Lipid composition of Cunninghamella elegans cultivated on n-alkanes]

The ability to oxidize n-alkanes was studied with various species of fungi belonging to the Cunninghamella genus. These fungi are able to assimilate hydrocarbons and to accumulate up to 1.5 g/litre of biomass. The most active strain was Cunninghamella elegans (-) 1204. The amount of lipids formed, and their composition, depended on the length of the carbon chain of oxidized alkane. The content of fat in the cells increased with the length of the hydrocarbon chain. The following lipid fractions have been detected: phospholipids, monoglycerides, diglycerides, triglycerides, sterols, free fatty acids, sterol esters, and hydrocarbons. The qualitative composition of the fractions depended, to a considerable extent, on the n-alkane utilized. Investigation of the fatty-acid composition of intracellular lipids has shown that fatty acids with an even number of carbon atoms are formed from hydrocarbons with an even number of these atoms, while fatty acids both with an even and odd number of carbon atoms are synthesized from hydrocarbons with an odd number of these atoms. The relative content of the acids with the same number of carbon atoms as that of the alkane being utilized increased with the length of the carbon chain.