Cellular fatty acids derived from normal alkanes by Candida rugosa.

In an attempt to examine the specific metabolic relationship between the alkane substrates and lipid products the pattern of formation of cellular lipid, especially fatty acids, has been studied in the course of incubation of cells of C. rugosa with n-alkanes in mineral medium. C18:2, C18:1, C16:1 and C16:0 fatty acids were the major products formed, irrespective of the odd or even chain length of the alkane used as substrate. These unsaturated fatty acids reached a maximum in the stationary phase. In the case of cells grown on odd-chain n-alkanes (from C11 to C19), the proportion of odd-chain cellular fatty acids were markedly high, reaching 77--88% in the n-pentadecane and heptadecane-grown cells. The resulting acids are then metabolized by beta-oxidation or inserted directly or after elongation with C2-units into the cellular fatty acids. The total lipid content of n-alkane (n-C10-C20) grown cells in the stationary phase was 16.3--19.0% of th dry cell weight, which was about three times as much as that of glucose-grown cells. The chain length of alkane substrates had a significant effect on the lipid content. Ergosterol production from n-hexadecane was twice higher than that from glucose.