Alternating Current Influences Anaerobic Electroactive Biofilm Activity
Alternating Current Influences Anaerobic Electroactive Biofilm Activity
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交流电影响厌氧电活性生物膜活性
DOI：
10.1021/acs.est.6b00813
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发表时间：
2016
影响因子：
11.4
通讯作者：
Ren Z. J.
中科院分区：
文献类型：
--
作者：
Wang X.;Zhou L.;Lu L.;Lobo F. L.;Li N.;Wang H.;Park J.;Ren Z. J.
交流电可以抑制微生物在悬浮液中的生长，但交流电如何影响厌氧生物膜活性还没有系统的研究。以生长在微生物电化学反应器电极上的以土细菌为主的厌氧生物膜为研究对象，研究发现1 MHz ~ 1 kHz的高频交流电（振幅为5 V，30 min）对生物膜活性仅表现出短暂的抑制作用。而低频（100 Hz、1.2或5 V）处理导致同一生物膜上的极限电流永久性下降47 ± 19%，这归因于电流体动力的作用，导致生物膜损伤和细胞间电子传递网络的丢失。共聚焦显微镜图像显示这种失活主要发生在生物膜和电极之间的界面处。将频率进一步降低到1 Hz导致水电解，产生气泡，将所有附着的细胞从电极中冲洗出来。这些发现为理解和调控生物膜生长提供了新的参考，这在生物污染控制、厌氧废物处理、能源和产品回收以及微生物生态学和生理学的一般理解方面具有更广泛的意义。
Alternating current (AC) is known to inactivate microbial growth in suspension, but how AC influences anaerobic biofilm activities has not been systematically investigated. Using aGeobacterdominated anaerobic biofilm growing on the electrodes of microbial electrochemical reactors, we found that high frequency AC ranging from 1 MHz to 1 kHz (amplitude of 5 V, 30 min) showed only temporary inhibition to the biofilm activity. However, lower frequency (100 Hz, 1.2 or 5 V) treatment led to 47 ± 19% permanent decrease in limiting current on the same biofilm, which is attributed to the action of electrohydrodynamic force that caused biofilm damage and loss of intercellular electron transfer network. Confocal microscopy images show such inactivation mainly occurred at the interface between the biofilm and the electrode. Reducing the frequency further to 1 Hz led to water electrolysis, which generated gas bubbles that flushed all attached cells out of the electrode. These findings provide new references on understanding and regulating biofilm growth, which has broader implications in biofouling control, anaerobic waste treatment, energy and product recovery, and general understanding of microbial ecology and physiology.