Effect of rapid cooling and acidic pH on cellular homeostasis of Pectinatus frisingensis, a strictly anaerobic beer-spoilage bacterium
Effect of rapid cooling and acidic pH on cellular homeostasis of Pectinatus frisingensis, a strictly anaerobic beer-spoilage bacterium
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DOI：
10.1016/s0168-1605(99)00046-x
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发表时间：
1999-06-01
影响因子：
5.4
通讯作者：
Tholozan, JL
中科院分区：
文献类型：
--
作者：
Chihib, NE;Tholozan, JL
frisingensis是一种严格的厌氧中温细菌，与瓶装啤酒的腐败有关。细胞体积、腺苷酸能量电荷、细胞内pH和细胞内钾浓度测量在不同的生理条件下放置的指数期晚期细胞悬液中进行，以评估该细菌维持细胞内稳态的能力。胞内pH值由胞内[羧基- c -14]苯甲酸积累量计算。最佳生理条件是存在碳源和pH为6.2，不利条件是pH为4.5，缺乏碳源和快速冷却处理。在所有条件下，细胞都能维持较高的细胞内pH值。pH为4.5时细胞内体积小于pH为6.2时。在饥饿细胞中常规测量低净钾外排率，而葡萄糖的添加促进了培养基中立即的净钾摄取。冷却处理导致突然的净钾流出细胞，细胞内pH值降低，代谢葡萄糖细胞悬浮液中腺苷酸能量电荷的低修饰。因此，冷处理扰乱了弗里根假单胞菌的体内平衡，但细菌能够在碳源存在和温暖条件下恢复其体内平衡。(C) 1999 Elsevier Science B.V.版权所有
Pectinatus frisingensis is a strictly anaerobic mesophilic bacterium involved in bottled beer spoilage. Cellular volume, adenylate energy charge, intracellular pH and intracellular potassium concentration measurements were performed in late exponential-phase cell suspensions placed in different physiological conditions, to evaluate the capability of this bacterium to maintain cellular homeostasis. The intracellular pH was calculated from the intracellular accumulation of a [carboxyl-C-14]benzoic acid. Optimum physiological conditions were the presence of a carbon source and pH of 6.2, hostile conditions were a pH 4.5, absence of a carbon source, and rapid cooling treatment. The cell was able to maintain a higher intracellular pH than the external pH under all conditions. Intracellular volume was lower at pH 4.5 than at pH 6.2. A low net potassium efflux rate was routinely measured in starving cells, while glucose addition promoted immediate net potassium uptake from the medium. Cooling treatment resulted in sudden net potassium efflux from the cell, a decrease of the intracellular pH, and low modifications of the adenylate energy charge in metabolizing-glucose cell suspensions. Thus, cold treatment perturbs the P. frisingensis homeostasis but the bacteria were able to restore their homeostasis in the presence of a carbon source, and under warm conditions. (C) 1999 Elsevier Science B.V. All rights reserved.