Optimization of fermentation conditions of Streptomyces albus NB8 against the growth of Phytophthora infestans

In order to enhance the inhibitory effect of substances in fermentation liquid of Streptomyces albus NB8 strain against the growth of Phytophthora infestans,the fermentation conditions of NB8 strain were investigated by single-factor experiment.The results showed that optimal fermentation conditions were as follows:seed liquid cultured in Gause 1 medium after 5 d was inoculated with a volume of 125 mL/250 mL and amount of 1.5% into same medium,then was cultured 10 d as the initial pH7.0,34 ℃,50 r/min,12 h dark/12 h light.And the inhibitory rate reached 81% under the optimal fermentation conditions,which increased by 20% in comparison with pre-optimization.The findings indicate that NB8 strain has a great potential in control potato late blight in future.