SCREENING OF ENDOPHYTIC BACTERIA PRODUCING ANTIFUNGAL ISOLATED FROM INDONESIA MEDICINAL PLANT, JAVA GINSENG (TALINUM TRIANGULARE) (JACQ.) WILLD

Abstract

Objective: The objective of this research was to isolate and characterize endophytic bacteria from Talinum triangulare having antifungal activity.Methods: The endophytic bacteria were isolated from roots tissue of Talinum triangulare by surface sterilization method. The isolates were cultured in Trypticase Soybean agar and antagonist activities were evaluated by dual culture assay against Fusarium oxysporum, Trichoderma reesei and Candida albicans. For metabolite antifungal activities, bacterial isolates were grown for 4 d in TS broth at 35 °C under shaking condition. The antifungal activities of the supernatant extract were determined by using the disk agar diffusion. Polyketide synthase (PKS I) and NRPS genes fragments of all isolates were amplified.Results: The result reveals that 4 of 23 endophytic bacterial isolates demonstrated great antifungal potentiality against many tested fungi. Polyketide synthase (PKS I) and NRPS genes amplification were showed 10 and 4 of endophytic isolates detected harboring PKS type I and NRPS genes, respectively. In general, high frequencies of positive PCR amplification were obtained for PKS I (43.47%). Phylogenetic analyses based on the 16S rRNA gene sequence, morphological, physiological and biochemical showed that the isolates were identified as a member of genus Bacillus and Brevibacillus.Conclusion: These results indicated that the endophytic bacteria from java ginseng could be used as an alternative source of antifungal agents.