Open Access Original

Differential Gene Expression to Investigate the Effects of Low-level Electrochemical Currents on Bacillus subtilis

Robert Szkotak12, Tagbo H R Niepa12, Nikhil Jawrani12, Jeremy L Gilbert12, Marcus B Jones3 and Dacheng Ren1245*

Author Affiliations

1 Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, NY 13244, USA

2 Syracuse Biomaterials Institute, Syracuse University, Syracuse, NY 13244, USA

3 J. Craig Venter Institute, Rockville, MD 20850, USA

4 Department of Biology, Syracuse University, Syracuse, NY 13244, USA

5 Department of Civil and Environmental Engineering, Syracuse University, Syracuse, NY 13244, USA

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AMB Express 2011, 1:39  doi:10.1186/2191-0855-1-39

Published: 11 November 2011

Abstract

With the emergence and spread of multidrug resistant bacteria, effective methods to eliminate both planktonic bacteria and those embedded in surface-attached biofilms are needed. Electric currents at μA-mA/cm2 range are known to reduce the viability of bacteria. However, the mechanism of such effects is still not well understood. In this study, Bacillus subtilis was used as the model Gram-positive species to systematically investigate the effects of electrochemical currents on bacteria including the morphology, viability, and gene expression of planktonic cells, and viability of biofilm cells. The data suggest that weak electrochemical currents can effectively eliminate B. subtilis both as planktonic cells and in biofilms. DNA microarray results indicate that the genes associated with oxidative stress response, nutrient starvation, and membrane functions were induced by electrochemical currents. These findings suggest that ions and oxidative species generated by electrochemical reactions might be important for the killing effects of these currents.

Keywords:
Bacillus subtilis; bioelectric effect; biofilm, gene expression; electrochemical current