Artículos de revistas
Production, characterization and purification of chitosanase from Bacillus cereus
Registro en:
Brazilian Journal of Chemical Engineering. Brazilian Society of Chemical Engineering, v. 16, n. 2, p. 185-192, 1999.
0104-6632
S0104-66321999000200011
10.1590/S0104-66321999000200011
Autor
PIZA, F. A. T.
SILOTO, A. P.
CARVALHO, C. V.
FRANCO, T.T.
Institución
Resumen
A culture medium for a wild strain of Bacillus cereus was developed for chitosanase production by using an experimental design. The factors having the strongest influence on chitosanase production were ammonium sulfate concentration, aeration, pH and the interaction between the first two parameters. Optimal conditions for chitosan hydrolysis were pH 5.8 and 54 oC; however, hydrolysis activity drastically decreased at pH 7.0. The enzyme was purified (single-electrophoretic band) by partitioning in an aqueous two-phase system (ATPS), followed by cation-exchange chromatography with a 66% yield. Chitosanase was mainly collected in the top phase (K = 129) of a 22% PEG 1,500, 13% phosphate (pH = 5.8) and 12% NaCl (w/w) solution, and the main protein contaminants were evenly distributed between the phases (K = 1.07). The apparent molecular weight and the isoelectric point of the chitosanase, determined by SDS-PAGE electrophoresis and by isoelectric focalization, were 47 kDa and 8.8, respectively. 185 192 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)