ABSTRACT
Aim: To identify isolates for industrial production of pectinase. Methodology: The isolates were screened for pectinolytic activity using pectin as substrate. Enzyme activity was expressed as mg of glucose equivalent released per ml of crude enzyme solution per second. The kinetic parameters of the enzyme were determined to obtain the optimum pH, temperature, Km and Vmax. Pectinase produced from Bacillus subtillis was immobilized on chitosan and its activity was compared with that of free enzyme. Results: Pectinase from Bacillus subtilis was screened to have the highest enzymatic activity among bacterial isolates while pectinase from Aspergillus niger had the highest enzymatic activity among fungal isolates. High yield of pectinase enzyme was obtained from B. subtilis after 24hrs with activity of 4.01×10-4 mg/ml/sec while high yield of pectinase was obtained from A. niger on the 5th day with activity of 2.07×10-4 mg/ml/sec. The optimum pH for pectinase produced from B. subtilis and A. niger were 8 and 6, respectively. The optimum temperature for pectinase from B. subtilis and A. niger were at 50ºC and 40ºC, respectively. The Vmax and Km of pectinase from B. subtilis and A. niger were 16.88×10-4 (mg/ml/sec) and 10 (mg/ml); 9.29×10-4 (mg/ml/sec) and 30 (mg/ml), respectively. Optimum temperature and pH of immobilized pectinase were 70ºC and 4.0, respectively. Residual activity of immobilized enzyme was 92% after storage at 4ºC for 14 days. Conclusion: This study revealed that Bacillus subtilis from snail gut may be considered as a good candidate for industrial production of pectinase.