青海柴达木极端干旱沙地分离芽孢杆菌的分子鉴定及拮抗活性分析

Molecular identification of Bacillus strains isolated from extreme dry-sand environment in Qinghai Chaidamu region and its lipopeptide compound analysis

【目的】研究高原极地环境微生物资源。【方法】采用rep-PCR指纹图谱分析、gyrB基因及16S rDNA基因序列分析等多项分子鉴定技术对分离自青海柴达木极端干旱沙地的8株芽孢杆菌菌株进行分类鉴定;通过平板对峙及接种离体叶片试验检测分离菌株的拮抗活性及对病原菌侵染的防效;采用MALDI-TOF-MS质谱分析生防菌株的活性成分。【结果】8株分离菌株鉴定为Bacillus amyloliquefaciens(6株)、Bacillus axarquiensis(1株)和Bacillus atrophaeus(1株);各菌株对油菜菌核病原真菌(Sclerotinia sclerotiorum)均具有显著的拮抗活性;接种离体叶片试验表明菌株对油菜菌核病菌的侵染具有较好防效;MALDI-TOF-MS质谱分析结果显示菌株DGL1(B.amyloliquefaciens)产生脂肽化合物Fengycin,菌株DGL6(B.axarquiensis)产生脂肽化合物Surfactin、BacillomycinsD和Fengycin,菌株DCD1(B.atrophaeus)产生脂肽化合物Surfactin、Fengycin。【结论】为高原干旱沙地极端环境微生物资源研究及生防菌资源开发和应用提供了研究材料。

[Objective] Microbe resource research in extreme environment. JMethods] Eight Bacillus strains isolated from Chaidamu extreme dry-sand region in Qinghai Province, were identified by polyphasic molecular taxonomy methods including rep-PCR （BOX-PCR and ERIC-PCR） fingerprints, as well as gyrB and 16S rDNA partial sequence analysis. Antagonis- tic activity detection and dual culture method screening were used to check antagonistic activ- ity and bio-control efficacy of isolates. MALDI-TOF-MS were used to analyze lipopeptide compound of strains. [Results] Eight isolates were identified as Bacillus amyloliquefaciens （6 isolates）, Bacillus axarquiensis （1 isolate）, Bacillus atrophaeus （1 isolate）. All of the isolates presented distinct antagonistic activity and bio-control efficacy to Sclerotinia sclerotiorum. MALDI-TOF-MS results showed that the strain DGL1 （B. amyloliquefaciens） produced Fen- gycin, strain DGL6 （B. axarquiensis）produced Surfactin, BacillomycinsD and Fengycin, while strain DCD1 （B. atrophaeus） produced Surfactin and Fengycin. [Conclusion] The research provided Bacillus resources for further developing and application of bio-control strains ad- justing in dry-sand extreme environment of Qing-Tibet Altiplano.