一株猪源发酵乳杆菌的体外特性研究

Characteristics of Lactobacillus fermentumfrom pigs in vitro

采用全自动曲线分析仪测定了猪源发酵乳杆菌X6的不同接种量、不同初始pH的生长曲线;采用琼脂平板扩散法检测该菌的抑菌能力,探讨该菌在不同高温下的存活时间;在体外模拟了该菌对人工胃液和人工肠液的耐受性.结果表明:在接种量1%、初始pH 5.3的条件下,该菌的生长情况最佳;该菌能够抑制大肠杆菌、金黄色葡萄球菌和沙门氏菌的生长;该菌在50、55、60℃处理2min时,存活率分别为99.19%、91.94%、80.65%;该菌在人工肠液和pH 3.0的人工胃液中存在4h后活性几乎不受影响,活菌数在109 CFU/mL以上,说明该菌具备作为益生性饲料添加剂的基本条件.

The growth curve of L.fermentation X6 at different inoculate amount and different initial pH value was determined using automatic curve analyzer.The antibacterial ability of the strain was esti-mated by agar diffusion method and the survival time of the strain was evaluated in different high tempera-tures.Moreover,the tolerance of the strain at simulated gastrointestinal and intestinal fluid was estimated. The results showed that the strain exhibited optimal growth situation when the inoculate amount was 1%and initial pH was 5.3.The growth of Escherichiacoli,Staphylococcusaureus and Salmonella could be in-hibited by L.fermentation X6.The survival rate of the strain X6 was 99.19%,91.94% and 80.65% when incubated at 50 ℃,55 ℃ and 60 ℃ for 2 min.The viable count achieved 109 CFU/mL when the strain X6 sustained in artificial gastric juice （pH 3.0）for 4 hours and in artificial intestinal juice.It is suggested that the strain X6 could be considered as probiotic feed additive.