Antagonistic bioactivity of endophytic strains isolated from Salvia miltiorrhiza
The antibiotic-producing potential of endophytic populations from medical plant of Salvia miltiorrhiza was examined. A total of 63 isolates was screened against five fungal and three bacterial species for the production of antimicrobial compounds. It showed that more isolates was antagonistic to fungi than to bacteria. One bacterial isolate named DX30 showed broad-spectrum of antagonistic activity against all the target organisms in plate assays. Morphology, physiological, chemical characteristics and 16S rRNA gene sequence analysis of strain DX30 demonstrated that it belonged to the genus Bacillus. The strain DX30 had maximum activity at temperature of 25°C and pH of 6.0 respectively and remained stable activity at temperature between 30 and 100°C and pH between 6 and 12. Strain DX30 seems promising in the biological control.
Key words: Endophytes, antimicrobial bioactivity, 16S rRNA gene, Salvia miltiorrhiza.