1株拮抗细菌的分离鉴定及其对香蕉枯萎病等病原菌的抑制活性测定

Screening, Identification of an Antagonistic Bacteria and Determinning a Method to Inhibit 12 Pathogenic Fungus,Such as Fusarium oxysporum f. sp. cubense

为了增加生防制剂的有效成分来源,从食物黄豆酱中分离筛选得到4株拮抗细菌,以香蕉枯萎病为指示菌,采用平板对峙法测定菌株抑菌谱,获得1株具有稳定抑制活性的拮抗细菌。通过鉴定菌株的形态特征、生理生化特性及16S r DNA基因序列比对分析,初步确定该拮抗菌株Y-4是解淀粉芽胞杆菌(Bacillus amyloliquefaciens),并测定在不同状态和处理操作下菌株的抑制活性。结果表明:菌株Y-4对香蕉枯萎病等12种病原真菌均有较强抑制活性,抑菌率为53.33%~86.67%。其中对香蕉枯萎病菌4号小种病原菌的抑菌率为63.33%,其发酵液也具有一定抑菌活性,对粗蛋白进行不同浓度活性测定,在2 000μg/m L时对香蕉枯萎病菌4号小种的抑制效果最佳。乙醇萃取物对峙12种病原真菌的抑菌率最高达70%。从食物中分离出的菌株Y-4具有稳定的抑菌活性,为香蕉枯萎病生防制剂的研制拓展新的研究领域。

In order to increase the effective component of the Biocontrol Medicament, four antagonistic bacteria were isolated from the food of soybean paste in this article. The method of tablet confrontation was used to determine the bacterial strain of the bacterium, and to obtain a resistant bacteria with stable inhibitory activity.Preliminary identification of strain Y-4 was Bacillus amyloliquefaciens through the observation of morphology, and the analysis of physiological and biochemical characteristics, and 16 S r DNA sequence. Measuring the different state and operation in the inhibition activity of the strain. The results showed： The strain of Y-4 had strong inhibiting activity in 12 Pathogenic fungus, such as Fusarium oxysporum f. sp. cubense, The bacteriostatic rate was 53.33%~86.67%. Among them, the bacteriostatic rate of Fusarium oxysporum f. sp. cubense was 63.33%, the Fermentation liquid has certain bacteriostas was activity. Performed the Inhibition effect to different concentrations of crude protein, and the inhibition effect to Fusarium oxysporum f. sp. cubense was the best in 2 000 mg/m L. The antibacterial rate of the twelve pathogenic fungi was up to 70% with Ethanol extract. The strain of Y-4 was isolated from the food had stable bacteriostatic activity, to develop new research fields for the Biocontrol Medicament of Fusarium oxysporum f. sp. cubense.