两种乳酸菌及其发酵液对单核细胞增生李斯特菌生长的抑制作用

将单核细胞增生李斯特菌纯培养物分别与保加利亚乳杆菌、嗜热链球菌进行混合培养,观察乳酸菌对单核细胞增生李斯特菌的生物拮抗作用。结果表明,保加利亚乳杆菌和嗜热链球菌对单核细胞增生李斯特菌生长具有明显的抑制作用,并且作用效果随着培养时间的延长而增强;同时,还研究了不同pH值条件下,两种乳酸菌发酵液以及乳酸、盐酸、乙酸对单核细胞增生李斯特菌生长的影响。结果表明,发酵液对单核细胞增生李斯特菌的抑制效果受pH值影响显著。在pH8.0到pH11.0范围内,随着pH值的增加,乳酸菌发酵液的抑菌活性显著下降;乳酸、乙酸对单核细胞增生李斯特菌的抑制作用强于无机酸(盐酸),其中,乙酸的抑制作用最强,且随其含量的增加,抑制作用增强。

Inhibitory Effects of Lactic Bacteria and Their Zymotic Substance on the Growth of Listeria monocytogenes

Listeria monocytogenes was cultivated with Lactobacillus bulgaricus and Streptococcus thermophilus in test tubes to investigate the inhibitory effects of lactobacillus on the growth of L. monocytogenes. The results indicated that L. bulgaricus and S. thermophilus remarkably inhibited the growth of L. monocytogenes, and this inhibitory activity increased along with extending cultivation time. The influence of pH value of zymotic substance from L. bulgaricus and S. thermophilus also significantly affected this inhibitory activity to L. monocytogenes. Meanwhile, the inhibitory effects of lactic acid, hydrochloric acid and acetic acid with different concentrations on L. monocytogenes were studied to understand the role of these acids in the inhibitory effects. The inhibitory effect of lactobacillus metabolic products such as lactic acid and acetic acid on L. monocytogenes was more obvious than that of hydrochloric acid. Acetic acid showed the strongest inhibitory effect and the inhibitory effect increased along with the incresease of acid concentrations.