Enhanced photocurrent production by the synergy of hematite nanowire-arrayed photoanode and bioengineered Shewanella oneidensis MR-1

Biosens Bioelectron. 2017 Aug 15:94:227-234. doi: 10.1016/j.bios.2017.03.006. Epub 2017 Mar 8.


Coupling the light-harvesting capabilities of semiconductors with the catalytic power of bacteria is a promising way to increase the efficiency of bioelectrochemical systems. Here, we reported the enhanced photocurrents produced by the synergy of hematite nanowire-arrayed photoanode and the bio-engineered Shewanella oneidensis MR-1 in a solar-assisted microbial photoelectrochemical system (solar MPS) under the visible light. To increase the supply of bioelectrons, the D-lactate transporter, SO1522, was overexpressed in the recombinant S. oneidensis (T-SO1522) that could digest D-lactate 61% faster than the wild-type S. oneidenesis. Without light illumination, the addition of either the wild-type or the recombinant S. oneidensis to the system did not induce any obvious increase in the current output. However, under one-sun illumination, the photocurrent of the abiotic control was 16±2 μA cm-2 at 0.8V vs. Ag/AgCl, and the addition of the wild-type S. oneidensis and the recombinant S. oneidensis increased the photocurrent to 70±6 and 95±8 μA cm-2, respectively, at 0.8V vs. Ag/AgCl. Moreover, the solar MPS with T-SO1522 presented quick and repeatable responses to the on/off illumination cycles, and had relatively stable photocurrent generation in the 273-h operation. Scanning electron microscope (SEM) images showed that the cell density on the hematite photoelectrode was similar between the recombinant and the wild-type S. oneidensis. These findings revealed the pronounced influence of metabolic rates on the light-to-electricity conversion in the complex photocatalyst-electricigen hybrid system, which is important to promote the development of the solar MPS for electricity production and wastewater treatment.

Keywords: Bio-engineered Shewanella oneidensis MR-1; Bioelectron supply; Hematite nanowire-arrayed photoelectrode; Light-to-electricity conversion; Solar-assisted microbial photoelectrochemical system.

MeSH terms

  • Bioelectric Energy Sources*
  • Biosensing Techniques / methods*
  • Lactic Acid / chemistry
  • Light
  • Microscopy, Electron, Scanning
  • Nanowires / chemistry*
  • Shewanella / chemistry*
  • Shewanella / metabolism
  • Wastewater / microbiology


  • Waste Water
  • Lactic Acid