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

Abstract:

Abstract: [Objective] In order to obtain the antagonistic protein of Bacillus subtilis G87 and definitude its characterization. [Methods] Methods of ammonium sulfate precipitating and column chromatography analyzing were used to isolate and purify the protein. [Results] A purified protein (peak 6-2-1) was obtained which molecular weight was 50.8kD 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 (≥60℃) and in the condition of alkalinity (pH>8), but tolerant to ultraviolet radiation, chloroform, trypsin, proteinase K and pepsin. [Conclusion] 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.