牦牛奶酪中产细菌素乳酸菌菌株的筛选

Screening for Bacteriocin-Producing Strains of Lactic Acid Bacteria in Yak Cheeses

本研究用分离自西藏、新疆、云南地区牦牛奶酪的39株乳酸菌作为供试菌株,制备细菌素粗提液,用琼脂井法分析粗提液对9株致病菌(蜡样芽孢杆菌、金黄色葡萄球菌、埃希氏大肠杆菌O157:H7、单增李斯特菌、费氏柠檬酸杆菌、鼠伤寒沙门氏菌、阴沟肠杆菌、产气荚膜梭菌、宋内志贺菌)和2株非致病菌(无害李斯特菌、嗜热链球菌)指示菌株的抑菌作用。测定结果表明有30株菌的细菌素粗提液对指示菌株有抑菌作用,筛选出Y13、X29和X30这3株抑菌谱较宽的细菌素产生菌。

This study analyzed the bacteriocin-producing capability of 39 lactic acid bacteria strains isolated from yak cheeses collected from Tibet, Xinjiang and Yunnan province of China. The crude extracts rich in bacteriocin were prepared.Agar well-diffusion method was used to test their bacteriostatic activities against 9 pathogenic reference strains(Bacillus cereusStaphylococcus aureusEscherichia coli O157:H7, Listeria monocytogenesCitrobacterfreundiiSalmonella typhimuriumEnterobacter cloacaeClostridium perfringensand Bacterium sonneias well as 2 non-pathogenic reference strains(Listeria monocytogenes and Streptococcus thermophilusThe crude extracts of 30 out of the 39 stains exhibited bacteriostatic activities against these reference strains. Three strains, namely Y13, X29 and X30, were selected as excellent bacteriocin-producing strains with a broad antimicrobial spectrum. They hold promise for potential applications in the prevention and control of food-borne pathogenic bacteria.