Isolation and identification of endophytic bacterial strain LYM3 from Rauvolfia vomitoria and its fermentation conditions optimization for production of antibacterial substance

Strain LYM3, isolated from Rauvolfia vomitoria Afzel, had higher antagonistic effect against Colletotrichum musae, and its antagonistic activity was 64% in plate. According to its morphological characteristics, and 16S rDNA sequence analysis, the strain LYM3 was identified as Bacillus subtilis. Using single-factor method袁 the fermentation conditions of its antibacterial substance production were optimized. The optimal medium contained 2% soluble starch, 1% tryptone, 0.8% yeast extract, 1% NaCl, and initial pH was 6. After 60 h culture at 28益, 180 r/min, the antibacterial substance had higher yield, and the diameter of inhibition zone was up to 3.42 cm