Degradation of complex carbohydrate: Immobilization of pectinase from Bacillus licheniformis KIBGE-IB21 using calcium alginate as a support

Pectinases are heterogeneous group of enzymes that catalyse the hydrolysis of pectin substances which is responsible for the turbidity and undesirable cloudiness in fruits juices. In current study, partially purified pectinase from Bacillus licheniformis KIBGE-IB21 was immobilized in calcium alginate beads. The effect of sodium alginate and calcium chloride concentration on immobilization was studied and it was found that the optimal sodium alginate and calcium chloride concentration was 3.0% and 0.2 M, respectively. It was found that immobilization increases the optimal reaction time for pectin degradation from 5 to 10 min and temperature from 45 to 55 degrees C, whereas, the optimal pH remained same with reference to free enzyme. Thermal stability of enzyme increased after immobilization and immobilized pectinase retained more than 80% of its initial activity after 5 days at 30 degrees C as compared with free enzyme which showed only 30% of residual activity. The immobilized enzyme also exhibited good operational stability and 65% of its initial activity was observed during third cycle. In term of pectinase immobilization efficiency and stability, this calcium alginate beads approach seemed to permit good results and can be used to make a bioreactor for various applications in food industries. (c) 2013 Elsevier Ltd. All rights reserved.