Transesterification activity of a novel lipase from Acinetobacter venetianus RAG-1

Transesterification activity and the industrial potential of a novel lipase prepared from Acinetobacter ventiatus RAG-1 were evaluated. Purified lipase samples were dialyzed against pH 9.0 buffer in a single optimization step prior to lyophilization. The enzyme and organic phase were pre-equilibrated (separately) to the same thermodynamic water activities (a(w)) ranging from a(w) 0.33 to 0.97. Production of 1-octyl butyrate by lipase-catalyzed transesterification of vinyl butyrate with 1-octanol in hexane was monitored by gas chromatography. Production of 1-octyl butyrate and initial rate of reaction depended on water activity. Product synthesis and rate of transesterification increased sharply with increase from a(w) 0.33 to 0.55. Highest product concentration (218 mM) and rate of reaction (18.7 mu mol h(-1) . 10 mu g protein) were measured at a(w) 0.86. Transesterification activity in hexane represented 32% of comparable hydrolytic activity in aqueous buffer.