Comparative study of kinetic and interfacial properties of a novel Rhizopus oryzae lipase and ROL29

Abstract

We compared several kinetic and interfacial properties of a lipase from a novel strain of Rhizopus oryzae (ROLw) with ROL29 lipase. In contrast to ROL29, ROLw was able to hydrolyze triolein emulsion in the absence of any additive, like bovine serum albumin (BSA). Furthermore, unlike Rhizopus oryzae lipase (ROL29), kinetic study of ROLw lipase shows linear dependency when using tributyrin emulsion as substrate. ROLw can tolerate, more efficiently than ROL29, the accumulation of long-chain free fatty acids at the interface when olive oil emulsion was used as substrate. The critical surface pressure πc of penetration into phosphatidyl choline from egg yolk films was found to be 23 mN/m with ROLw, in contrast to a value of 10 mN/m obtained with ROL29. The effect of calcium ion and synthetic detergent on the two lipases was studied. In contrast to ROL29, ROLw was activated in the presence of 100 lmoles TX-100. No significant difference on the two lipase activity was observed in presence or absence of calcium ion.

Keywords

• Rhizopus oryzae lipase (ROLw)
• ROL29
• Interfacial denaturation
• Critical pressure
• Detergent
• Calcium ion