以益生菌凝结芽孢杆菌Bacillus coagulans LL1103为对象，研究了其生长情况与pH值和抑菌活性的关系，发现其最佳抑菌发酵时间为18 h。制备了其抑菌产物粗品并测定其抑菌谱，结果表明，抑菌产物对革兰氏阴性菌和革兰氏阳性菌均有明显的抑菌效果，具有广谱抗菌性。随后对抑菌产物粗品的理化性质进行了研究，发现它在MRS培养基中培养后，最适温度37℃，最适pH=6.0下具有最强的抑菌活性。此外，进行了抑菌物质的初步鉴定，在排除酸性末端产物和菌体的干扰后，用蛋白酶K等多种蛋白酶和过氧化氢酶去处理抑菌产物粗品，发现其对蛋白酶K、胰蛋白酶、胃蛋白酶较敏感，对氧化氢酶不敏感，初步推断抑菌物质的主要成分是对蛋白酶敏感的细菌素类物质。%In the present study, the relationship among growth condition, pH and bacteriostatic activity of probiotics Bacillus coagulans LL1103 was examined, and the optimal fermentation time for antibacterial substance producing was 18 h. The antibacterial crude extract was then prepared for antibacterial spectrum measuring. The results showed that the extract had a broad spectrum of significant bacteriostatic activity , including activities against gram-negative bacteria and gram-positive bacteria. In addition , the maximal bacteriostatic activity of this extract was observed by incubating B. coagulans LL1103 in MRS medium at 37°C, pH 6.0. Furthermore, we found that antibacterial product was sensitive to protease K, trypsin and pepsin, but not hydrogen oxidation enzymes. Thus, we speculated that the main ingredients of antibacterial product was a kind of bacteriocin which was sensitive to proteases.
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