Stability of Immobilized Candida sp. 99-125 Lipase for Biodiesel Production

Abstract

The stability of the immobilized lipase from Candida sp. 99-125 during biodiesel production was investigated. The lipase was separately incubated in the presence of various reaction components such as soybean oil, oleic acid methyl ester, n-hexane, water, methanol, and glycerol, or the lipase was stored at 60, 80, 100 and 120°C. Thereafter the residual lipase activity was determined by methanolysis reaction. The results showed that the lipase was rather stable in the reaction media, except for methanol and glycerol. The stability study performed in a reciprocal shaker indicated that enzyme desorption from the immobilized lipase mainly contributed to the lipase inactivation in the water system. So the methanol and glycerol contents should be controlled more precisely to avoid lipase inactivation, and the immobilization method should be improved with regard to lipase desorption. The stability of immobilized Candida sp. 99-125 lipase was investigated. The lipase shows excellent stability in the biodiesel reaction medium. Methanol and glycerol showed the most negative effects on the lipase stability. Desorption was the main reason leading to lipase inactivation in the water system. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.