新疆传统干酪中1株产广谱细菌素乳酸菌的筛选及其生物学特性

利用牛津杯法从新疆传统干酪中筛选出1株对大肠杆菌（Escherichia coli）、枯草芽孢杆菌（Bacillus subtilis）、李斯特氏菌（Listeria monocytogenes）金黄色葡萄球菌（Staphylococcus aureus）均具有明显抑制作用的乳酸菌。经排除酸、过氧化氢干扰后，此菌株的发酵上清液仍然具有较强的抑菌性。经胃蛋白酶和胰蛋白酶处理后，抑菌活性明显降低，表明其发挥抑菌作用的物质是细菌素。通过对该菌株的生长特性研究和生理生化分析以及16S rRNA基因序列分析，该菌株被鉴定为肠球菌属（Enterococcus sp.）。在酸性条件下，对胃蛋白酶和胰蛋白酶敏感，发酵上清液经高温、尿素、十二烷基硫酸钠（SDS）、乙二胺四乙酸（EDTA）、聚乙二醇辛基苯基醚（Triton X-100）、吐温-80（Tween-80）处理下抑菌活性仍然保持稳定，为乳酸菌开发作为生物型防腐剂奠定基础。

Screening of a broad-spectrum bacteriocin-producing lactic acid bacteria strain from XinJiang traditional cheese and its biological characteristics

A lactic acid bacteria strain which has obvious inhibitory effect on Escherichia coli, Bacillus subtilis, Listeria monocytogenes, Staphylococcus aureus was screened by Oxford cup method. However, after pepsase and trypsin treatment, the antimicrobial activity decreased obviously, it showed that the antimicrobial substance was bacteriocin. On the basis of growth characteristic and biochemical characterizations, basis on 16S rDNA secquence analyse, the strain was identified as Enterococcus sp. Under acid condition, it was sensitive to pepsin and trypsin. The fermentation supernatant was treated by high temperature, urea, SDS, EDTA, TritionX-100 and Tween 80, the inhibitory activity remained stable. The result laid a foundation for the development of lactic acid bacteria as biological preservatives.