黑曲霉拮抗细菌的筛选、鉴定和生防条件优化

Screening, Identification and Optimization of Biocontrol Conditions for Antagonistic Bacteria of Aspergillus niger

为筛选出对葡萄贮藏中污染黑曲霉具有良好抑制作用的拮抗菌,本研究通过平板稀释法从土壤中筛选出对葡萄采后引起霉菌病变的黑曲霉有较强抑菌作用的菌株,采用形态学和分子生物学相结合的方式对拮抗细菌进行鉴定,并使用单因素和正交试验方法优化其生防条件。结果表明:本研究从新疆葡萄园土壤中分离到14株对黑曲霉具有抑菌效果的细菌,其中,菌株G8对黑曲霉的抑菌效果最佳。经鉴定,黑曲霉拮抗细菌G8为暹罗芽孢杆菌(Bacillus siamensis)。暹罗芽孢杆菌G8最佳生防条件为:接种量3%,培养基初始pH为7,培养温度为33℃,培养温度摇床转速为160 r/min,培养时间为33 h,该条件下抑菌直径达到28.79 mm。研究结果将为拮抗细菌在葡萄采后黑曲霉生物防治中的应用提供理论依据。

In order to screen for antagonistic bacteria with good inhibitory effect on black fungal disease in grape storage, in this study, strains with strong inhibitory effect on Aspergillus niger, which causes mycorrhizal lesions in grapes after harvest, were screened from soil by plate dilution method, identified using a combination of morphology and molecular biology, and optimized their growth and control conditions using single-factor and orthogonal tests. The results showed that14 strains of bacteria with inhibitory effect on A.niger were isolated from vineyard soil in Xinjiang, among which, strain G8 had the best inhibitory effect on A.niger. The bacterium G8, which can antagonise A. niger, was identified as Bacillus siamensis. The optimum conditions for Bacillus siamensis G8 were: 3% inoculum, initial pH7, incubation temperature of 33 ℃, shaking speed of 160 r/min, and incubation time of 33 h. The inhibition diameter reached 28.79 mm under these conditions. The results of the study will provide theoretical basis for the application of antagonistic bacteria in the biological control of A. niger after grape harvest.