Structural elucidation and environmental distributions of butanetriol and pentanetriol dialkyl glycerol tetraethers (BDGTs and PDGTs)

Coffinet, Sarah, Meador, Travis B., Mühlena, Lukas, Becker, Kevin W., Schröder, Jan, Zhu, Qing-Zeng, Lipp, Julius S., Heuer, Verena B., Crump, Matthew P. and Hinrichs, Kai-Uwe (2020) Structural elucidation and environmental distributions of butanetriol and pentanetriol dialkyl glycerol tetraethers (BDGTs and PDGTs) Biogeosciences, 17 (2). pp. 317-330. DOI 10.5194/bg-17-317-2020.

[img]
Preview
Text
bg-17-317-2020-1.pdf - Published Version
Available under License Creative Commons: Attribution 4.0.

Download (2110Kb) | Preview
[img]
Preview
Text
bg-17-317-2020-supplement.pdf - Supplemental Material
Available under License Creative Commons: Attribution 4.0.

Download (818Kb) | Preview

Supplementary data:

Abstract

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 nuclear magnetic resonance (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. High proportions of intact polar BDGTs and PDGTs in the deeper methane-laden sedimentary layers and relatively C-13-depleted BDGTs, especially in the Rhone Delta and in the Black Sea, are in agreement with a probable methanogenic source for these lipids. However, contributions from heterotrophic Archaea to BDGTs (and PDGTs) cannot be excluded, particularly in the eastern Mediterranean Sea, and contrasting BDGT and PDGT headgroup distribution patterns were observed between the different sites studied. This points to additional, non-methanogenic, archaeal sources for these lipids.

Document Type: Article
Research affiliation: MARUM
OceanRep > GEOMAR > FB2 Marine Biogeochemistry > FB2-BI Biological Oceanography
Refereed: Yes
DOI etc.: 10.5194/bg-17-317-2020
ISSN: 1726-4189
Expeditions/Models:
Date Deposited: 10 Feb 2020 13:23
Last Modified: 10 Feb 2020 13:23
URI: http://eprints.uni-kiel.de/id/eprint/48964

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...