1株产细菌素乳酸菌的筛选和鉴定

目的 从植物性材料中筛选产细菌素的乳酸菌。方法 琼脂扩散法。结果 所筛选的产细菌素R260菌株经鉴定为植物乳杆菌。排除有机酸、过氧化氢等干扰因素后，发酵液仍有很强的抑菌作用；用胰蛋白酶和胃蛋白酶处理后，发酵液抑菌活性急剧下降，因而确定产生的抑菌物质具有蛋白质性质，是一种细菌素。抑菌谱试验测定表明，此菌株的发酵液不仅抑制革兰阳性菌，而且对部分革兰阴性菌也有抑制作用，因此产生的是一类广谱细菌素。结论筛选到了1株产广谱细菌素的乳酸菌。

Identification and screening of bacteriocin-producing Lactic acid bacteria strains

Objective Bacteriocin-producing Lactic acid bacteria was isolated from plant-material. Method Agar diffusion test. Results Bacteriocin-produeing R260 strain was identified as Lactobacillus plantarum by physiological and biochemical experiments. The supernatant of R260 strain could inhibit the growth of indicator strains fiercely excluded hydrogen peroxide and organic acid, but the inhibitive activity decreased sharply after treatment with trypsin and pepsin, which showed that this inhibitory material had the features of protein, could be classed as bacteriocin. The test of bacterial inhibition spectrum proved that the supernatant of Lactobacillus plantarum R260 could inhibit not only gram-positive bacteria but also gram-negative bacteria. Therefore, this strain produced a bacteriocin of wide inhibition spectrum. Conclusion A wide inhibition spectrum bacteriocin-producing Lactic acid bacteria strain was isolated.