Application of binary immobilized Candida rugosa lipase for hydrolysis of soybean oil

Lipase was immobilized to chitosan beads by a binary method and its catalytic efficiency in the hydrolysis of soybean oil was investigated. In the first step, the hydroxyl groups of chitosan were activated with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and lipase molecules were coupled to the active hydroxyl groups. In the second step, more lipase molecules were cross-linked through its amino groups to chitosan by using glutaraldehyde. The effects of temperature, pH and oil to water ratio on the conversion, pH and thermal stability, reusability, storage stability and the kinetic properties were also investigated. Under optimal conditions, 88% of the oil taken initially was hydrolyzed after 5 h. Better thermal stability was exhibited by the immobilized lipase and the pH stability was comparable to that of soluble lipase. Storage for 30 days at 4 °C, showed that the immobilized enzyme did not lose its activity. The relative activity upon six repeated uses was 80%.