抗烟草花叶病毒(TMV)生防菌的鉴定及其发酵条件优化

Identification and optimization of biological bacteria against tobacco mosaic virus(TMV) through fermentation

为有效防治烟草普通花叶病毒病(TMV),从土壤中分离筛选到1株抗TMV的细菌菌株Z5,经形态学、生理生化和分子生物学鉴定为贝莱斯芽胞杆菌(Bacillus velezensis),该菌培养液对TMV体外抑制率达到96.40%,田间小区试验对烟草普通花叶病毒病的防效为50.43%。通过单因素法优化Z5发酵体系,最适培养基为NB培养基,葡萄糖、酵母膏分别作为碳源和氮源,最优发酵条件为初始pH 7.0、装液量100 mL/250 mL、28℃发酵60~72 h,优化后Z5菌数增加44.38%且发酵液对TMV抑制效果稳定,抑制率达到98.71%。

In order to effectively prevent and control the disease caused by common tobacco mosaic virus(TMV), a bacterium strain, Z5, resistant to TMV was isolated from soil and was identified as Bacillus velezensis through morphological, physiological, biochemical and molecular biological tests.The culture solution of this bacterium had an in vitro inhibition rate against TMV up to 96.40% and a control effect of 50.43% on TMV in field plot experiments. After the optimization of fermentation condition through a single factor experiment, the optimal medium for strain Z5 was NB medium with glucose and yeast extract as carbon and nitrogen sources respectively, and the optimum conditions were initial pH 7.0, medium volume 100 mL/250 mL and fermentation at 28 ℃ for 60-72 h. Under the optimized condition, the bacterial count increased by 44.38% and the fermentation broth had a stable inhibitory effect against TMV with an inhibition rate of 98.71%.