Mining and application of lipase from Clostridium acetobutylicum with higher catalytic activity for butyl butyrate production

Butyl butyrate is extensively applied in beverage, fragrances, food and daily cosmetics industries. However, the most commonly used commercial enzymes for butyl butyrate biosynthesis have low specificity as they can catalyze the synthesis of a variety of short-chain fatty acid esters (SCFAE). Therefore, it is necessary to find lipases with higher specificity for the esterification synthesis of butyl butyrate. In this study, the endogenous lipase of Clostridium acetobutylicum was first excavated and analyzed, and then successfully displayed on the surface of Escherichia coli. When it was applied in butyl butyrate synthesis, its catalytic efficiency reached 85 % of that of commercial enzyme. Importantly, its specificity for butyl butyrate synthesis was higher, and lower titer of by-products was generated than commercial lipase. Additionally, the catalytic activity lasted for more than 35 days when it was immobilized by sodium alginate hydrogel. The successful cell surface-displayed of the lipase can effectively eliminate the addition of commercial lipase in the process of butyl butyrate biosynthesis.