食品科学

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热胁迫下沙门氏菌亚致死规律及机制

汪月霞1,侯鹏飞1,索 标2,*   

  1. 1.河南农业大学生命科学学院,河南 郑州 450002;2.河南农业大学食品科学技术学院,河南 郑州 450002
  • 出版日期:2013-07-15 发布日期:2013-06-28
  • 通讯作者: 索 标
  • 基金资助:

    国家自然科学基金项目(U1204331);河南省科技攻关重点项目(122102310310);河南省教育厅科学技术研究重点项目(13A550486)

Effect and Mechanism of Sublethal Heat Stress on Salmonella Typhimurium

WANG Yue-xia1,HOU Peng-fei1,SUO Biao2,*   

  1. 1. College of Life Sciences, Henan Agricultural University, Zhengzhou 450002, China;
    2. College of Food Science and Technology, Henan Agricultural University, Zhengzhou 450002, China
  • Online:2013-07-15 Published:2013-06-28
  • Contact: SUO Biao

摘要:

为研究热胁迫下沙门氏菌亚致死规律及调节机制,首先研究沙门氏菌在不同温度下的亚致死及生长曲线, 进而采用Realtime PCR技术研究亚致死沙门氏菌细胞膜完整性和σ因子转录表达水平的变化。结果表明:沙门氏菌 经过60℃热激处理后,细胞外膜和质膜均发生明显的亚致死损伤,细胞膜完整性被破坏。而经过42℃较低温度热胁 迫处理后,沙门氏菌的生长曲线与对照相比无明显差异,细胞外膜和质膜也没有受到明显的亚致死损伤,细胞膜完 整性也未受到明显的破化,并推测可能与σ因子的转录诱导有关。本实验初步揭示了亚致死状态是沙门氏菌在热处 理下失活过程中的中间过渡状态,并且与细胞膜的完整性和关键基因的转录表达调节密切相关,为食品热加工安全 技术的建立提供新的思路。

关键词: 沙门氏菌, 亚致死, 热胁迫, 细胞膜完整性, &sigma, 因子转录调节

Abstract:

In order to study the sublethal characteristic and regulation mechanism of Salmonella Typhimurium in response
to heat stress, its sublethal and growth curves under different high temperature were investigated. The cell membrane integrity
and changes of transcriptional sigma factors in sublethal Salmonella Typhimurium were analyzed using real-time PCR. Results
showed that significant injuries occurred on the outer and cytoplasmic membranes of Salmonella Typhimurium following heat
treatment at 60 ℃ and a significant damage in cell membrane integrity was also observed. The growth curve and damage in
cell membrane integrity following heat treatment at 42 ℃ was not significantly different from those of the control. This finding
might be associated with the transcriptional induction of sigma factors. The current preliminary study revealed that the sublethal
state of Salmonella Typhimurium exposed to heat stress might be the intermediate transition state in the process of inactivation,
which could be closely linked to the cell membrane integrity and key gene expression and regulation. The findings in this study
presented useful insights for the establishment of thermal processing techniques for microbiologically safe foods.

Key words: Salmonella Typhimurium;sublethal injury;heat stress;cell membrance integrity;transcriptional regulation of &sigma, factors

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