Thermophilic fungi: III. The lipids ofHumicola grisea var.thermoidea

Abstract
The lipids of the thermophilic fungusHumicola grisea var.thermoidea were qualitatively and quantitatively determined. The polar lipids consisted of 38.4–42.3% of the total lipids. The relative per cent phospholipids based upon the total phospholipids were as follows: phosphatidyl choline, 32.3–33.7%; phosphatidic acid, 24.5–31.7%; phosphatidyl ethanolamine, 15.8–20.9%; phosphatidyl inositol, 12.5–13.0%; phosphatidyl serine, 2.3–5.4%; and diphosphatidyl glycerol, 3.9–4.0%. The relatively high concentration of phosphatidic acid may be characteristic of fungi grown at elevated temperatures. Several sterol glycosides (3.1–6.0%) were present in the polar lipids. The neutral lipids consist of triglycerides, 28.6–36.0%; free fatty acids, 5.3–13.5%; sterols, 11.4–13.9%; sterol esters, 1.8–3.0%; and diglycerides, 2.2–3.4%. The sterols and derivatives comprise an unusually large fraction of the total lipids (16.3–22.9%) suggesting a role in thermostability.