Microbial fatty acid specificity

Strains of Rhodotorula sp., Candida spp. and Langermania sp. cultivated on polyunsaturated oil preferentially incorporated more unsaturated fatty acids. These fat ty acids were used mainly for growth needs whereas the saturated ones accumulated in the microbial cell. The cellular oil and the remaining oil in the culture had a lower degree of unsaturation as compared to the initial oil, and a modified fatty acid composition. Candida lipolytica, in a chemostat continuous culture, incorporated C-18 fatty acids in the order of C-18:3 > C-18:2 > C-18:1 > C-18:0, and accumulated mostly the saturated ones. The specific productivity of the cellular oil and of the oil remaining in the culture medium was 0.036 and 0.487 g g(-1) h(-1), respectively, at dilution rate D = 0.2/h.