Antagonistic Action of Lactobacilli Toward Pathogenic Bacteria in Associative Cultures

Lactobacillus spp.에 의한 병원성 세균의 생육저해

Three species of lactobacilli (L. casei, L. acidophilus, L. bulgaricus) were tested for their antibacterial activity. They all were antagonistic to growth of enteropathogenic Escherichia coli and Salmonella enteritidis in associative cultures in YS-medium (0.1 % yeast extract + skimmilk). Sal. enteritidis was more sensitive to the inhibition than was E. coli. Control cultures of E. coli and Sal. enteritidis were pH 5.08 and 5.70 in 72 hrs of incubation and the associative cultures were pH 3.35-4.48. The increases in pH resulting from growth of the lactobacilli in the associative cultures appeared to be sufficient and mainly responsible for the antagonistic actions exerted on the pathogens.

YS-medium(0.1% Yeast extract +10% Skimmilk)중에 유산간균 L.casei, L. acidophilus , L. bulgaricus 와 병원성 E, coli, Sal. enteritides를 혐기적으로 혼합배양하면서 각각의 생육과 저해를 조사한 결과 , E. coli와 Sal. enteritideis의 생육이 각 유산균에 의하여 현저하게 저해되었다. 그러나 L.casei와 L.acidophilus의 각 유산균은 E.coli와 Sal. enteritidis에 의하여 생육이 전혀 저해되지 않았고 , L. bulgaricus는 E. coli 에 의하여 약간 저해를 받았다. E. coli와 Sal. enteritidis 의 단독배양액의 pH는 72시간째에 각각 5.08과 5.70이었으며, 유산균혼합배양액의 pH는 3.75~4.48이었고, 병원성균의 생육억제작용은 주고 pH 저하에 기인하였다.