Optimization of Fermentation Conditions for Antibiotic Production by Actinomycetes YJ1 Strain against Sclerotinia sclerotiorum

Abstract

In order to improve the productivity of activities substance of actinomycetes YJ1, the effects of the medium components, inoculation volume, medium capacity, rotary speed, fermentation time, temperature and initial pH on the biological activity of YJ1 were investigated by detecting the mycelium growth inhibition rate of Sclerotinia sclerotiorum. The results show that the inhibition rate is the highest under the optimum medium composition (g/L), containing sucrose 10.0, soluble starch 10.0, soybean meal 20.0, K 2 HPO 4 0.5, MgSO 4 0.5, NaCl 1.0 and FeSO 4 0.01. The maximum antibiotic activity is obtained at the inoculation volume 5%, medium volume in 250 ml flask 75 ml, rotary speed of 180 r/min, fermentation time 4 days, temperature 28°C and initial pH 7.0. The inhibition rate has been increased by 6.71% under the optimized condition.