Oxygen suppresses light-driven anodic current generation by a mixed phototrophic culture

Darus, Libertus, Ledezma, Pablo, Keller, Jürg and Freguia, Stefano (2014) Oxygen suppresses light-driven anodic current generation by a mixed phototrophic culture. Environmental Science and Technology, 48 23: 14000-14006. doi:10.1021/es5024702


Author Darus, Libertus
Ledezma, Pablo
Keller, Jürg
Freguia, Stefano
Title Oxygen suppresses light-driven anodic current generation by a mixed phototrophic culture
Journal name Environmental Science and Technology   Check publisher's open access policy
ISSN 1520-5851
Publication date 2014-11-03
Sub-type Article (original research)
DOI 10.1021/es5024702
Volume 48
Issue 23
Start page 14000
End page 14006
Total pages 7
Place of publication Washington, DC, United States
Publisher American Chemical Society
Language eng
Abstract This paper describes the detrimental effect of photosynthetically evolved oxygen on anodic current generation in the presence of riboflavin upon illumination of a mixed phototrophic culture enriched from a freshwater pond at +0.6 V vs standard hydrogen electrode. In the presence of riboflavin, the phototrophic biomass in the anodic compartment produced an electrical current in response to light/dark cycles (12 h/12 h) over 12 months of operation, generating a maximum current density of 17.5 mA.m(-2) during the dark phase, whereas a much lower current of approximately 2 mA.m(-2) was generated during illumination. We found that the low current generation under light exposure was caused by high rates of reoxidation of reduced riboflavin by oxygen produced during photosynthesis. Quantification of biomass by fluorescence in situ hybridization images suggested that green algae were predominant in both the anode-based biofilm (55.1%) and the anolyte suspension (87.9%) with the remaining biovolume accounted for by bacteria. Genus-level sequencing analysis revealed that bacteria were dominated by cyanobacterium Leptolyngbia (∼35%), while the prevailing algae were Dictyosphaerium, Coelastrum, and Auxenochlorella. This study offers a key comprehension of mediator sensitivity to reoxidation by dissolved oxygen for improvement of microbial solar cell performance.
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2015 Collection
Advanced Water Management Centre Publications
 
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Created: Thu, 11 Dec 2014, 01:54:28 EST by Stefano Freguia on behalf of School of Chemical Engineering