Author(s): LiJung Yin
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 electro-phoretical 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, re-spectively, 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 Mn 2+ and Co 2+ , but inhibited by SDS, p-CMB, DTT, Hg + , Cd 2+ , Fe 2+ and Fe 3+ . According to substrate speci-ficity, the purified cellulase has high specificity to CMC and was considered to be an endo-1,4-glucanase.