Characterization of thermostable chitinase from Bacillus licheniformis B2

Abstract

Chitinases is an enzyme capable of degrading chitin into oligomers to produce chitin derivatives products which are more useful. Thermostable-chitinase is of important in the relevant industrial application, since the degradation process oftently requires prety high temperature. This research report a characterization of chitinase isolated from thermophilic microorganism. The chitinase was obtained from Bacillus licheniformis B2 isolated from Ijen hot spring, East Java. It has the best chitinolytic activity at pH 7 when colloidal chitin was used as substrate. The enzyme exhibited activity in broad temperature range, from 50 °C to 70 °C, optimally at 55 °C. It was stable at 50 °C up to 90 min, at 60 °C up to 60 min and at 70 °C up to 30 min. At neutral pH this enzyme has negative charge but further purification is needed to determine its pI. The Km and Vmax of this chitinase for colloidal chitin were 101.96 mg mL -1 and 2.72 μmol (min mL)-1, respectively. Addition of NaCl, KNO3 and MgSO4 decreased the activity of chitinase following mixed inhibitor mode. This enzyme should be a good candidate for applications in the recycling of chitin waste.