以实验室保存的一株费氏丙酸杆菌CS1420（Propionibacterium freudenreichii CS1420）为试验菌株。首先考察了不同初始pH下对其发酵产细菌素的影响。结果表明：以大肠杆菌ATCC25922为指示菌，当培养基初始pH为6.0时，细菌素抑菌效果最好；以Saccharomyces cerevisiae 2-10515为指示菌，当培养基初始pH为5.5时，细菌素抑菌效果最好。然后用丙酸调节细菌素粗提物的pH进行抑菌试验，结果表明，pH对粗提得到的细菌素抑菌性影响很大，当用丙酸将细菌素溶液的pH调至5.5时，细菌素的抑菌活性有显著提高。%Propionibacterium freudenreichii CS1420 was as experimental strains. Firstly,the effects of different pH on fermentation of Propionibacterium freudenreichii Bacteriocins were investigated. The result showed:the antimicrobial activity were best by using Eoli ATCC25922 as indicator strains when the medium initial pH was 6.0,the antimicrobial activity were best by using Saccharomyces cerevisiae 2-10515 as indicator strains when the medium initial pH was 5.5. Then,bacteriocins crude extract pH were adjusted and then bacteriostatic exper-iments were carried out. The result showed:the effect of pH on crude extract bacteriocins was tremendous. The antimicrobial activity of bacteriocins improved significantly when crude extract bacteriocins solution pH were adjusted 5.5 with propionic acid.
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