产细菌素乳酸菌的筛选与鉴定

Screening and Identification of Bacteriocin-producing Lactic Acid Bacteria

从蒙古国风干牛肉中分离出28株乳酸菌,以大肠杆菌、金黄色葡萄球菌和单核增生李斯特菌为指示菌检测28株乳酸菌的抑菌活性,其中菌株37X-3和菌株37X-13对3种指示菌的抑菌能力较强,且经胃蛋白酶和蛋白酶K处理后抑菌活性全部丧失,表明2株乳酸菌通过产细菌素的方式发挥抑菌作用。再经表型、生理生化和基因型鉴定,确定菌株37X-3为戊糖片球菌,菌株37X-13为乳酸片球菌。2种片球菌素在121℃,15 min,pH 2~6范围均能抑制3种指示菌的生长,且对单核增生李斯特菌抑菌作用最强。2种片球菌素抑菌谱广,不仅能抑制枯草芽孢杆菌、屎肠球菌等革兰氏阳性菌,还能抑制沙门氏菌、志贺氏菌等革兰氏阴性菌。

The 28 strains of lactic acid bacteria was isolated from Mongolian dried beef.The antibacterial activity of 28 strains of lactic acid bacteria were detected by Escherichia coli,Staphylococcus aureus and Listeria monocytogenes as indicator bacteria.The strain 37X-3 and strain 37X-13 have strong bacteriostatic ability of the three kinds of indicator bacteria,and all the bacteriostatic activities are lost after pepsin and proteinase K treatment,indicating that the two lactic acid bacteria exert bacteriostasis by producing bacteriocins effect.The 37X-3 produced Pediococcus pentosaceus,37X-13 produced Pediocin acidilactici by the identification of phenotype,physiological,biochemical and genetic type.The 2 pediocin could inhibit the growth of the three kinds of indicator bacteria at 121℃,15 min and pH 2-6,and had the strongest antibacterical effect on Listeria monocytogenes.The 2 pediocin had a wide spectrum of inhibition,which could inhibit not only Gram-positive bacteria such as Bacillus subtilis and Enterococcus faecalis,but also Gram-negative bacteria such as Salmonella enterica and Shigella castellani.