发酵食品中产细菌素乳酸菌的筛选与鉴定

Screening and identification of bacitracin-producing lactic acid bacteria from fermented foods

旨在从发酵食品中分离、筛选出产细菌素的乳酸菌。将样品增菌培养,以沙门氏菌、志贺氏菌、单核细胞增生李斯特菌、大肠杆菌和金黄色葡萄球菌等5种致病菌为指示菌,利用双层琼脂扩散法检测发酵上清液的抑菌活性,并通过有机酸、过氧化氢排除试验以及蛋白酶敏感试验确定抑菌物质。试验筛选到1株产细菌素乳酸菌A2,通过形态学观察以及生理生化试验,初步鉴定为植物乳杆菌。

The study was to isolate and screen the bacteriocin-producing lactic acid bacteria from fermented food.Firstly,the samples were enriched and cultured.The antibacterial activity of the fermentation supernatant was detected by double-layer agar diffusion method using five pathogenic bacteria including Salmonella,Shigella,Listeria monocytogenes,Escherichia coli,Staphylococcus aureus as indicator bacteria.Then the antimicrobial substances were determined by organic acid,hydrogen peroxide exclusion test and protease sensitivity test.A lactic acid bacteria strain A2,producing bacteriocin,was screened and preliminarily identified as Lactobacillus plantarum through morphological observation and physiological and biochemical test.