蜡样芽孢杆菌拮抗菌株的筛选鉴定及其发酵液抗菌活性分析

Screening and identification of antagonistic strain of Bacillus cereus and analysis of antibacterial activity of its fermentation liquid

蜡样芽孢杆菌是一种常见的食源性致病菌,为寻找一种对其有较好抑制作用的抗菌物质,本研究从青海湖淤泥土壤中分离筛选出一株蜡样芽孢杆菌的拮抗菌株,通过形态特征、16S rDNA分子生物学测序和生理生化特征鉴定,确定其分类为短短芽孢杆菌(Brevibacillus brevis).对其抗菌物质研究发现:该抗菌物质具有较好的热稳定性,在80℃水浴中处理20 min后,活性略微有所下降;在紫外线下照射150 min,仍有较强的抑菌活性;在pH6~11的范围内,抑菌活性变化较小.胰蛋白酶对该抗菌物质的稳定性影响较大,而木瓜蛋白酶、蛋白酶k和胃蛋白酶对其影响小.本研究为短短芽孢杆菌抗菌物质的应用提供了理论依据.

Bacillus cereus is a common food-borne pathogen.In order to find an antibacterial substance that can inhibit it,an antagonistic strain of Bacillus cereus was isolated from silt soil of Qinghai Lake.By morphological characteristics,16S rDNA molecular biological sequencing and identification of physiological and biochemical characteristics,it was identified as Brevibacillus brevis.The results showed that the antibacterial substance had good thermal stability.After treatment in 80℃water bath for 20 min,the activity decreased slightly,and antibacterial activity was still strong under ultraviolet radiation for 150 min.In the range of pH 6~11,the change of bacteriostatic activity was small.Trypsin had a greater effect on the stability of the antimicrobial substance,while papain,protease k and pepsin had little effect on it.This study provides a theoretical basis for the application of antimicrobial substances in Bacillus brevis.