Synthesis of butyl acetate in n-heptane by the recombinant CS-2 lipase immobilized on kieselguhr

Ren Peng, Jinping Li, Dongzhi

Abstract

Flavor esters are an important kind of flavor compounds, which are widely used in the food and pharmaceutical fields. The recombinant CS-2 lipase was immobilized after purification for which kieselguhr showed 18.5% of binding efficiency with 150.7 U/g of lipase activity. The immobilized lipase was used for the synthesis of butyl acetate in n-heptane. The factors affecting the synthesis of butyl acetate were investigated in the study. The results showed that the conversion of 98.2% was achieved under the following condition: reaction time (10 h); water activity (0.02); reaction temperature (55℃); the concentration of acetic acid and n-butanol (0.1 mol/L and 0.2 mol/L); the addition of 4 Šmolecular sieve (0.5 g) at 8h of reaction time. The conversion of substrate decreased only from 98.2% to 87.4% after five cycles in use of the immobilized lipase.