Fully reversible current driven by a dual marine photosynthetic microbial community

Bioresour Technol. 2015 Nov:195:248-53. doi: 10.1016/j.biortech.2015.06.055. Epub 2015 Jun 17.

Abstract

The electrochemical activity of two seawater microbial consortia were investigated in three-electrode bioelectrochemical cells. Two seawater inocula - from the Sunshine Coast (SC) and Gold Coast (GC) shores of Australia - were enriched at +0.6 V vs. SHE using 12/12 h day/night cycles. After re-inoculation, the SC consortium developed a fully-reversible cathodic/anodic current, with a max. of -62 mA m(-2) during the day and +110 mA m(-2) at night, while the GC exhibited negligible daytime output but +98 mA m(-2) at night. Community analysis revealed that both enrichments were dominated by cyanobacteria, indicating their potential as biocatalysts for indirect light conversion to electricity. Moreover, the presence of γ-proteobacterium Congregibacter in SC biofilm was likely related to the cathodic reductive current, indicating its effectiveness at catalysing cathodic oxygen reduction at a surprisingly high potential. For the first time a correlation between a dual microbial community and fully reversible current is reported.

Keywords: Biophotovoltaics; Cathodic current; Microbial solar cell; Reversible current; γ-Proteobacterium Congregibacter.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Australia
  • Bacteria / metabolism
  • Biocatalysis
  • Bioelectric Energy Sources / microbiology*
  • Biofilms
  • Electricity*
  • Electrochemical Techniques
  • Electrodes
  • Oxidation-Reduction
  • Oxygen / metabolism
  • Photosynthesis*
  • Seawater / microbiology*

Substances

  • Oxygen