Partial Purification and Characterization of Cellulolytic Enzyme from Bacillus pantothenticus Isolated from a Dumpsite

Abstract

Cellulose hydrolyzing organism, Bacillus pantothenticus, was isolated from a dumpsite soil. Partial purification of the enzyme with precipitation with 60% chilled acetone and on Biogel P-100 gel filtration yielded an enzyme with specific activity of 253.50, 10.40% yield and purification fold of 2.41. The apparent Km and Vmax for Carboxymethylcellulose (CMC) hydrolysis was 1.167 mg/ml and 0.833 μg of glucose/ml/min respectively. The native molecular weight of the enzyme from B. pantothenticus was estimated as 51.48 kDa. The cellulase produced showed activity over broad range of temperature (30-70°C) with maximum activity at 60°C. The enzyme also showed activity in a wide pH range of 4-11 with optimum activity at pH 4.5. At concentration of 10 mM, KCl, MgCl2, NaCl and NiCl2 inhibited the enzyme while CoCl2 activated the enzyme. The enzyme showed highest activity with microcrystalline cellulose as substrate followed by CMC. Significant activity was also observed with organic substrates such as sugarcane bagasse, orange bagasse and corn cub. The study concluded that the cellulose enzyme obtained had suitable catalytic properties for use in biodegradation of waste and other industrial applications.