Alternating electric fields induce a period-dependent motion of Escherichia coli in three-dimension near a conductive surface.
Alternating electric fields induce a period-dependent motion of Escherichia coli in three-dimension near a conductive surface.
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DOI：
10.1116/1.5078543
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发表时间：
2019-02
期刊：
影响因子：
2.1
通讯作者：
Xin Zhou;Meng Qi;Gui Huang;Chunfeng Ma;Lian-Jun Bao;Xiangjun Gong;Guangzhao Zhang;E. Zeng
中科院分区：
文献类型：
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作者：
Xin Zhou;Meng Qi;Gui Huang;Chunfeng Ma;Lian-Jun Bao;Xiangjun Gong;Guangzhao Zhang;E. Zeng
已证明电场可以最大限度地减少细菌的表面黏附，但它们如何影响近表面细菌的动态在很大程度上仍然被忽视。利用数字全息显微镜研究了交变电场作用下，大肠杆菌HCB1和HCB1414在导电表面附近的三维运动。交流场周期(T)对细菌近表面的行为模式有很大的影响，从而影响了大肠杆菌的表面粘附性。当T≥1 S时，Hcb1细胞频繁翻滚，与不加电场的情况相比，两株细胞都经历了更多的亚扩散运动。表面附近的细菌密度因趋电性而变化，这取决于表面的初始极化。在较短的时间内(T≤0.1%，S)，电场既可以作为阳极，也可以作为阴极，使近表面的细菌密度降低10%-20%。交流场直接干扰细菌的固有旋转。在T≥1 S，菌体表现出强烈的摆动。随着T的降低，这种摆动被抑制，从而减少了大肠杆菌与表面的碰撞，从而导致细菌密度下降。这些结果表明，使用T可调的低密度交流电场可能是一种很有前途的防污策略，值得进一步研究。
It has been demonstrated that electric fields can minimize surface adhesion of bacteria, but how they affect the near-surface bacterial dynamics has remained largely overlooked. In the present study, the three-dimensional motions of Escherichia coli (E. coli) HCB1 and HCB1414 near a conductive surface under alternating-current (AC) electric fields were monitored with digital holographic microscopy. The period (T) of AC fields exhibited profound effects on near-surface bacterial behavioral patterns and thus affected the surface adhesiveness of E. coli. When T ≥ 1 s, HCB1 cells tumble frequently, and both two strain cells increasingly undergo subdiffusive motions compared to the case without electric fields. The bacterial density near the surface varies due to galvanotaxis depending on the initial polarization of the surface. For shorter periods (T ≤ 0.1 s), the electric fields reduce the near-surface bacterial density by 10%-20% with the surface as either an anode or a cathode. The AC fields directly disturb the intrinsic bacterial rotation. The bacterial body exhibits strong wobbling at T ≥ 1 s. Such wobbling was suppressed with decreasing T, which reduces the collisions between E. coli and the surface and thus leads to declining bacterial density. These results suggest that the use of low-density AC fields with tunable T may be a promising antifouling strategy and merits further investigations.