拮抗菌B-FS06的鉴定及其发酵产物对黄曲霉的抑制作用

Identification of B-FS06 and the Antagonistic Activity of Its Cultural Productions against Aspergillus flavus

从油菜地分离到一株细菌B-FS06,其表现出对黄曲霉的拮抗作用。根据该细菌的理化性质、微观结构及16S rDNA序列的进化树分析,鉴定菌株B-FS06为枯草芽孢杆菌。细菌发酵液经20%、40%、60%、80%硫酸铵饱和度分级沉淀均表现出抑制黄曲霉活性。采用96孔板法测得该菌胞外蛋白粗提液对黄曲霉的最低抑菌浓度为31.2μg/ml。蛋白粗提液经121℃高压灭菌20min后对黄曲霉抑制率为91.3%。

B-FS06 isolated from the rape field was showed to be antagonistic against Aspergillus flavus, and was identified as Bacillus subtilis according to the physiological and biochemical properties, microstructure and the phylogenetic analysis of the 16S rDNA. The antifungal activity against A. flavus was found in each fraction of extracellular crude protein extract （CPE） obtained from precipitation separation with 20 %, 40 %, 60 %, 80 % ammonium sulfate. Assay using 96-well plate illustrated that the minimum inhibitor concentration （MIC） of the CPE against A. flavus was 31.2 μg/ml. After treatment at 121 ℃ for 20 min, the CPE gave 91.1% inhibition of growth against A. flavus.