GLYCEROL AS A CARBON SOURCE FOR LIPASE PRODUCTION BY THE FUNGUS RHIZOPUS-DELEMAR

The ability of the fungus Rhizopus delemar to synthesize lipase (glyce rol 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 s upported fungal growth and lipase production. Maximum net and specific lipase activities obtained in glycerol were greater than those obtain ed in glucose and olive oil, and were reached earlier and maintained l onger during growth. In glucose media, lipase activity did not appear until the glucose had been consumed. Differences in lipase activity be tween glycerol and glucose media were not due to pH-mediated lipase in activation. In both glucose and glycerol media the appearance of lipol ytic activity coincided with the appearance of lipase polypeptide. The data are consistent with the postulate that lipase synthesis is subje ct to catabolite repression by glucose. These studies identify a simpl e, single-phase medium for lipase production and establish the utility of glycerol for amplifying enzyme levels.