Comparative Studies of Lipase from Rhizopus Delemar in Various Microemulsion Systems

Abstract

Hydrolysis of triglycerides by lipase from Rhizopus delemar has been studied in three different types of microemulsion systems. Microemulsions were prepared by using anionic (AOT), cationic (CTAB) and nonionic (C₁₂E₄) surfactants. Various parameters affecting the reaction, such as temperature, pH optimum, water content (R = [H₂O]/[surfactant]), as well as K_m.app and V_app, were determined using triolein and tributyrin as substrates. Maximum enzyme activity was obtained at R = 9, T = 30°C and pH = 6.5 in anionic surfactant systems, while in cationic, it was found at R = 7, T = 22.5°C and pH = 5.8. The stability of the enzyme was also studied in anionic and cationic systems under various conditions. The enzymatic reaction was also found to be very slow when it was studied in the C₁₂E₄ systems.

Key Words:

• lipase
• microemulsion
• reverse micelles