Abstract
An antifungal substance in the culture supernatant of Bacillus sp. bacteria seems to be water-soluble and acidic polypeptide. The antifungal activity was retained after the culture supernatant was heated at 121°C for 15min. Crude powder having an antifungal activity was obtained by both acidification and ammonium sulfate fractionation of the culture supernatant. The crude powder was loaded onto a DEAF-cellulose column and the column was eluted with a stepwise manner by raising the sodium chloride concentration in 50mM phosphate buffer (pH 6.8): 0.3M, 0.4M, 0.5M, 0.6M, 0.7M and 0.8M. Among them, fractions of F-II, F-III and F-IV eluted with 0.4M, 0.5M and 0.6M sodium chloride, respectively, were purified by gel filtration of Sephadex G-100. The purified powder showed a strong antifungal activity to Helminthosporium oryzae and Pyricularia oryzae which were used as the test organisms.
