Purification and characterization of chitinase from a new species strain Pseudomonas sp. TKU008.

The chitinase producing strain TKU008 was isolated from the 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 shaken at 30 degrees C for 4 days in 100 mL of medium containing 1% shrimp and crab shell powder, 0.1 % K2HPO4 and 0.05% MgSO4 . 7 H2O (pH 7). The TKU008 chitinase was suppressed by the simultaneously existing protease, which also showed the maximum activity at the forth 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 degrees C, pH 6-7, and 50 degrees C, respectively. The chitinase was completely inhibited by Mn2+ and Cu2+. The results of peptide mass mapping showed that eleven tryptic peptides of the chitinase were identical to a chitinase CW from Bacillus cereus (GenBank accession number gi 45827175) with a 32 % sequence coverage.