Purification and characterization of an extracellular chitinase from the entomopathogen Metarhizium anisopliae

Chitinases are produced by Metarhizium anisopliae when it is grown in the presence of chitin. A chitinase from the culture filtrate of Metarhizium anisopliae was successively purified by precipitation with ammonium sulphate, followed by anion-exchange chromatography on DEAE-Sephacel. The purified enzyme, which has a molecular mass of approximately 30 kDa by sodium dodecyl sulphate - polyacrylamide gel electrophoresis, catalyses the hydrolysis of p-nitrophenyl beta-N-diacetylchitobiose with an apparent K-m of 0.537 mmol and V-max of 4.86 nmol.mL(-1).min(-1). The optimum pH and temperature were 4.5-5.0 and 40-45 degrees C, respectively.