Zhongguo youzhi (Feb 2024)
一株防治花生采后黄曲霉污染的拮抗菌的 筛选及其防控效果Screening of biocontrol bacteria against peanut postharvest Aspergillus flavus contamination and its prevention effect
Abstract
为预防花生储藏过程中的黄曲霉污染，从农田土中分离出2株拮抗芽孢杆菌，通过平板对峙法优选出1株作为研究对象，研究其对黄曲霉的抑制效果及对花生采后黄曲霉污染的防控效果。采用平板对峙法检测拮抗菌的抑菌广谱性并绘制生长曲线，并通过生理生化实验、形态特征观察及16S rDNA序列分析对该菌株进行鉴定。结果表明：优选出拮抗菌B419作为研究对象，其可有效抑制黄曲霉的生长，在拮抗菌浓度为1.0×106 CFU/mL，黄曲霉孢子浓度为1.0×103 CFU/mL时，黄曲霉孢子萌发抑制率达到98%；相比拮抗菌无菌发酵滤液和拮抗菌细胞悬浮液，拮抗菌发酵液防治花生黄曲霉污染效果最好；该菌株对互隔交链孢霉、枝孢霉、青霉、拟盘多毛孢等多种霉菌都有抑制作用，对大肠杆菌、酵母菌也有抑制作用；该菌株在培养4 h后进入对数期，14 h达到最大，26 h后进入衰亡期；该菌株被鉴定为贝莱斯芽孢杆菌（Bacillus velezensis）。综上，分离的拮抗菌B419对多种微生物都有抑制作用，不仅可以用来预防花生储藏过程中的真菌污染，在防治植物微生物病害方面也具有良好的应用潜力。In order to prevent Aspergillus flavus (A. flavus) contamination of peanut during storage, two antagonist Bacillus sp. were isolated from farmland soil, and one was screened as the subject to study its inhibitory effect on A. flavus and its preventive and control effect on A. flavus contamination of postharvest peanut by plate confrontation method. The inhibitory broad-spectrum of the antagonistic bacterium was detected by plate confrontation method and its growth curve was plotted. The strain was identified through physiological and biochemical test, colony morphological characteristics observation and 16S rDNA gene sequences analysis.The results showed that B419 was screened as the antagonistic bacteria on A. flavus; it could inhibit the growth of A. flavus, and the inhibition rate of A. flavus spore germination could reach 98% when the concentration of antagonistic bacteria was 1.0×106 CFU/mL and the concentration of A. flavus spores was 1.0×103 CFU/mL. Compared with antagonistic bacteria sterile fermentation filtrate and antagonistic bacteria cell suspension, antagonistic bacteria fermentation broth had the best prevention effect on peanut A. flavus. This strain had inhibitory effects on various molds such as Alternaria altemata, Cladosporium sp. , Penicillium sp. and Pestalotiopsis sp. , as well as on Escherichia coli and yeast. The strain entered the logarithmic phase after 4 h of incubation, reached a maximum at 14 h, and entered the decay phase after 26 h of incubation. The strain was identified as Bacillus velezensis. In summary, the isolated antagonistic bacteria B419 has inhibitory effects on various microorganisms, it can not only be used to prevent fungal contamination during peanut storage, but also has good potential in the control of plant microbial diseases.
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