Optimizing Fermentation Condition for Endophytic Brevibacillus brevis W4 Strain Against Tomato Botrytis cinerea
YANG Cong-jun
（College of Plant Health and Medicine，Qingdao Agricultural University，Key Lab of Integrated Crop Pest Management of
Shandong Province，Qingdao 266109，Shandong，China）
To improve the activity of fermentation liquor from endophytic Brevibacillus brevis W4 against Botrytis cinerea，fermentation medium and conditions were optimized by single factor and orthogonal test
design．The results showed that the optimal fermentation medium components were as following peptone 2.0%，
fructose 1%，NaCl 0.25%．The optimal fermentation conditions were pH 8.0，seed age 20 hours，inoculum
size 5%，loaded liquid 50 mL，fermentation temperature 35 ℃，shaker speed 150 r·min-1，fermentation time
24 hours．The inhibitory rate of 25 times diluent of fermentation liquor on B. cinerea was 92.8%，increasing
26.9 percentage point compared with that without optimization．The activity of fermentation filtrate from W4
strain was significantly improved by optimizing the medium and fermentation conditions．These results have
laid a foundation for further extraction and seperation of active ingredients against tomato B. cinerea．
