Novel archaeal tetraether lipids with a cyclohexyl ring identified in Fayetteville Green Lake, NY, and other sulfidic lacustrine settings

Autor: Ana De Santiago Torio, Tanja Bosak, Xiao-Lei Liu, Roger E. Summons
Rok vydání: 2016
Předmět:
Zdroj: Rapid Communications in Mass Spectrometry. 30:1197-1205
ISSN: 0951-4198
DOI: 10.1002/rcm.7549
Popis: Rationale The meromictic Fayetteville Green Lake (FGL) is of significant geobiological interest because of microbial cycling of sulfur within and below the permanent chemocline and in the euxinic deep waters. Studies of glycerol dibiphytanyl glycerol tetraethers (GDGTs) may help shed light on understanding the activity of archaeal communities in these habitats. Methods Normal-phase and reversed-phase liquid chromatography/mass spectrometry (LC/MS) analysis on total lipid extracts of environmental samples revealed series of GDGTs with different biphytane structures. Comparison of the mass spectrum of biphytane obtained from separated novel GDGTs with that of a synthetic C40 biphytane confirms our structural assignments. Results A unique cyclohexyl ring configured in the middle of a C40 biphytane chain was identified in these novel GDGTs. We suggest the trivial name S-GDGTs for these compounds, where ‘S′ stands for ‘sulfidic’ and ‘six-membered ring’. S-GDGT derivatives composed of biphytanes modified with double bonds and cyclopentane rings were also detected in the samples we analyzed. Intact polar lipid precursors of S-GDGT include compounds with mono- and diglycosyl head groups. Conclusions The carbon isotopic composition of S-GDGTs and their occurrence in FGL, Messel Shale as well as Salt Pond and salt marshes on Cape Cod suggest that S-GDGTs may be produced by chemoautotrophic archaea that prefer sulfidic conditions. Copyright © 2016 John Wiley & Sons, Ltd.
Databáze: OpenAIRE
Externí odkaz: