Purification and biochemical characterization of chitinase of Aeromonas hydrophila SBK1 biosynthesized using crustacean shell

Valorization of shrimp shells as the sole C/N source for chitinase biosynthesis by Aeromonas hydrophila SBK1 was carried out in solid state fermentation. Chitinase (58.6 kDa) was purified from the ferments to homogeneity have Km and Vmax of 5.5 mg/ml and 39.2 µmol/min for colloidal chitin, respectively. The enzyme was found stable in a range of pH (5.0–10.0), high NaCl concentration (5 M) and at 50 °C temperature. It showed optimal activity at pH 7.0 and 40 °C temperature and contains 52.9% α-helix, 21.5% β-pleated sheet and 10.1% turn in this condition. The enzyme is not a metallo-enzyme, inhibited by Hg2+, marginally activated by Tween 60, Tween 80 and SDS (at 1% level), and reasonably stable in presence of DMSO, β-mercaptoethanol, PMSF, sodium azide. The stability of the chitinase at varied conditions assures its employment in industrial sectors.