Studies on synthesis of short chain alkyl esters catalyzed by goat pregastric lipase

Goat pregastric lipase, in the form of a suspended enzyme powder, was found to be active in catalyzing the synthesis of alkyl esters in anhydrous orga nic solvents. The rate of catalyzed synthesis of esters was very dependent on the solvent medium, and maximum activity was found when a hydrocarbon wa s used as the solvent. The optimal temperature for the catalyzed synthesis ranged from 30 to 40 degrees C and the maximal temperature was 35 degrees C for the synthesis of butyl caproate in isooctane. The selectivity for the carbon-chain length of the fatty acid by the lipase was similar to that see n in hydrolysis reactions in aqueous solution, and the optimal rate of synt hesis of alkyl esters was found for synthesis of the esters which had 8 or 10 carbons in the alkyl moieties from the two individual substrates. The ra te of synthesis was also dependent on the water content in the system, with maximum activity occurring at 1% w/w water in isooctane. (C) 1999 Elsevier Science B.V. All rights reserved.