Variation in Bacterial ATP Level and Proton Motive Force Due to Adhesion to a Solid Surface
Variation in Bacterial ATP Level and Proton Motive Force Due to Adhesion to a Solid Surface
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DOI：
10.1128/aem.02671-08
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发表时间：
2009-04-01
影响因子：
4.4
通讯作者：
Brown, Derick G.
中科院分区：
文献类型：
--
作者：
Hong, Yongsuk;Brown, Derick G.
细菌粘附到自然和人造表面可能是有益的或有害的，这取决于手头的系统。至关重要的是粘附过程如何影响细菌的代谢活性。如果活性增强，这可能有助于细胞在表面上定植，而如果活性降低，则可能抑制定植。在这里，我们报告了一项研究表明，大肠杆菌和短芽孢杆菌粘附到玻璃表面上导致代谢活性增强，通过ATP测量评估。具体地，发现与相应的促炎细胞中的ATP水平相比，粘附后ATP水平增加2至5倍。为了解释这种对ATP水平的影响，我们提出了一个假设，即细菌可以利用细胞生物能学（质子动力和ATP形成）和物理化学电荷调节效应之间的联系，这种作用是作为含有可电离官能团的表面发生的（例如，例如，在一个实施例中，细菌细胞表面）接近另一个表面。当细菌接近表面时，电荷调节效应导致细胞表面的电荷和pH值随分离距离而变化。对于带负电荷的表面，这导致细胞表面的pH值降低，这增强了质子动力和ATP浓度。计算表明，仅0.2至0.5单位的细胞膜pH值变化就足以实现观察到的ATP增加。类似地，该假设表明带正电荷的表面会降低代谢活性，并且来自带正电荷的表面的研究结果支持这一发现。
Bacterial adhesion to natural and man-made surfaces can be beneficial or detrimental, depending on the system at hand. Of vital importance is how the process of adhesion affects the bacterial metabolic activity. If activity is enhanced, this may help the cells colonize the surface, whereas if activity is reduced, it may inhibit colonization. Here, we report a study demonstrating that adhesion of both Escherichia coli and Bacillus brevis onto a glass surface resulted in enhanced metabolic activity, assessed through ATP measurements. Specifically, ATP levels were found to increase two to five times upon adhesion compared to ATP levels in corresponding planktonic cells. To explain this effect on ATP levels, we propose the hypothesis that bacteria can take advantage of a link between cellular bioenergetics (proton motive force and ATP formation) and the physiochemical charge regulation effect, which occurs as a surface containing ionizable functional groups (e. g., the bacterial cell surface) approaches another surface. As the bacterium approaches the surface, the charge regulation effect causes the charge and pH at the cell surface to vary as a function of separation distance. With negatively charged surfaces, this results in a decrease in pH at the cell surface, which enhances the proton motive force and ATP concentration. Calculations demonstrated that a change in pH across the cell membrane of only 0.2 to 0.5 units is sufficient to achieve the observed ATP increases. Similarly, the hypothesis indicates that positively charged surfaces will decrease metabolic activity, and results from studies of positively charged surfaces support this finding.