Abstract:
R. pickettii TT47 (isolate TT47) were selected isolate having the potency of strong inhibition to the
growth of R. solani in vitro and suppress the development of rice sheath blight disease in vivo.
The antifungal activity test of the filtrate from fermentation broth of the isolate showed that the
growth of R. solani reduced significantly. Presumably the culture broth of the isolate contains
antifungal bioactive compounds. Antifungal activity in the culture broth of the isolate was
significantly correlated with the cell growth of the isolate. Antifungal bioactive compounds were
successfully extracted using buthanol or hexane solution for TT47 isolate.. MIC of TT47-hexana
extract was 0,1 mg/l, and the extract was not phythotoxic against the rice seed. Stability of the
active metabolites in filtrate broth cultured isolate was relatively stable on pH range from acidic to
basic (pH 4, 7, and 10) but was sensitive to temperature.
