Isolation of endophytic bacteria from medicinal plant Brucea javanica L. Merr. and its antifungal activity

ObjectiveEndophytic bacteria with antagonistic activity were isolated from medicinal plant Brucea javanica L. Merr. to provide references for developing new biological fungicides. MethodThe endophytic bacteria were isolated by tis-sue homogenization and the strains with antifungal activity were screened by in vitro and in vivo antifungal tests. The strains with stronger inhibitory activity was identified based on morphology, physiological and biochemical characteristics, 16S rDNA sequence analysis and Biolog test. ResultThere were 43, 19, 15 and 8 isolates obtained from root, leaf, stem and fruit of Brucea javanica, respectively. Especially, the strain YGB-11 isolated from root showed good antibiosis characteristics with antibacterial rate over 80.00%to Penicillium digitatum (pers.ex Fr.)Sacc of Citrus green mold and Helminthosporium torulosum (Syd.) Ashby of banana helminthosporium leaf spot. Based on morphological, physiological and biochemical characteristics, 16S rDNA sequence analysis and Biolog test, the strain YGB-11 was identified as Bacillus amyloliquefacien. ConclusionWith wide antimicrobial spectrum and high antifungal activities, YGB-11 has promising prospects.