食品科学 ›› 2010, Vol. 31 ›› Issue (5): 252-255.doi: 10.7506/spkx1002-6300-201005057

• 生物工程 • 上一篇    下一篇

贮藏于4 ºC的家制酸奶中低浓度大肠杆菌O157:H7的存活研究

赖卫华1,2,冯贻泽2,*,Beth Ann Crozier-Dodson2   

  1. 1.南昌大学 食品科学与技术国家重点实验室 2.堪萨斯州立大学动物科学与工业系
  • 收稿日期:2008-12-31 出版日期:2010-03-01 发布日期:2010-12-29
  • 通讯作者: 冯贻泽 E-mail:dfung@ksu.edu
  • 基金资助:

    美国Food Safety Consortium 项目(2007-2008);中国留学基金委博士后项目

Survival of Escherichia coli O157:H7 in Home-made Yogurt during Storage at 4 ℃

LAI Wei-hua1,2,Daniel Y. C. Fung2,*,Beth Ann Crozier-Dodson2   

  1. 1. State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China;
    2. Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506, US
  • Received:2008-12-31 Online:2010-03-01 Published:2010-12-29
  • Contact: Daniel Y. C. Fung2,*, E-mail:dfung@ksu.edu

摘要:

牛奶预热后分装并分别接种体积分数3% 的酸奶和2.15(lg(CFU/mL))的大肠杆菌O157:H7,在45℃下发酵5h后贮藏于4℃的冰箱中。利用Pathatrix 大体积循环系统中偶联了抗体的免疫磁珠特异性地捕获这些酸奶中的大肠杆菌O157:H7。免疫磁珠重悬于1% 的蛋白胨水后涂布于添加了新生霉素(5mg/L)的山梨醇麦康凯固体培养基中,培养基在37℃恒温培养箱中放置24h。实验结果表明,酸奶中大肠杆菌O157:H7 的数量逐渐减少,12d 后才检测不到。因此乳制品加工及保存过程中,需要加强对大肠杆菌O157:H7 污染的监测,以保证乳制品的安全性。

关键词: 大肠杆菌O157:H7, 酸奶, Pathatrix 系统

Abstract:

In this study, preheated milk was inoculated with 3% (V/V) of plain yogurt and 2.15 (lg(CFU/mL)) of Escherichia coli O157:H7 to carry out the fermentation at 45 ℃ for 5 h. The resulting fermented yogurt was stored at 4 ℃. Samples were processed using Pathatrix, a large volume recirculating immunomagnetic capture system that utilized paramagnetic beads coated with antibody to facilitate the specific capture of E. coli O157: H7 from yogurt. Then the beads were resuspended in 1% peptone solution, spread onto sorbitol-MacConkey agar and incubated at 37 ℃ for 24 h. E. coli O157:H7 exhibited a gradual decrease and could not be detected after 12 days. Therefore, it is necessary for detecting E. coli O157:H7 during the process of manufacture and storage of dairy products.

Key words: Escherichia coli O157:H7, yogurt, Pathatrix system

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