• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Food microbiology >Escherichia coli population heterogeneity: Subpopulation dynamics at super-optimal temperatures
【24h】

Escherichia coli population heterogeneity: Subpopulation dynamics at super-optimal temperatures

机译：大肠杆菌种群异质性：超最佳温度下的亚种群动态

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

In the past years, we explored the dynamics of Escherichia coli K12 at super-optimal temperatures under static and dynamic temperature conditions (Van Derlinden et al. (2008b, 2009, 2010). Disturbed sigmoid growth curves, i.e., a sequence of growth, inactivation and re-growth, were observed, especially close to the maximum growth temperature. Based on the limited set of experiments (i.e., 2 static temperatures and 2 dynamic temperature profiles), the irregular growth curves were explained by postulating the co existence of two subpopulations: a more resistant, growing population and a temperature sensitive, inactivating population. In this study, the dynamics of the two subpopulations are studied rigorously at 11 constant temper ature levels in the region between 45℃ and 46℃, with at least five repetitions per temperature. At all temperatures, the total population follows a sequence of growth, inactivation and re-growth. The sequence of different stages in the growth curves can be explained by the two subpopulations. The first growth phase and the inactivation phase reflect the presence of the sensitive subpopulation. Hereafter, the population's dynamics are dominated by the growth of the resistant subpopulation. Generally, cell counts are characterized by a large variability. The dynamics of the two subpopulations are carefully analyzed using a heterogeneous subpopulation type model to study the relation between the kinetic parameters of the two subpopulations and temperature, and to evaluate if the fraction d of resistant cells varies with temperature. Results indicate that the growth rate of the sensitive subpopulation decreases with increasing temperature within the range of 45—46℃. Furthermore, results point in the direction that the duration of this initial growth phase is approximately constant, i.e., around 2 h. Possibly, the stress resistance of the cells decreases after a certain period because the metabolism is fully adapted to exponential growth. Also, the growth rate of the resistant subpopulation decreases with increasing temperature. Due to the extreme variability in the cell density data, derivation of accurate relations was not possible. From the heterogeneous model implementations, given the experimental set-up, both a constant d value and a temperature dependent d value seem plausible.
机译：在过去的几年中，我们探索了大肠杆菌K12在静态和动态温度条件下在最佳温度下的动态变化（Van Derlinden等人（2008b，2009，2010）。乙状结肠生长曲线受干扰，即一系列增长，观察到失活和重新生长，特别是接近最高生长温度，基于有限的一组实验（即2个静态温度和2个动态温度曲线），通过假设两个共同存在来解释不规则的生长曲线亚种群：具有更强的抗性，正在增长的种群和对温度敏感的灭活种群：在这项研究中，在45℃至46摄氏度之间的11个恒定温度水平下，严格研究了这两个亚种群的动态，至少重复了5次。在所有温度下，总种群都遵循生长，失活和再生长的顺序，可以显示生长曲线中不同阶段的顺序受这两个子群体的影响。第一生长阶段和失活阶段反映了敏感亚群的存在。此后，抗药性亚种群的增长决定了种群的动态。通常，细胞计数的特点是变异性大。使用异质亚种群类型模型仔细分析两个亚种群的动力学，以研究两个亚种群的动力学参数与温度之间的关系，并评估耐药细胞的分数d是否随温度变化。结果表明，在45-46℃范围内，随着温度的升高，敏感亚群的生长速率降低。此外，结果指向该初始生长期的持续时间近似恒定的方向，即约2小时。可能的是，由于新陈代谢完全适应指数增长，因此细胞的抗逆性在一定时期后会降低。而且，抗性亚群的生长速率随温度升高而降低。由于细胞密度数据的极端可变性，不可能得出精确的关系。从异质模型实现中，给定实验设置，恒定的d值和与温度有关的d值似乎都是合理的。

著录项

  • 来源
    《Food microbiology》 |2011年第4期|p.667-677|共11页
  • 作者

    E. Van Derlinden; Boons; J.F. Van Impe;

  • 作者单位

    CPMF2, Flemish Cluster Predictive Microbiology in Foods, Belgium,BioTeC, Chemical and Biochemical Process Technology and Control, Katholieke Universiteit Leuven, W. de Croylaan 46, B-3001 Heverlee, Belgium;

    CPMF2, Flemish Cluster Predictive Microbiology in Foods, Belgium,BioTeC, Chemical and Biochemical Process Technology and Control, Katholieke Universiteit Leuven, W. de Croylaan 46, B-3001 Heverlee, Belgium;

    CPMF2, Flemish Cluster Predictive Microbiology in Foods, Belgium,BioTeC, Chemical and Biochemical Process Technology and Control, Katholieke Universiteit Leuven, W. de Croylaan 46, B-3001 Heverlee, Belgium;

  • 收录信息 美国《科学引文索引》(SCI);美国《化学文摘》(CA);
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

    Escherichia coli; Temperature; heterogeneous population; Subpopulation; Stress;

    机译：大肠杆菌;温度;异质种群;亚种群;胁迫;

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号