西藏灵菇中抑真菌乳酸菌的筛选和鉴定

Isolation and identification of antifungal lactic acid bacteria from Tibetan mushroom

从西藏灵菇发酵乳中筛选到2株对霉菌有抑菌作用的乳酸菌。通过RiboPrinter全自动微生物基因指纹鉴定系统和16SrDNA序列同源性分析,鉴定该2菌株均为副干酪乳杆菌。排除低pH、过氧化氢等因素的影响,无细胞上清液仍对指示菌有强的抑菌作用。它对胰蛋白酶、蛋白酶K、胃蛋白酶和α-糜蛋白酶不敏感。耐热性强(121℃,20min)及低pH值(<6.0)有强抑菌活性。抑菌谱广,不仅对多种霉菌有抑菌活性,对金黄色葡萄球菌和大肠杆菌也有强的抑菌活性。

Two strains of lactic acid bacteria, isolated from Tibetan mushroom, have strong antifungal activity against molds. These strain was identified as Lactobacillus paracasei by its Riboprinter Microbial Characterization System and 16S rDNA gene sequencing. The supernatant of these strain could inhibit the growth of indicator strain strongly after excluding hydrogen peroxide and low pH. It was not sensitive to trypsin, proteinase K, pepsin and a-chymotrypsin. These bacteriocins were resistant to heating at 121 ℃ for 20 minutes and showed highest activity at low pH （〈6.0）. The bacteriocins had a wide spectrum of activity as antagonism was detected not only towards a variety of molds, but also to Staphylococcus aureus and Escherichia coli.