一株安徽传统酸奶中产抑菌物质的乳酸菌的筛选与鉴定

Isolation and identification of a bacteriostatic-producing lactic acid bacterium from traditional fermented milk in Anhui

中文关键词:  传统酸奶  乳酸菌  抑菌物质  筛选鉴定

英文关键词:traditional fermented milk  lactic acid bacterium  bacteriostatic  isolation and identification

中文摘要:

      目的 从安徽传统发酵酸奶中筛选出一株具有抑菌活性的乳酸菌(编号为SN-5)。方法 通过菌落形态观察、染色镜检、生理生化和分子生物学实验进行鉴定分析, 利用牛津杯法进行抑菌实验。结果 通过实验排除乳酸、乙酸和过氧化氢干扰后, L. delbrueckii ssp. bulgaricusSN-5的无细胞发酵上清液(cell-free fermentation supernatant, CFS)对大肠杆菌(ATCC 8099)和金黄色葡萄球菌(ATCC 6538)仍具有抑制作用, 且经胰蛋白酶、胃蛋白酶和胃蛋白酶K处理后抑菌作用下降明显, 说明L. delbrueckii ssp. bulgaricusSN-5所产主要抑菌物质为蛋白类物质。结论 L. delbrueckii ssp. bulgaricusSN-5可作为食品运输和贮藏过程中控制大肠杆菌和金黄色葡萄球菌的拮抗制剂出发菌株, 为新型生物防腐剂的开发奠定了一定的理论基础。

英文摘要:

      Objective To screeneda antibacterial activity strain (number SN-5) of lactic acid bacterium from traditional fermented milk in Anhui. Methods Identification and analysis were carried out by colony morphology observation, staining microscopy, physiological biochemistry and molecular biology experiments, and the bacteriostasis experiment was carried out by using the Oxford Cup method. Results The antimicrobial activity of the cell-free culture supernatant (CFS) of L. delbrueckiissp. bulgaricus SN-5 against Escherichia coli (ATCC 8099) and Staphylococcus aureus (ATCC 6538) still existed after eliminating the interference factors such as lactic acid, acetic acid and hydrogen peroxides. However, after treatment with proteolytic enzymes, the antimicrobial activity of the CFS of L. delbrueckiissp. bulgaricus SN-5 decreased obviously, which indicated that that the main bacteriostatic substance of L. delbrueckiissp. bulgaricus SN-5 was protein substance. Conclusion L. delbrueckii ssp. bulgaricus SN-5 can be used as a starting strain for the control of Escherichia coli and Staphylococcus aureus in food transportation and storage, which canlay a theoretical foundation for the development of new biological preservatives.