A lipase from Bacillus cereus C71 was purified to homogeneity by ammonium sulfate precipitation, followed by Phenyl-Sepharose chromatography, DEAE ion exchange chromatography and CIM (R) QA chromatography. This purification procedure resulted in a 1092-fold purification of lipase with 18% yield. The molecular mass of the purified enzyme was determined to be approximately 42 kDa by SDS-PAGE and mass spectrometer. The lipase was stable in the pH range of 8.5-10.0, with the optimum pH 9.0. The enzyme exhibited maximum activity at 33 degrees C and retained 92% of original activity after incubation at 35 degrees C for 3 h. The protein hydrolyzed p-nitrophenyl esters with acyl chain lengths between C4 and C12. Enzyme activity was strongly inhibited in the presence of Cu2+ and Zn2+ but promoted by non-ionic surfactants. The lipase demonstrated higher enantioselectivity toward R-isomer of ethyl 2-arylpropanoate than the commercial lipases, and can be used potentially as a catalyst to prepare optically pure pharmaceuticals. (C) 2007 Elsevier Ltd. All rights reserved.