SELECTION OF MEDIUM FOR BIOPESTICIDES FERMENTATION PROCESS BY Bacillus subtilis AAF2 UAAC 20701

Abstract

Selection of the optimum medium type for biopesticide fermentation process by endophytic bacteria Bacillus subtilis AAF2 UAAC 20701 has been done. The medium type used were: Tryptic Soy Broth (TSB) medium, Luria Bertani (LB), Glucose Soybean Flour medium, and modified corn immersion. Erlenmeyer flask containing the medium to be used in the fermentation process. Then it was incubated at 27⁰C with agitation of 120 rpm. Next step, inoculum was inoculated as much as 10% (v/v) into Erlenmeyer containing the fermentation medium and incubated at 27⁰C with 120 rpm agitation. The parameters measured were pH fluctuation, bacterial cell count, growth inhibition zone of test bacteria and fungal growth inhibition measured every 24 hours for 72 hours. The results showed that the best fermentation condition for producing the highest biopesticide activity using Bacillus subtilis AAF2 UAAC 2070 from four type of testing medium was found in Corn Immersion Medium. The inhibition zone towards Ralstonia solanacearum and Xanthomonas campestris wth inhibition towards Fusarium oxysporum was 64.3% while towards Schlerotium rolfsii was 67.1 % with 48 hours of incubation time and pH changes during fermentation range from 7.0 to 7.8.