• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Applied Microbiology >Intracellular pH Response to Weak Acid Stress in Individual Vegetative Bacillus subtilis Cells
【24h】

Intracellular pH Response to Weak Acid Stress in Individual Vegetative Bacillus subtilis Cells

机译：细胞内pH对单个植物枯草芽孢杆菌细胞中弱酸胁迫的反应

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Intracellular pH (pH_(i)) critically affects bacterial cell physiology. Hence, a variety of food preservation strategies are aimed at perturbing pH_(i) homeostasis. Unfortunately, accurate pH_(i) quantification with existing methods is suboptimal, since measurements are averages across populations of cells, not taking into account interindividual heterogeneity. Yet, physiological heterogeneity in isogenic populations is well known to be responsible for differences in growth and division kinetics of cells in response to external stressors. To assess in this context the behavior of intracellular acidity, we have developed a robust method to quantify pH_(i) at single-cell levels in Bacillus subtilis . Bacilli spoil food, cause disease, and are well known for their ability to form highly stress-resistant spores. Using an improved version of the genetically encoded ratiometric pHluorin (IpHluorin), we have quantified pH_(i) in individual B. subtilis cells, cultured at an external pH of 6.4, in the absence or presence of weak acid stresses. In the presence of 3 mM potassium sorbate, a decrease in pH_(i) and an increase in the generation time of growing cells were observed. Similar effects were observed when cells were stressed with 25 mM potassium acetate. Time-resolved analysis of individual bacteria in growing colonies shows that after a transient pH decrease, long-term pH evolution is highly cell dependent. The heterogeneity at the single-cell level shows the existence of subpopulations that might be more resistant and contribute to population survival. Our approach contributes to an understanding of pH_(i) regulation in individual bacteria and may help scrutinizing effects of existing and novel food preservation strategies.IMPORTANCE This study shows how the physiological response to commonly used weak organic acid food preservatives, such as sorbic and acetic acids, can be measured at the single-cell level. These data are key to coupling often-observed single-cell heterogeneous growth behavior upon the addition of weak organic acid food preservatives. Generally, these data are gathered in the form of plate counting of samples incubated with the acids. Here, we visualize the underlying heterogeneity in cellular pH homeostasis, opening up avenues for mechanistic analyses of the heterogeneity in the weak acid stress response. Thus, microbial risk assessment can become more robust, widening the scope of use of these well-known weak organic acid food preservatives.
机译：细胞内pH（pH_（i））至关重要地影响细菌细胞生理学。因此，各种食物保存策略旨在扰动pH_（i）稳态。遗憾的是，具有现有方法的准确pH_（i）量化是次优的，因为测量是细胞群体的平均值，而不是考虑到的间面的异质性。然而，众所周知，中源性群体中的生理异质性是对细胞生长和分裂动力学的差异响应外部压力源的差异。为了评估这种情况，细胞内酸度的行为，我们已经开发了一种稳健的方法，以在枯草芽孢杆菌中的单细胞水平下量化pH_（i）。 Bacilli破坏食物，引起疾病，并且众所周知，它们能够形成高抗应力的孢子。使用改进的遗传编码的比率嘌呤素（Iphluorin）（Iphluorin），我们在单个B.枯草芽孢杆菌细胞中定量pH_（i），在弱酸胁迫下在6.4的外部pH下培养。在3mM山梨酸钾存在下，观察到pH_（i）的降低和生长细胞的产生时间的增加。当用25mM乙酸钾胁迫将细胞胁迫时，观察到类似的效果。生长菌落中个体细菌的时间分辨分析表明，在瞬态pH降低后，长期pH进化是高度细胞依赖性。单细胞水平的异质性显示出存在可能更耐药和有助于种群存活的群体的存在。我们的方法有助于了解个体细菌的pH_（i）调节，并有助于审查现有和新的食物保存策略的影响。分析本研究表明，该研究表明如何对常用的弱有机酸食品防腐剂的生理反应如何，例如山梨酸和醋酸酸可以在单细胞水平下测量。这些数据是在添加弱有机酸食品防腐剂时偶联通常观察到的单细胞异质生长行为的关键。通常，这些数据以与酸温育的样品的板计数的形式聚集。在这里，我们可视化细胞pH稳态中的潜在异质性，打开弱酸应激反应中的异质性的机械分析的途径。因此，微生物风险评估可能变得更加坚固，扩大了这些众所周知的弱有机酸食品防腐剂的使用范围。

著录项

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