Effects of temperature variation on the fatty acid composition of Candida utilis

Abstract

The fatty acid compositions of various cultures of the yeast Candida utilis NCYC 321 were analyzed by gas-liquid chromatography of the methyl esters obtained from the lipids in chloroform-methanol extracts of the cells. Over a wide range of growth conditions C. utilis contained mainly 16:0, 16:1, 18:1, 18:2, and 18:3 fatty acids in variable proportions. The most variable aspect of the fatty-acid composition of C. utilis was in the relative proportions of 18:1, 18:2, and 18:3 acids. During batch growth at 30 C, the relative proportions of 18:3 decreased, whereas 18:1 increased as the cultures aged. Batch cultures grown at low temperatures maintained higher proportions of 18:3 acids than cultures grown at 30 C. When stationary cultures were replenished with fresh medium under aerobic conditions, there was an abrupt increase in the proportion of 18:3 with a concomitant decrease in 18:1 acids in the cells. The fatty acid composition of cells grown in a chemostat at 30 C did not vary much in response to changes in either the growth rate or the growth-limiting substrate. Chemostat-grown cells contained highest proportions of 18:3 acid when grown under conditions of glucose-limitation at low temperatures.