抗烟草青枯菌菌株的分离、鉴定和发酵条件研究

Isolation and Identification of Antagonistic Strains Against Ralstonia Solancearum and Optimization of the Fermentation Conditions

烟草青枯病是一种全球性的土传性病害,其危害严重,每年都给烟草行业带来巨大的损失.筛选对烟草青枯病的致病菌青枯劳尔氏菌有较好拮抗作用的菌株,用分子生物学方法鉴定其种属,并对拮抗菌株的发酵条件进行初步研究,为烟草青枯病生物防治奠定基础.测试菌共246株,来自从土壤样品中分离得到的155株菌株和实验室保藏91株.以强致病青枯菌为测试菌,用双层平板法筛选得到2株拮抗菌.16SrDNA序列分析表明,这两株分别为娄彻氏链霉菌和短小芽孢杆菌.对活性较好的链霉菌开展进一步的发酵条件研究,初步获得活性最佳的发酵条件和生物量最大的培养条件.为防治烟草青枯病提供了新的菌株.

Tobacco bacterial wilt is a diverse soil-borne disease with a wide host range and it causes huge losses to the tobacco industry every year .The objective of this study was to isolate strains that exhibit high and stable levels of biocontrol efficacy ,identify them by molecular biological methods and optimize the fer-mentation conditions so as to lay a foundation for biological control of this tobacco disease .A total of 246 strains were tested by the double-plate method ,of which 155 were isolated from the soil and 91 were main-tained in our lab .Only two strains exhibited a strong and stable activity against the plant pathogen Ralsto-nia solanacearum .BLAST analysis of 16S rDNA sequences indicated that one strain was Streptomyces ro-chei and the other was Brevibacillus sp .Finally we preliminarily obtained the best fermentation conditions for inhibitory effect and biomass by investigating S. rochei fermentated in different conditions .