Eucaryote thermophily: role of lipids in the growth of Talaromyces thermophilus.

The effects of growth temperature on the fatty acid composition of the phospholipids of the fungus Talaromyces thermophilus were investigated. This thermophilic organism was unable to increase the degree of unsaturation of its fatty acids when shifted from high to low growth temperatures. Inhibition of fatty acid synthesis by the antibiotic cerulenin was reversed by the addition of a mixture of palmitic, stearic, and oleic acids and ergosterol. The data obtained were consistent with the hypothesis that the thermophilic character of T. thermophilus is due to metabolic limitations that restrict its ability to regulate membrane fluidity.