PARTIAL CHARACTERIZATION OF THERMOSTABLE PULLULANASE FROM Bacillus Flavothermus KWF-1

Pullulanase is a debranching enzyme that hydrolyses α-1,6-linkages in starch, amylopectin, pullulan and related oligosaccharides. Thermostable pullulanase is being given a special interest in improving the starch conversion process. A thermophilic bacterial strain producing pullulanase enzyme was isolated from local hot spring. The strain was identified as Bacillus flavothermus KWF-1. In the absence of substrate, the crude enzyme was stable in the range of pH 7-10 and 60-90°C. The optimum pH and temperature for the crude enzyme activity were 10 and 80°C, respectively. For pullulanase production, tapioca starch was found to be the best carbon source.