The Effect of Ethanol Solvent on Thermostability and Esterification Activity of Immobilized Candida Rugosa Lipase on Celite

Lipase is an enzyme commonly applied as a catalyst in the food industry, the synthesis of bioplastics, and the production of biodiesel. Candida rugosa lipase (CRL) is one of the widely used lipases due to its high selectivity and activity. However, high operating temperatures can denature enzymes, affecting enzyme activity due to structural changes. An enzyme can be immobilized on a supporting matrix to improve stability. Ethanol as an immobilization solvent may also increase the thermostability and esterification activity. This study examines the effect of ethanol solvent on the thermostability of immobilized Candida rugosa lipase. Immobilization was carried out on the Celite-545 matrix in buffer/ethanol solution. Different operating conditions such as enzyme concentrations, immobilization temperatures, immobilization time, and immobilization pH were observed. The immobilized enzyme activity was determined by esterification reaction using butyric acid and 1-butanol as substrates and isooctane as reaction medium. The results showed that immobilization increased the esterification activity by 76% at 37°C. Thermostability of immobilized enzyme was also enhanced by 29-51%, depending on the esterification temperature.