Lipase-Catalyzed Transesterification Synthesis of Geranyl Acetate in Organic Solvents and Its Kinetics

摘要

Lipase-catalyzed geraniol synthesis of geranyl acetate via transesterification with vinyl acetate in organic solvents was investigated. The lipase from Pseudomonas fluorescens was identified as the optimal enzyme and vinyl acetate was employed as both acyl donor and solvent through transesterification. The effects of various parameters on transesterification, including enzyme loading, temperature, and agitation speed, were optimized. The optimal reaction temperature was 30℃. The external diffusion limitation could be greatly reduced by increasing the agitation speed to 240 rpm, and the internal diffusion could be ignored. Lipase operational stability research revealed that lipase activity has no obvious loss after nine batch cycles. A kinetic model based on the ping-pong bi-bi mechanism without inhibition by geraniol and geranyl acetate using the King-Altman method was proposed. Matlab was applied to simulate the model parameters. The experimental values could be satisfactorily fitted to the simulated values with a relative error of 1.88%.