Abstract:

One endophytic bacteria G23 strain which could significantly inhibit some Phytopath-ogenic fungi was isolated from xylem of apple. In order to clarify the taxonomic status and the antifungal activity, the morphology, physiological, biochemical characteristics and 16S rDNA sequence analysis were used to identify the taxonomic status. The fermentation liquid passed the filter and high-temperature process, and the types of antimicrobial substances were analyzed. The results showed that this strain was identified as Bacillus subtilis. The inhibition rate of its filtration ranged from 63.4% to 87.5% on 8 kinds of pathogens, but it decreased and inhibitory rate ranged from 57.4% to 79.6% after the treatment of high temperature. Thus, it confirmed that this strain could secrete various antagonistic substances included temperature-insensitive antibiotic as well as temperature-sensitive peptides and protease.