Abstract

CASTRO, Rocío et al. Characterization of a extracellular chitinase produced by Serratia sp. BIOMI-363706 using colloidal chitin as substrate. Rev. Soc. Quím. Perú [online]. 2011, vol.77, n.2, pp.101-108. ISSN 1810-634X.

Chitinase is an enzyme able to hydrolyze chitin into its oligo and monomeric components. The chitin-oligosacharids, the acetylchitobiose dimer and the acetylglucosamine monomers are very important to industry due their wide range of medical, agricultural and industrial applications. In the present report was made the characterization of an extracellular chitinolitic enzyme obtained from BIOMI-363706 bacterial isolate, molecularly characterized as Serratia sp. This bacterium uses colloidal chitin as unique carbon and nitrogen source. While inoculated into a media containing 2% colloidal chitin (QC), 0,1% K₂HPO₄ and 0,05% MgSO₄.7H₂O, at pH 7,2, the bacteria yields optimally extracellular chitinase after incubation along 72 hours at 37 ºC. Optimal temperature, pH as well as thermostability of the enzyme were 50 ºC, pH 6,5 and < 70 ºC. Chitinase was activated by Mn⁺² y Co⁺². Activity upon different subtracts was according the following order: Colloidal chitin > chitin powder (< 1mm) > glycol-chitin. The enzyme showed a Vmax value of 0,015 mol/min and a Km of 1,278 mg/ml, using colloidal chitin as substrate. The studied enzyme shown, as one of their characteristics, an thermostability that can be an advantage in order to maximize the reactions at industrial scales that improve and potentiate the enzymatic chitin degradation.

Keywords : Colloidal chitin; N-acetylglucosamine; chitinase activity.

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