitors. Finally, elucidation of archaeal lipids and their metabolic pathways have revealed potentially interesting applications that have opened up new frontiers for biotechnological exploitation of these organisms. This review is concerned with the analysis, structure, function, evolution and biotechnology of archaeal lipids and their associated metabolic pathways.
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Affiliation(s)
- Tomáš Řezanka
- Institute of Microbiology, Czech Academy of Sciences, Vídeňská 1083, 142 00 Prague, Czech Republic
| | - Lucie Kyselová
- Research Institute of Brewing and Malting, Lípová 511, 120 44 Prague, Czech Republic
| | - Denis J Murphy
- School of Applied Sciences, University of South Wales, Pontypridd, CF37 1DL, United Kingdom.
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Mei N, Postec A, Bartoli M, Vandecasteele C, Wils L, Gil L, Monnin C, Pelletier B, Erauso G, Quéméneur M. Methanobacterium alkalithermotolerans sp. nov., a novel alkaliphilic and hydrogen-utilizing methanogen isolated from an alkaline geothermal spring (La Crouen, New Caledonia). Int J Syst Evol Microbiol 2022; 72. [PMID: 36260502 DOI: 10.1099/ijsem.0.005554] [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] [Indexed: 06/16/2023] Open
Abstract
An anaerobic, hydrogenotrophic methane-producing archaeon was isolated from an alkaline thermal spring (42 °C, pH 9.0) in New Caledonia. This methanogen, designated strain CANT, is alkaliphilic, thermotolerant, with Gram-positive staining non-motile cells. Strain CANT grows autotrophically using hydrogen exclusively as an energy source and carbon dioxide as the sole carbon source (without the requirement of yeast extract or other organic compounds). It grows at 20-45 °C (optimum, 45 °C) and pH 7.3-9.7 (optimum, pH 9.0). NaCl is not required for growth (optimum 0 %) but is tolerated up to 1.5 %. It resists novobiocin, streptomycin and vancomycin but is inhibited by ampicillin and penicillin, among other antibiotics. The genome consists of a circular chromosome (2.2 Mb) containing 2126 predicted protein-encoding genes with a G+C content of 36.4 mol%. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain CANT is a member of the genus Methanobacterium, most closely related to the alkaliphilic Methanobacterium alcaliphilum WeN4T with 98.5 % 16S rRNA gene sequence identity. The genomes of strain CANT and M. alcaliphilum DSM 3459, sequenced in this study, share 71.6 % average nucleotide identity and 14.0 % digital DNA-DNA hybridization. Therefore, phylogenetic and physiological results indicate that strain CANT represents a novel species, for which the name Methanobacterium alkalithermotolerans sp. nov. is proposed, and strain CANT (=DSM 102889T= JCM 31304T) is assigned as the type strain.
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Affiliation(s)
- Nan Mei
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO, Marseille, France
- Present address: School of Chemistry, Chemical Engineering, and Life Science, Wuhan University of Technology, Wuhan 430070, PR China
| | - Anne Postec
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO, Marseille, France
| | - Manon Bartoli
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO, Marseille, France
| | | | - Laura Wils
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO, Marseille, France
| | - Lisa Gil
- INRAE, US 1426, GeT-PlaGe, Genotoul, Castanet-Tolosan, France
| | - Christophe Monnin
- GET UMR5563 (CNRS/UPS/IRD/CNES), Géosciences Environnement Toulouse, 14 Avenue Edouard Belin, 31400 Toulouse, France
| | - Bernard Pelletier
- UMR Géoazur, Centre IRD de Nouméa, 101 Promenade Roger Laroque, BP A5 - 98848 Nouméa cedex, New Caledonia
| | - Gael Erauso
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO, Marseille, France
| | - Marianne Quéméneur
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO, Marseille, France
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