具抑菌活性杉木内生菌的分离、鉴定及培养条件优化

Identification of an Endophytic Bacterium Having Antagonistic Activity Isolated from Cunninghamia lanceolata and Optimization of Fermentation Condition

从杉木根部分离获得一株具部分拮抗活性的内生细菌,通过生理生化、菌株形态及16S r DNA序列同源性分析对菌株进行了鉴定,并对不同培养条件下其发酵粗提物的抑菌活性进行了考察,确定了最佳培养条件。结果表明,所获菌株属于芽孢杆菌属(登录号:KC257097),命名为SM-8;其发酵粗提液对金黄色葡萄球菌、大肠杆菌具有较强的抑制效果;确定最佳培养条件为蔗糖(2%)、蛋白胨(1%)、p H 6.0、30℃。Bacillus sp.SM-8的分离及培养条件的优化,为进一步富集、分离代谢活性物质的工作奠定了基础。

An endophy tic bacterium strain with certain antagonistic activity was isolated from the root of Cunninghamia lanceolata. The strain was identified by physiological and biochemical experiments, morphological characteristics and 16 S r DNA sequence homology analysis. The antagonistic activity of fermentation extract under different conditions was investigated and the culture conditions of the strain were optimized. The results show that the strain belongs to Bacillus, the registration number is KC257097, named SM-8. The strain SM-8 exhibited the highest antibacterial activity against Escherichia coli. and Staphylococcus aureus. The optimal culture condition is growth in a medium with sucrose(2%), peptone(1%), initial p H 6.0, at 30℃. The isolation of the Bacillus sp. SM-8and the optimization of its culture condition laid the foundation of further concentration and separation of the metabolic activity substance.