西藏灵菇中分离两株干酪乳杆菌及其益生特性比较研究

从西藏灵菇中筛选出28株革兰氏染色阳性菌，通过生理生化特征和16S rDNA序列同源性分析分离筛选出2株干酪乳杆菌（Lactobacillus casei）G1、G2，对其进行益生特性比较研究。结果表明，菌株G1、G2均具有较快的产酸能力；均可以在较大温度范围中生长，最适温度为40 ℃左右；具有较强的耐酸性；菌株G2耐胆盐能力明显高于菌株G1；菌株G1、G2对金黄色葡萄球菌（Staphylococcus aureus）、大肠杆菌（Escherichia coli）和沙门氏菌（Salmonella）均具有抑制作用，对大肠杆菌的抑制效果较为明显；菌株G1、G2对抗生素敏感性存在差异，对庆大霉素、诺氟沙星和氯霉素均产生耐药性，呈现多重耐药性。

Comparative analysis of probiotic characteristics of two strains of Lactobacillus casei isolated from Tibetan kefir

Twenty eight strains of gram-positive bacteria were isolated from Tibet kefir. Two strains of Lactobacillus casei G1 and G2 were isolated and identified by physiological and biochemical characteristics and 16S rDNA sequence homology analysis, and their probiotic characteristics were compared and investigated. The results showed that both strains G1 and G2 had faster ability to produce acid and stronger acid resistance. They could grow in a large temperature range. The optimum temperature was about 40 ℃. The cholate resistant ability of strain G2 was apparently higher than that of strain G1. Both strains G1 and G2 had inhibitory effect on Staphylococcus aureus, Escherichia coli and Salmonella, and the inhibitory effect on E. coli was the most obvious. There were different sensitivities of strains G1 and G2 on antibiotics. Strains G1 and G2 had drug resistance on gentamycin, norfloxacin and chloramphenicol, which showed multiple drug resistance.