Fig. 2.

Distributions of archaeal isoprenoidal hydrocarbons and glycerol diethers in compartments of the chimney-like structures (mat type I with ANME-2 as predominant methanotrophs and the ANME-1-dominated mat type II). Shown are reconstructed partial ion chromatograms of strongly ¹³C-depleted lipids (δ ¹³C < –78‰). Int, intensity; Rt, retention time. (A) Isoprenoidal hydrocarbons and glycerol diethers obtained from mat type I. (B) Isoprenoidal hydrocarbons and glycerol diethers of the mat type II. Alcohols from alkaline hydrolysis [measured as N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) derivatives]. Peaks: 1, crocetane (2,6,11,15-tetramethylhexadecane); 2, unsaturated crocetanes with up to two double bonds; 3, PMI (2,6,10,15,19-pentamethylicosane); 4, unsaturated PMIs with up to five double bonds; 5, archaeol (2,3-di-O-phytanyl-sn-glycerol); and 6, sn-2-hydroxyarchaeol (2-O-3-hydroxyphytanyl-3-O-phytanyl-sn-glycerol).