Enantioselective transesterification of glycidol catalysed by a novel lipase expressed from Bacillus subtilis

A novel plasmid (pBSR2) was constructed by incorporating a strong lipase promoter and a terminator into the original pBD64. The lipase gene from Bacillus subtilis strain IFFI10210 was cloned into the plasmid pBSR2 and transformed into B. subtilis A.S.1.1655 to obtain an overexpression strain. The recombinant lipase [BSL2 (B. subtilis lipase 2)] has been expressed from the novel constructed strain and used in kinetic resolution of glycidol through enantioselective transesterification. The effects of reaction conditions on the activity as well as enantioselectivity were investigated. BSL2 showed a satisfying enantioselectivity (E>30) under the optimum conditions [acyl donor: vinyl butyrate; the mole ratio of vinyl butyrate to glycidol was 3:1; organic medium: 1,2-dichloroethane with water activity (a(w))=0.33; temperature 40 degrees C]. The remaining (R)-glycidol with a high enantiomeric purity [ee (enantiomeric excess) >99%] could be obtained when the conversion was approx. 60%. The results clearly show a good potential for industrial application of BSL2 in the resolution of glycidol through enantioselective transesterification.