Publication Date:
2024-02-02
Description:
Butanetriol and pentanetriol dialkyl glycerol tetraethers (BDGTs and PDGTs) are membrane lipids recently discovered in sedimentary environments and in the methanogenic archaeon Methanomassiliicoccus luminyensis. They possess an unusual structure, which challenges fundamental assumptions in lipid biochemistry. Indeed, they bear a butanetriol or a pentanetriol backbone instead of a glycerol at one end of their core structure. In this study, we unambiguously located the additional methyl group of the BDGT compound on the C3 carbon of the lipid backbone via high-field two-dimensional NMR experiments. We further systematically explored the abundance, distribution and isotopic composition of BDGTs and PDGTs as both intact polar and core lipid forms in marine sediments collected in contrasting environments of the Mediterranean Sea and Black Sea. In addition, relatively 13C-depleted BDGTs from the Rhone delta and from the Black Sea are in agreement with a probable methanogenic source for these lipids. In line with this interpretation, high proportions of intact polar BDGTs and PDGTs were detected in the deeper methane-laden sedimentary layers. However, relatively 13C enriched BDGTs and contrasting headgroup distribution patterns of BDGTs and PDGTs in sediments of the Eastern Mediterranean Sea imply that additional archaeal groups also produce these unique lipids.
Keywords:
Acyclic butanetriol dialkyl glycerol tetraethers in core lipids, per unit mass organic carbon; Center for Marine Environmental Sciences; DARCLIFE; DARCSEAS II; Deep subsurface Archaea: carbon cycle, life strategies, and role in sedimentary ecosystems; Depth, bottom/max; DEPTH, sediment/rock; Depth, top/min; Dicyclic butanetriol dialkyl glycerol tetraethers in core lipids, per unit mass organic carbon; Diglycosidic butanetriol dialkyl glycerol tetraethers, per unit mass organic carbon; Diglycosidic pentanetriol dialkyl glycerol tetraethers, per unit mass organic carbon; Event label; GC; GeoB15103-1; GeoB15103-2; GeoB15103-3; GeoB15104-1; GeoB15104-2; GeoB15105-2; GeoB15105-4; GeoB17302-5; GeoB17304-3; GeoB17306-1; GeoB17306-2; GeoB17307-5; GeoB17307-8; GeoB17308-1; GeoB17308-4; Gravity corer; Identification; M84/1; M84/1_119-1; M84/1_120-1; M84/1_121-1; M84/1_122-1; M84/1_123-1; M84/1_127-1; M84/1_129-1; MARUM; Meteor (1986); Monocyclic butanetriol dialkyl glycerol tetraethers in core lipids, per unit mass organic carbon; Monoglycosidic butanetriol dialkyl glycerol tetraethers, per unit mass organic carbon; Monoglycosidic pentanetriol dialkyl glycerol tetraethers, per unit mass organic carbon; MUC; MultiCorer; Pentanetriol dialkyl glycerol tetraethers in core lipids, per unit mass organic carbon; POS450; POS450_576-5; POS450_580-3; POS450_582-1; POS450_583-5; POS450_584-1; POS450_585-3; POS450_586-1; POS450_587-1; Poseidon; Proposed International Geo Sample Number; Western Mediterranean Sea
Type:
Dataset
Format:
text/tab-separated-values, 455 data points
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