Purification and characterization ofa cellulase from bacillus subtilis YJ1

Abstract

Broth incubated with Bacillus subtilis YJ1 at 37°C for 36 h was collected and removed bacterial cells by passing through a 0.45 μm membrane. A cellulase was purified to electrophoretical homogeneity by ammonium sulfate precipitation, Macro-Prep ion exchange and Bio-Gel P-100 chromatography. The recovery and purification fold were 9.7% and 289, respectively, after Bio-Gel P-100 Chromatograph. The purified cellulase, with a molecular mass (M) of 32.5 kDa, had an optimal pH and temperature at 6.0 and 50-60°C, respectively. It was stable at pH 6.0-7.5 and <50°C. The purified cellulase was activated by Mn2+ and Co2+, but inhibited by SDS, p-CMB, DTT, Hg+, Cd2+, Fe2+ and Fe3+. According to substrate specificity, the purified cellulase has high specificity to CMC and was considered to be an endo-l,4-glucanase.