中文摘要：

从山西太谷、运城采集的油菜中分离得到40株植物内生细菌,经过初步筛选得到具有生防潜力的菌株yc8,经鉴定为环状芽孢杆菌（B.circulans）。采用正交试验设计对油菜内生细菌yc8进行营养配方和发酵条件的系统研究。通过yc8发酵液中细菌浓度、拮抗物质质量浓度和yc8发酵液对油菜菌核病[Sclerotinia sclerotio-rum（Lib.）de Bary]的抑菌作用综合评定,得到优化配方为：麦芽糖（30g/L）、牛肉膏（50g/L）、酵母粉（7g/L）、MnSO4（2g/L）、FeSO4（1g/L）、ZnSO4（2g/L）、CaSO4（2g/L）、CuSO4（2g/L）、K2HPO4（2g/L）、KAl（SO4）2（1g/L）、发酵温度28℃、装液量40%、摇床转数150r/min、发酵液pH=7.5,使环状芽孢杆菌在摇瓶发酵条件产生拮抗物质质量浓度达到为725.1μg/mL和对油菜菌核病茵的平板抑菌率达到85.3%。

英文摘要：

Forty endophytic bacterium strains were isolated from rape which were collected from Taigu and Yuncheng County in Shanxi Province in P.R.China. Inhibitory activity of yc8 was obvious in the primary antagonistic screening experiment and the fermentation condition was studied,it was characterized to be B.circulans. This experiment which took different kinds of carbon source and nitrogen source,different concentrations of yeast powder and metal ion and fermentation condition as the basic factor,adopted orthogonal experimental design to test. Then,the optimized formula was selected by the comparison of bacterial concentration of yc8,the antagonistic substance concentration of yc8 production and the inhibitory activity of yc8 to Sclerotinia sclerotiorum （Lib.） de Bary. The result indicated the fermentation conditions were malt sugar（30 g/L）,beef extract（50 g/L）,yeast powder（7 g/L）,MnSO4（2 g/L）,FeSO4（1 g/L）,ZnSO4（2 g/L）,CaSO4（2 g/L）,CuSO4（2 g/L）,K2HPO4（2 g/L）,KAl（SO4）2（1 g/L）,fermentation temperature 28 ℃,the content of fermentation fluid 40%,the rotational speed of shaker 150 r/min,pH=7.5,under which the concentration of the antagonistic substances produced by B.circulans reached 725.1μg/mL and had strong inhibitory activity against Sclertinia sclerotiorum（Lib.） de Bary.