Lipid composition of strains of the fungus Ustilago zeae (Beckm.) differing as regards their hybridization type

The composition of the intracellular lipids was studied in four strains of Ustilago zeae differing as regards their hybridization type. In all strains, irrespective of the hybridization type, the bulk of the lipids are formed during the first three days of growth and constitute 43.2--55.7% of the weight of the dry cells. It was established that the total lipid fraction is composed of: phospholipids + monoglycerides, sterols, free fatty acids, diglycerides and sterol esters. The qualitative composition of the total lipids was found to be identical in all four strains regardless of the time of incubation of the cultures. While the qualitative composition remains constant, the ratio of the individual fractions changes in the various strains during the process of incubation. However, compatible strains with respect to hybridization do not differ as regards the amount of individual lipid fractions, while strains incompatible with respect to hybridization differ as regards this trait.