食品科学

• 生物工程 • 上一篇    下一篇

活的非可培养状态大肠杆菌O157:H7的复苏研究

田 聪,余以刚,肖性龙*,李建龙,吴 晖   

  1. 华南理工大学轻工与食品学院,广东 广州 510640
  • 出版日期:2013-06-15 发布日期:2013-06-03

Resuscitation of Viable but Non-culturable E. coli O157:H7

TIAN Cong,YU Yi-gang,XIAO Xing-long*,LI Jian-long,WU Hui   

  1. College of Light Industry and Food Sciences, South China University of Technology, Guangzhou 510640, China
  • Online:2013-06-15 Published:2013-06-03

摘要:

为研究活的非可培养状态(viable but nonculturable state,VBNC)的Escherichia coli O157:H7的复苏能力,将E.coli O157:H7分别置于LB液体培养基和生理盐水在-18℃低温条件下诱导生产活的非可培养状态E.coli。结合吖啶橙荧光显微镜计数法、活菌直接计数法和平板计数法对样本细菌检测验证,分别在第15天和第18天得到VBNC样本。采用将培养液直接升温到37℃、加入体积分数为25%酵母浸膏(25℃)和加入体积分数为8%吐温-80(37℃)3种方法进行复苏研究。同时利用荧光定量PCR技术监测从诱导到复苏整个过程中的菌数变化。结果显示:3种方法均能使VBNC状态E.coli O157:H7在2d内复苏,复苏后菌株与正常菌株形态类似;细菌进入VBNC状态15d后,采用相同的方法则无法复苏。

关键词: VBNC状态, E.coli O157:H7, 复苏, 检测

Abstract:

In order to explore the resuscitative capability of viable but nonculturable (VBNC) Escherichia coli O157:H7,
the bacteria were induced into LB broth and physiological saline at low temperatures (-18 ℃) respectively. Plate count,
scanning electron microscope and qPCR technique were used to detect the VBNC cell populations on the 15th and 18th days,
respectively. Resuscitation of VBNC samples within 2 d was achieved by direct heating to 37 ℃, addition of 25% yeast
extract at 25 ℃, or addition of 8% Tween-80 at 37 ℃. The pattern of the resuscitated VBNC cells was similar to that of the
normal cells. However, the bacteria could not resuscitate after the VBNC state was kept for 15 d.

Key words: VBNC state, E. coli O157:H7, resuscitation, detection