Production, properties and application to nonaqueous enzymatic catalysis of lipase from a newly isolated Pseudomonas strain

A potent bacterium for lipase production was isolated from soil and identif ied as Pseudomonas species. It produced lipase constitutively. A mutant of this strain with a lipase productivity 3.25-fold higher was obtained by tre atment with ultraviolet (UV) and nitrosoguanidine (NTG). Its fermentation c ondition was optimized to a lipase yield of 87.5 U/ml. The lipase had maxim um activity at pH 9.0 and 45 degrees C. It was stable at pHs from 7.0 to 11 .0 and below 60 degrees C. The effects of metal ions, surfactants and bile salts were also studied. The lipase was 1,3-specific. In organic solvents, the thermal stability of the lipase was significantly enhanced. Its optimum temperature was also slightly increased. The optimum water activity was fo und between 0.5 and 0.6. The lipase was successfully applied in organic pha se to catalyze the glycerolysis of palm oil for monoglyceride (MG) producti on, and the enantioselective esterification of (R,S)-2-octanol. The enantio selectivity of the lipase could be enhanced substantially by treatment with an amphipathic. (C) 2000 Elsevier Science Inc. All rights reserved.