An Anaerobic Microbial Community Mediates Epigenetic Native Sulfur and Carbonate Formation During Replacement of Messinian Gypsum at Monte Palco, Sicily

Geobiology, Год журнала: 2025, Номер 23(2)

Опубликована: Март 1, 2025

The microbially mediated replacement of sulfate-bearing evaporites by authigenic carbonate and native sulfur under anoxic conditions is poorly understood. Sulfur-bearing carbonates from the Monte Palco ridge (Sicily) replacing Messinian gypsum were therefore studied to better characterize involved microorganisms. lack (1) sedimentary bedding, (2) lamination, (3) significant water-column-derived lipid biomarkers in secondary implies after deposition (epigenesis). Allochthonous clasts older Calcare di Base younger Trubi Formation within these further evidence epigenetic formation. sulfur-bearing are significantly 13C-depleted (δ13C as low -51‰), identifying methane a major carbon source. 18O-enrichment (δ18O high 5.4‰) probably reflects precipitation 18O-enriched fluids transported along adjacent faults or closed system with very little water. Native variable 34S-enrichment (δ34S 18.9‰), relatively small maximum offset (12.3‰) between sulfate source (gypsum) sulfur, δ34S values carbonate-associated (as 61.1‰) suggest conversion (semi-)closed system, insignificant removal. Anaerobic methanotrophic archaea (ANME) apparently affiliated ANME-1 clade mineral formation evidenced biomarker inventory, which contains abundant isoprenoids including sn3-hydroxyarchaeol sole hydroxyarchaeol isomer glycerol dibiphytanyl tetraethers (GDGTs). A series various, tentatively identified non-isoprenoidal dialkyl diethers (DAGEs), 10me-C16 fatty acid, hydroxy C16 acids, cyclopropyl-C17:0ω7,8 acid agree sulfate-reducing bacteria participating anaerobic oxidation methane. Specific during replacement, unlike those at marine seeps, reflected occurrence lipids such lycopane, 9me-C17 novel DAGEs. As response confined environment characterized concentrations, sulfidic conditions, elevated salinity, ANMEs adapted their membrane compositions cope stressors.

Язык: Английский

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Microbial hydrogen oxidation potential in seasonally hypoxic Baltic Sea sediments

Frontiers in Microbiology, Год журнала: 2025, Номер 16

Опубликована: Апрель 4, 2025

The majority of the organic matter (OM) degradation on seafloor occurs in coastal regions. Since oxygen (O 2 ) becomes quickly depleted top sediments, most OM decomposition is driven by microbial sulfate reduction (SR) and fermentation, latter generating molecular hydrogen (H ). If H not consumed hydrogenotrophic microorganisms accumulates sedimentary porewaters, hindered. Despite importance scavenging for mineralization, knowledge oxidizers their constraints marine sediments still quite limited. Here we investigated role (2 to 5 cm, suboxic-sulfidic) bottom (18 22 sulfidic) from a location exposed seasonal hypoxia SW Baltic Sea. We used April, May August, representative different seasons. spiked respective sediment slurries with incubated them up 4 weeks under O -free conditions. consumption potential, methane production shifts bacterial archaeal 16S rRNA gene amplicons (generated RNA) were assessed over time. variations community compositions pore water geochemistry already gave distinct starting conditions enrichments. Sediments near anoxic favored starter exhibiting highest oxidation potential. Most observed potential appeared associated reducers. putative involvement massively enriched ANME cycling 18 cm horizons conspicuous. While differences potentials studied are likely related (season-depending) overall redox state interstitial waters, influence interconnections could be fully resolved evaluated, demonstrating need further consumption- community-based studies.

Язык: Английский

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Lessons from lipid biomarkers preserved in methane-seep carbonates from the early Permian of Western Australia

Chemical Geology, Год журнала: 2024, Номер 668, С. 122343 - 122343

Опубликована: Авг. 19, 2024

Язык: Английский

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Reinterpretation of lycopane as a biomarker of archaea based on its occurrence in authigenic sulfur-bearing carbonates

Chemical Geology, Год журнала: 2024, Номер unknown, С. 122410 - 122410

Опубликована: Сен. 1, 2024

Язык: Английский

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Authigenic carbonate and native sulfur formation in Messinian (upper Miocene) marine sediments: Sedimentological, petrographical and geochemical constraints

Marine and Petroleum Geology, Год журнала: 2024, Номер 165, С. 106889 - 106889

Опубликована: Май 3, 2024

Язык: Английский

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