[Isolation, purification and characterization of antifungal protein from rice endophytic bacterim Bacillus subtilis G87].

In order to obtain the antagonistic protein of Bacillus subtilis G87 and definitude its characterization.Methods of ammonium sulfate precipitating and column chromatography analyzing were used to isolate and purify the protein.A purified protein (peak 6-2-1) was obtained which molecular weight was 50.8 kD by SDS-PAGE and isoelectric point was 5.90 by IEF-PAGE. The antifungal protein contained 0.62% saccharide and some proline or hydroxyproline, but no lipid and aromatic amino acid. The inhibitory activity of the antifungal protein would decreased distinctly at the higher temperature (> or = 60 degrees C) and in the condition of alkalinity (pH > 8), but tolerant to ultraviolet radiation, chloroform, trypsin, proteinase K and pepsin.Antifungal protein of Bacillus subtilis G87 was a kind of glycoprotein without aromatic hydrocarbon. It was sensitive to higher temperature and tight alkalinity but not to proteinase analog and ultraviolet radiation et al.