TABLE 3.

Core lipid composition of the biomass (totCLs) and of the total lipid extract (CLs from IPLs) of T. barophilus.

	Diethersa						Tetraethersa						Total
	DGD I			PSGD XII			GDGT0 XVIII			GTGT0 XXII
	μ g	fg cell–1	Rel%	μ g	fg cell–1	Rel%	μ g	fg cell–1	Rel%	μ g	fg cell–1	Rel%	fg cell–1	D/T
TotCLs	22.2	0.1	28	6.1 × 10–2	3.1 × 10–4	Traces	56.8	0.3	72	0.4	2.2 × 10–3	Traces	0.4	0.39
CLs from IPLs	14.6	7.3 × 10–2	80	4.2 × 10–2	2.1 × 10–3	Traces	3.6	1.8 × 10–2	20	3.1 × 10–2	1.5 × 10–4	Traces	9.1 × 10–2	4.0

DGD, dialkyl glycerol diethers; PSGD, phytanylsesterterpanyl glycerol diethers; GDGT0, glycerol dialkyl glycerol tetraethers with no cyclopentane ring; GTGT0, glycerol trialkyl glycerol tetraethers with no cyclopentane ring; D/T, diethers over tetraethers ratio; Rel%, molar relative proportion; μg, absolute lipid quantity in μg; fg cell^–1, cellular lipid abundance in fg cell^–1 calculated with an average cell number of 2.0 × 10⁸ cell mL^–1; ND, not detected. Traces, < 1%. ^aRelative proportions account for protonated adducts in APCI positive mode and were calculated assuming a response factor of 0.42 for diethers and 0.57 for tetraethers relative to the internal standard C₄₆-GTGT, or of 0.74 for diethers relative to tetraethers (refer to methods).