高寒草甸根围拮抗芽孢杆菌筛选鉴定及脂肽化合物分析

Screening and Identification of Bio-control Bacillus Strains Isolated from Rhizosphere of Altiplaino Meadow and Its Lipopeptide Compounds

本研究通过平板对峙法分别从青海日月山及达日地区高寒草甸根围分离菌株中筛选到8株对油菜菌核病菌Sclerotinia sclerotiorum及水稻白叶枯病菌Xanthomonas oryzae pv.oryzae均具有明显拮抗效果的芽孢杆菌菌株RYS41、RYS42、RYS43、RYS44、DR1、DR2、DR3及DR20。生理生化、脂肪酸甲脂、16S rDNA及gyrB基因测序等分析结果表明,菌株RYS41、RYS42、RYS43、RYS44为解淀粉芽孢杆菌Bacillusamyloliquefaciens;菌株DR1、DR2、DR3、DR20鉴定为短小芽孢杆菌B.pumilus。MALDI-TOF-MS质谱分析结果表明,菌株RYS41产生脂肽类化合物Surfactin、Bacillomycins D和Fengycin,菌株DR20产生脂肽类化合物Surfactin、IturinA和Fengycin,推断可能与对油菜菌核菌及水稻白叶枯病菌的拮抗作用有关。

Eight biocontrol Bacillus strains, RYS41, RYS42, RYS43, RYS44, DR1, DR2, DR3 and DR20, were selectied via dual culture method from the isolates obtained from altiplaino meadow rhizosphere of Riyue mountain and Dari region in Qinghai province. The selected isolates were highly antagonistic against Sclerotinia sclerotiorum and Xanthomonas oryzae pv. oryzae. Assays on their biochemical characteristicss, fatty acid methyl ester （FAME）, 16S rDNA sequence and gyrB sequence indicated that strains RYS41, R~$42, R~$43 and R~$44 were B. amyloliquefaciens, and strains DR1, DR2, DR3 and DR20 were B. pumilus, Lipopeptide compound analysis via MALDI-TOF-MS showed that strain RYS41 produced Surfactin, Bacillomycins D and Fengycin, while strain DR20 produced Surfactin, IturinA and Fengycin, which is probably related with biocontrol efficacy of the strains againist diseases.