一株黄曲霉拮抗细菌F1的筛选、鉴定及其抑菌特性

为获得能有效抑制食品原料中黄曲霉生长的生防细菌，本研究以乳酸菌发酵制品和香辛料为筛菌出发样品，通过菌株分离、初筛和复筛，从黑胡椒中筛选到一株对黄曲霉有强烈抑制作用的菌株F1。依据菌株的形态特征、培养特征、生理生化特征结合16S rDNA基因序列分析、系统发育树构建来鉴定菌株，最终确定菌株F1为解淀粉芽孢杆菌Bacillus amyloliquefaciens（保藏编号：CGMCC No. 10942），与已商品化的生防菌Bacillus amyloliquefaciens FZB42的亲缘关系最为接近。菌株F1的发酵上清液经过超滤处理以及蛋白酶酶解试验和稳定性试验，结果显示，菌株F1的抑菌成分为分子量30 ku~100 ku的蛋白类物质；在100 ℃处理30 min后仍能保持87.43%的抑菌活性；在pH值3.0~10.0范围内其相对抗菌活性均在70%以上。研究表明，从黑胡椒中分离到的解淀粉芽孢杆菌F1能够通过代谢产生稳定性较强的抗菌蛋白而达到拮抗黄曲霉的目的，在食品领域具有一定的应用前景。
To obtain a biocontrol bacteria that can effectively suppress the growth of Aspergillus flavus in raw food materials, products fermented by lactic acid bacteria and spices were used as the starting materials. One strain, F1, was screened from black pepper through strain isolation, preliminary screening, and re-screening, and showed a strong inhibitory effect towards Aspergillus flavus. This strain was identified based on morphological, cultural, physiological, and biochemical characteristics, and the 16s rDNA analysis followed by phylogenetic tree construction, to be Bacillus amyloliquefaciens (Preservation number: CGMCC No. 1094). The strain had a close genetic relationship with the commercialized biocontrol strain Bacillus amyloliquefaciens FZB42. The culture supernatant of strain F1 was subjected to ultrafiltration treatment, enzymatic hydrolysis test, and stability test. The results implied that the antifungal component of strain F1 was protein substances with molecular weights of 30 ku~100 ku. About 87.43% of the antifungal activity remained after the treatment at 100 ℃ for 30 min, and over 70% of antifungal activity remained when the pH was in the range of 3.0~10.0. This study suggests that the strain Bacillus amyloliquefaciens F1, isolated from black pepper, can produce relatively stable antifungal proteins through metabolism, and, thus, present an antagonistic effect on Aspergillus flavus. Therefore, this strain has the potential for application in food products.