肠道益生菌体外抑菌活性的研究

An in vitro study of antibacterial activity of 25 strains of probiotics from human gastrointestinal tract

以6种常见肠道致病菌作为指示菌,研究了来自健康青年和儿童肠道的25株益生菌发酵浓缩液的体外抑菌效果。进一步研究了抑菌作用良好的LM a1和LM a3经pH调节、热处理、蛋白酶处理以及发酵过程中的抑菌活性变化。短链有机酸作为发酵终产物的主要成分之一,其抑菌效果也被测定。结果表明,抑菌物质包括短链有机酸(主要为乙酸和乳酸)和一类对热稳定、对部分蛋白酶敏感的物质,可能是某种细菌素。低pH是表现抑菌活性的必要条件,但仅有低pH(如低pH缓冲液)并无明显抑菌效果。

Fermentation concentrated fluids of 25 isolations of Bifidobacteria and Lactobacillus from gastrointestinal tracts of healthy youths and children were studied to detect the antibacteriral activities in vitro, using 6 species of normal intestinal pathogenes indicator organisms. LMal and LMa3 showed higher effects on all 6 species. Acetic acid and lactic acid, main component of fermentation concentrated fluids, which showed antibacterial activity, were confirmed as antibacterial substance, but not the only. Antibacterial substance was pH-dependent and heat-stable. Antibacterial activity of substance was lost after treatment with Trypsin and Papain, which indicates that the substance was a bacteriocin.