Glycerol as a carbon source for lipase production by the fungusrhizopus delemar

The ability of the fungus Rhizopus delemar to synthesize lipase (glycerol ester hydrolase, E.C. 3.1.1.3) when grown on glycerol as the prime carbon source was investigated. Glucose, glycerol and olive oil all supported fungal growth and lipase production. Maximum net and specific lipase activities obtained in glycerol were greater than those obtained in glucose and olive oil, and were reached earlier and maintained longer during growth. In glucose media, lipase activity did not appear until the glucose had been consumed. Differences in lipase activity between glycerol and glucose media were not due to pH‐mediated lipase inactivation. In both glucose and glycerol media the appearance of lipolytic activity coincided with the appearance of lipase polypeptide. The data are consistent with the postulate that lipase synthesis is subject to catabolite repression by glucose. These studies identify a simple, single‐phase medium for lipase production and establish the utility of glycerol for amplifying enzyme levels.