Optimization of Fermentation Conditions of an Endophytic Actinomycetes from Tobacco Plant

In order to increase the yield of the antibacterial substance produced by an endophytic actinomycetes,Y12,from tobacco plant in the process of fermentation,a series of orthogonal experiments on Y12 were carried out in the shaking flasks to obtain optimal components of the fermentation media as well as the fermentation conditions.It was concluded that the optimal proportion of the fermentation medium was: 1.5% soybean flour,1.5% peptone,1.5% glucose,1.5% soluble starch,0.05% MgSO4.7H2O,0.25%(NH4)SO4,0.4% NaCl,0.1% KH2PO4 and 0.5% CaCO3.The optimal fermentation conditions were: Medium’ s initial pH value 7.5,fermentation temperature 30 ℃,and fermentation time 72 hours.It was observed from the experiments that the inhibition diameters of the zymotic fluid increased by 44.9% under the optimized conditions.