地衣腌菜中产广谱细菌素乳酸菌的筛选与鉴定

采用滤纸片双层平板法从自制酸奶、市售散装腌菜和袋装榨菜中分离出乳酸菌，再对分离的乳酸菌进行抑菌试验、酸和过氧化氢抑制作用的排除、蛋白酶的敏感检测和抑菌谱测定，最后对所得菌株形态和生理生化特性进行鉴定。结果：从样品中筛选到5株具有较高抑菌活性的乳酸菌菌株，在排除了酸和过氧化氢干扰后，发酵上清液仍有很强的抑菌作用；经蛋白酶处理后，发酵液的抑菌活性显著下降，说明该抑菌物具有蛋白质性质，是一类细菌素。这5株菌对绿脓假单胞杆菌、金黄色葡萄球菌、枯草芽孢杆菌和大肠埃希氏菌均有很强的抑菌活性，并选出抑菌活性最强的菌株E2-2，初步鉴定其为戊糖乳杆菌。
A high-efficient and broad-spectrum bacteriocin was developed as a natural food preservative. The lactic acid bacteria were isolated from the home-made yogurt，the marketed unpackaged pickles and the bagged pickles，respectively，using the scrip double-layer plate assay. The isolated lactic acid bacteria was processed by bacteriostasis test，the inhibitory effect test of acid and hydrogen peroxide scavenging，the susceptibility detection of proteinase，and the antibacterial spectrum determination. Finally，the morphologies as well as the physiological and biochemical characteristics of strains were identified. Five lactic acid bacteria strains with higher antimicrobial activity were successfully isolated. Their fermentation supernatants obtained great antimicrobial activity after the exclusion of interference from acid and hydrogen peroxide，while a decrease of the antimicrobial activity was observed after proteinase treatment. The results indicated the isolated strains were proteinaceous bacteriocin. Five strains exhibited high antimicrobial activity against Pseudomonas aeruginosa，Staphylococcus aureus，Bacillus subtilis and Escherichiacoli. The strain E2-2 was selected as the strain of the best antimicrobial activity，which was preliminarily identified as Lactobacillus pentosus