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。
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.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2013年第11期218-221,共4页
Food Science
基金
教育部高等学校博士学科点专项科研基金新教师类资助课题(20110172120034)
国家自然科学基金青年科学基金项目(31101279)
中央高校基本科研业务费专项(2011ZM0101)
