Purification and characterization of an exochitinase from Bacillus thuringiensis subsp. aizawai and its action against phytopathogenic fungi
2006; Canadian Science Publishing; Volume: 52; Issue: 7 Linguagem: Inglês
10.1139/w06-019
ISSN1480-3275
AutoresLuis Morales de la Vega, José E. Barboza‐Corona, María Guadalupe Aguilar‐Uscanga, Mario Ramírez‐Lepe,
Tópico(s)Phytase and its Applications
ResumoA chitinolytic enzyme from Bacillus thuringiensis subsp. aizawai has been purified and its molecular mass was estimated ca. 66 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme was able to hydrolyze chitin to chitobiosides but not carboxymethylcellulose, cellulose, pullulan, and laminarin. Optimal pH and temperature were detected at 6 and 50 degrees C, respectively. Stability, in the absence of substrate, was observed at temperatures less than 60 degrees C and pH between 5 and 8. Enzyme activity was significantly inhibited by K+ and EDTA and completely inhibited by Hg2+. Purified chitinase showed lytic activity against cell walls from six phytopathogenic fungi and inhibited the mycelial growth of both Fusarium sp. and Sclerotium rolfsii. The biocontrol efficacy of the enzyme was tested in the protection of bean seeds infested with six phytopathogenic fungi.
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