Abstract:The antibacterial activity of actinomycete JSD-1 was preliminarily investigated in this work, and the fermentation conditions that affected its antibacterial activity were optimized to enhance the antibacterial effect. Using pathogenic Escherichia coli and Staphylococcus aureus as indicator bacterias, the antibacterial activity of strain JSD-1 was investigated by dilution coating, agar diffusion method and liquid co-culture method. The fermentation conditions of JSD-1 were optimized by single factor experiment and orthogonal experiment design. The optimized culture medium to affect the antibacterial activity of JSD-1 was composed of glucose 10 g/L，urea 2.5 g/L. The optimal fermentation condition was as follow: culture temperature of 35 ℃ pH 7.0, inoculation amount 3%, culture time 7 d. The antibacterial activity of JSD-1 was significantly improved. The inhibitory zone diameter increased from 10.08 mm to 18.63 mm, which was beneficial to the further development and utilization of JSD-1 as an antagonist. It was found that the growth and proliferation of pathogenic Escherichia coli and Staphylococcus aureus were inhibited by JSD-1 in their logarithmic phase, stable phase and decline phase continuously, indicating that JSD-1 had great antibacterial potential and could be used as a candidate strain for biocontrol preparation.
