杨树烂皮病拮抗细菌鉴定及无菌滤液抑菌效果研究

Identification of Antagonistic Bacteria Against Poplar Skin Rot and Study on the Antibacterial Effect of Sterile Filtrate

杨树烂皮病是威胁我国三北防护林安全的杨树主要病害之一。生防菌株SF3是本实验室采用平板稀释法从杨树根围土壤中分离的一株对杨树烂皮病菌有抑制效果的细菌,平板对峙法显示:菌株SF3及细菌滤液对杨树烂皮病菌抑菌率达76%(7d);通过菌株形态学特征、生理生化特征和16SrDNA序列分析鉴定该菌株为贝莱斯芽孢杆菌(Bacillus velezensis),其最佳发酵条件为pH7~8、菌株年龄4d、温度20~30℃、发酵时间为3~4.5d,细菌滤液不耐酸碱,不耐高温。贝莱斯芽孢杆菌SF3有较强的抑菌活性,具有较高的工业开发和田间应用的前景。

Poplar bark rot is one of the main poplar diseases threatening the safety of Three-North Shelterbelt Program in China.The biocontrol bacterial strain SF3 was isolated from the soil around the roots of poplar tree using a plate dilution method in our laboratory.The plate test showed that the bacterial strain SF3 and bacterial filtrate had a 76%(7d)inhibition rate against the pathogen;The strain was identified as Bacillus velezensis based on its morphological,physiological and biochemical characteristics,and 16S rDNA sequence analysis.The optimal fermentation conditions were pH 7~8,strain age 4 days,temperature 20~30℃,and fermentation time 3~4 days.The bacterial filtrate was not resistant to acid,alkali,or high temperature.Bacillus velezensis SF3 has strong antibacterial activity and has high prospects for industrial development and field application.