Optimization of fermentation conditions by mangrove actinomycete strain G15 with antibacterial activity

G15 was isolated from mangrove sediments in ShangKou GuangXi,which showed higher antibacterial activity.Using Staphylococcus aureus as a indicator,the fermentation conditions of G15 were studied to improve the productivity of antibacterial compounds.The optimum fermentation medium were determined by single-factor experiments as follows: soluble starch 20g,yeast powder 15g,NaCl 30g,distilled water 1000ml,and best fermentation conditions containing inoculum size 15%,liquid volume 30%,Fermentation time 168h and the initial value pH value 7.5.Under the optimum mediums and the best fermentation conditions,the yield of antibacterial compounds is 3 fold of the past.