Production of isopropyl cis-6-hexadecenoate by regiospecific desaturation of isopropyl palmitate by a double mutant of a Rhodococcus strain

Resting cells of a double mutant noted as KSM-MT66, derived from Rhodococcu s sp. strain KSM-B-3 by UV irradiation, were found to cis-desaturate isopro pyl hexadecanoate, yielding isopropyl cis-6-hexadecenoate. Addition of sodi um glutamate (1.0%), Mg SO4 (2 mM), and thiamine (2 mM) increased the produ ctivity of the unsaturated product in phosphate buffer. Optimal temperature and pH for the reaction were around 26 degrees C and 7, respectively. Unde r the optimized conditions, more than 50 g/l of isopropyl cis-6-hexadecenoa te was produced after a 3-day incubation by resting cells of the mutant. Th us, cis-6-hexadecenoic acid, the main component of human sebaceous lipids, can be manufactured economically by the rhodococcal bioconversion.