Purification and characterization of organic solvent-tolerant lipase from Streptomyces sp. OC119-7 for biodiesel production

This study determined the lipolytic activity of Streptomyces isolates and then purified and characterized the lipase obtained from Streptornyce.s sp. OC 119-7, the isolate demonstrated to have the high lipolytic activity. Ammonium sulfate precipitation and gel filtration chromatography were used to purify the extracellular alkaline lipase obtained from StTeptornyces sp. OC 119-7, and resulted in 5.52-fold purification with 68.055 U/mg specific activity. The enzyme showed optimal activity at pH 8.0 and 50 degrees C, with stability in a temperature range of 40-60 degrees C and at pHs of >= 7. Enzyme activity was enhanced by the presence of Ca2+ and Mg2+ and inhibited by the presence of Mn2+, Co2+, Cu2+, Zn2+, K+, Na+ and PMSF. OC 119-7 lipase displayed stability against surfactants and organic solvents. Lip0C 119-7 catalyzed transesterification of olive oil with methanol, suggesting that this lipase may be a potential enzymatic catalyst for biodiesel production. (C) 2014 Elsevier Ltd. All rights reserved.