食品科学 ›› 2006, Vol. 27 ›› Issue (12): 637-641.

• 分析检测 • 上一篇    下一篇

大肠菌群一步发酵法检测的研究

潘慧华,李晶晶,刘坚真   

  1. 广东河源市出入境检验检疫局; 华南农业大学食品学院;
  • 出版日期:2006-12-15 发布日期:2011-11-23

One-step Fermentation of Coliform Bacteria Detection

 PAN  Hui-Hua, LI  Jing-Jing, LIU  Jian-Zhen   

  1. 1.Heyuan Entry-Exit Inspection and Quarantine Bureau, Heyuan 517000, China; 2.College of Food Science, South China Agricultural University, Guangzhou 510642, China
  • Online:2006-12-15 Published:2011-11-23

摘要: 本实验以美国食品与药品管理局(FDA)的初发酵培养基LST以及从国标(GB)乳糖胆盐初发酵培养基中优选出的A3培养基作大肠菌群检测的初发酵基础培养基。首先在LST和A3中分别添加几种不同浓度的革兰氏阳性菌抑制剂进行大肠菌群检测。结果表明,革兰氏阳性菌抑制剂对革兰氏阳性菌和大肠菌群均有抑制,不利于大肠菌群检出。然后,在A3培养基中分别添加大肠杆菌以及枯草杆菌等七种革兰氏阳性菌进行大肠菌群检测。在210支混合发酵管中,结果吻合率为92.42%,假阳性和假阴性分别为2.84%、4.74%。T检验法表明,在初发酵中,革兰氏阳性菌的存在对大肠菌群检测没有明显影响。接着,本实验又在A3培养基中分别添加产生假阳性的革兰氏阳性菌进行纯种发酵检测。在120支假阳性纯种发酵管中,均不会产生阳性反应。大量镜检实验也充分显示,发酵液中主要是革兰氏阴性菌。综上结果说明,A3培养基是一种适宜大肠菌群生长,抑制革兰氏阳性菌生长的初发酵基础培养基,能在短期内使发酵管产气的菌群基本就是大肠菌群。因此,在大肠菌群检测中只需进行一步发酵法检验。

关键词: 大肠菌群, 检测, 一步发酵法

Abstract: Based on the two initial media, LST from FDA and A3 from GB, three types grams positive bacteria inhibitors were added to detect the Coliform bacteria in the food. The result indicated the media with the three grams positive bacteria inhibitors were bad for the detection of Coliform bacteria. Secondly, 7 types of grams positive bacteria were added into the A3 media with E.coli. During the 210 mixed fermentation piles, 92.42% were the same as the comparison fermentation piles, while the false positive ratio and false negative ratio were 2.84%, 4.74%, respectively. The data and the T test analysis showed the influence of grams positive bacteria on Coliform bacteria detection was weak. Thirdly, 4 types of grams positive bacteria caused false positive results were added into the A3 media. It was evident that the grams positive bacteria in the 120 simple fermentation piles didn’t lead to positive results. The results of grams staining illustrated the dominant bacteria in the fermentation liquor of A3 media were grams negative. A3 was a kind of initial fermentation media which was good for Coliform bacteria detection and bad for the growth of grams positive bacteria. Consequently, One-step fermentation was a good method which could detect the Coliform bacteria accurately.

Key words:  , Coliform bacteria; detection; One-step fermentation;