Purification and characterization of Chitinase from a new species strain, pseudomonas sp. TKU008

The chitinase-producing strain TKU008 was isolated from soil in Taiwan, and it was identified as a new species of Pseudomonas. The culture condition suitable for production of chitinase was found to be shaking at 30°C for 4 days in 100 ml of medium containing 1% shrimp and crab shell powder, 0.1% K₂HPO₄, and 0.05% MgSO₄7H₂O (pH 7). The TKU008 chitinase was suppressed by the simultaneously existing protease, which also showed the maximum activity at the fourth day of incubation. The molecular mass of the chitinase was estimated to be 40 kDa by SDS-PAGE. The optimum pH, optimum temperature, pH stability, and thermal stability of the chitinase were pH 7, 50°C, pH 6-7, and <50°C, respectively. The chitinase was completely inhibited by Mn²+ and Cu²+. The results of peptide mass mapping showed that 11 tryptic peptides of the chitinase were identical to the chitinase CW from Bacillus cereus (GenBank Accession No. gi 45827175) with a 32% sequence coverage.