Alternating current influences anaerobic electroactive biofilm activity

Xin Wang, Lean Zhou, Lu Lu, Fernanda Leite Lobo, Nan Li, Heming Wang, Jaedo Park, Zhiyong Jason Ren

Research output: Contribution to journalArticle

29 Scopus citations

Abstract

Alternating current (AC) is known to inactivate microbial growth in suspension, but how AC influences anaerobic biofilm activities has not been systematically investigated. Using a Geobacter dominated 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.

Original languageEnglish (US)
Pages (from-to)9169-9176
Number of pages8
JournalEnvironmental Science and Technology
Volume50
Issue number17
DOIs
StatePublished - Sep 6 2016
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Environmental Chemistry

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