“…To this end, Buckles and colleagues (2013) suggested that relative enrichments of an archaeal tetraether lipid, the taxonomically widely distributed glycerol dibiphytanyl glycerol tetraether without cyclopentane rings [i.e. Fortunately, recent advances in the analysis of intact polar lipids (IPLs; Sturt et al, 2004;Wörmer et al, 2013;Zhu et al, 2013) and core lipids (CLs; Knappy et al, 2009;Liu et al, 2012a,b;Becker et al, 2013;Zhu et al, 2014a,b) have already expanded the catalogue of microbial biomarkers and enhanced the ability to find biomarkers associated with the presence of MCG, which could lead to the identification of specific lipid biomarkers. However, the utility of GDGT(0) as universal biomarker for MCG is severely limited due to the widespread occurrence of this lipid in many archaeal phyla (e.g.…”