Production And Characterization Of The Lipase From Penicillium Expansum PED-03 By Solid State Fermentation

The solid state fermentation of the lipase from Penicillium expansum PED-03, and its characterization and application in the resolution of racemic (R, S)-2-octanol were investigated.The lipase production was performed by Penicillium expansum PED-03 with solid state fermentation. It was found that soybean meal and wheat bran were the suitable nitrogen and carbon source for lipase production, respectively. The optimal ratio of soybean meal and wheat bran was 4:1. The optimum water content of substrate, inoculation dosage, and culture temperature were 50%, 10% and 24℃, respectively. The lipase activity reached 2100U/g under the optimized conditions for 4days.The characterization of lipase from Penicillium expansum PED-03 was studied. The lipase showed highest activity at pH 9.5 and 35℃, and was stable under 50℃ and during the pH range 7.0-9.5. Ca²⁺, Mg²⁺and Na⁺ stimulated the enzyme activity significantly, while Zn²⁺, Mn²⁺, Cu²⁺, Fe²⁺and Hg²⁺had an inhibitory effect.The resolution of (R,S)-2-octanol was performed by the lipase from Penicillium expansum PED-03 lipase immobilized on USY molecular sieve. n-Hexane and vinyl acetate were found to be the suitable solvent and acyl donor, respectively. The optimal ratio (vinyl acetate:2-octanol) was 1.5. The conversion of the reaction catalyzed by the lipase from Penicillium expansum PED-03 immobilized on USY molecular sieve reached 48.84% with excellent enantioselectivity in n-hexane with 0.8% (v/v) water for 24 h, which showed a good application potential in the production of optically pure (R,S)-2-octanol.