PROPERTIES AND PARTIAL PURIFICATION OF A PSEUDOMONAS CEPACIA LIPASE

Abstract

A high lipolytic activity (65 umol/ml min.) was observed in the supernatant of Pseudomonas cepacia DSM 50181 after growth on olive oil. The crude lipase was investigated with respect to substrate specifity, pH- and temperature optima. The hydrolysis of short chain triglycerides and of the unsaturated triolein indicated a higher lipolytic activity than in the case of long chain substances (37°C). The p-nitrophenyl- esters of fatty acids showed maximum activity for the palmitate. This was the same maximum which was observed for triglycerides in the range from C12 to C18 at 75°C. An inhibition of lipolytic activity was noticed by adding oleic acid during the hydrolysis of olive oil. Furthermore an inactivation of the lipase occured when the interface liquid/gaseous was increased. The addition of an inert lipophilic substance or of detergents could neutralize this effect. A partial purification of the lipolytic enzyme could be achieved by liquid/liquid extraction and ionexchangechromatography. This enrichment procedures led to a purification factor of 55 with a recovery of 30%. Isoelectric focussing showed a main protein band at pl 7.1.