拮抗黄曲霉的伯克霍尔德菌的筛选、鉴定及应用

Screening, identification and application of Burkholderia antagonizing Aspergillus flavus

中文关键词:  黄曲霉  花生  拮抗菌  分离鉴定  伯克霍尔德菌

英文关键词:Aspergillus flavus  peanut  antagonism  isolation and identification  Burkholderia

中文摘要:

      目的 筛选一株能拮抗黄曲霉生长的菌株, 并进行菌株鉴定、应用研究和基因初步分析。方法 以费县花生地土壤的微生物为研究对象, 通过黄曲霉对峙试验筛选得到有效菌; 通过形态学观察和16S rRNA基因分析、鉴定确定有效菌种类; 黄曲霉孢子悬浮液侵染花生荚果和花生籽仁, 验证有效菌拮抗黄曲霉生长的效果; 分析菌株的基因组特征和次生代谢产物合成基因簇, 确定有效菌株的基本特性。结果 筛选获得能拮抗黄曲霉生长的有效菌株G22。通过形态学特征和基因同源性分析, 鉴定菌株G22为伯克霍尔德菌(Burkholderia latens), 同源性达99.93%, 命名为伯克霍尔德菌G22。有效菌株的发酵液对花生荚果和花生籽仁上黄曲霉的生长有一定拮抗作用。有效菌株的基因组有3个染色体和1个质粒, 次生代谢产物合成基因簇证明有效菌株有拮抗特性。结论 菌株G22对黄曲霉生长具有良好的拮抗作用。菌株G22的花生应用效果研究具有重要的实践意义, 为下一步开发黄曲霉的微生物菌剂奠定了基础。

英文摘要:

      Objective To screen a strain that can antagonize the growth of Aspergillus flavus and to identify the strain, study its application and analysis its genetic preliminarily. Methods The microorganisms in the soil of peanut field in Feixian County were used as the research object, and the effective strains were obtained through the screening of Aspergillus flavus standoff test; the effective strains species were determined through morphological observation and 16S rRNA gene analysis and identification; the peanut pods and peanut kernels were infested with the suspension of Aspergillus flavus spores to validate the effective bacteria’s effect of antagonizing the growth of Aspergillus flavus; and the genome characteristics of the bacterial strains and the clusters of genes of secondary metabolites synthesis were analyzed to determine the basic characteristics of the effective bacterial strains. The genomic characteristics of the strain and the secondary metabolite synthesis gene cluster were analyzed to determine the basic characteristics of the effective strain. Results Effective strain G22, which could antagonize the growth of Aspergillus flavus, was obtained by screening. The strain G22 was identified as Burkholderia latens with 99.93% homology and named Burkholderia latens G22 by morphological characterization and gene homology analysis. The fermentation broth of the effective strain had a certain antagonistic effect on the growth of Aspergillus flavus on peanut pods and peanut seed kernels. The genome of the effective strain had 3 chromosomes and 1 plasmid, and the secondary metabolite synthesis gene cluster proved that the effective strain had antagonistic properties. Conclusion Strain G22 has good antagonistic effect on the growth of Aspergillus flavus. The application effect of strain G22 in peanut has important research significance in practice, which will lay a foundation for the further development of microbial fungicides for Aspergillus flavus.