Neutral red-mediated microbial electrosynthesis by Escherichia coli, Klebsiella pneumoniae, and Zymomonas mobilis

Bioresour Technol. 2015 Nov:195:57-65. doi: 10.1016/j.biortech.2015.06.005. Epub 2015 Jun 11.

Abstract

The aim of this work was to compare the effects of electrosynthesis on different bacterial species. The effects of neutral red-mediated electrosynthesis on the metabolite profiles of three microorganisms: Escherichia coli, Klebsiella pneumoniae, and Zymomonas mobilis, were measured and compared and contrasted. A statistically comprehensive analysis of neutral red-mediated electrosynthesis is presented using the analysis of end-product profiles, current delivered, and changes in cellular protein expression. K. pneumoniae displayed the most dramatic response to electrosynthesis of the three bacteria, producing 93% more ethanol and 76% more lactate vs. control fermentation with no neutral red and no electron delivery. Z. mobilis showed no response to electrosynthesis except elevated acetate titers. Stoichiometric comparison showed that NAD(+) reduction by neutral red could not account for changes in metabolites during electrosynthesis. Neutral red-mediated electrosynthesis was shown to have multifarious effects on the three species.

Keywords: Bioelectrochemical system; Electron transfer; Electrosynthesis; Neutral red.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Batch Cell Culture Techniques
  • Bioelectric Energy Sources / microbiology*
  • Electrochemical Techniques
  • Electrons
  • Escherichia coli / growth & development
  • Escherichia coli / metabolism*
  • Fermentation
  • Klebsiella pneumoniae / growth & development
  • Klebsiella pneumoniae / metabolism*
  • Neutral Red / metabolism*
  • Zymomonas / growth & development
  • Zymomonas / metabolism*

Substances

  • Neutral Red