The effect of biofilm thickness on electrochemical activity of Geobacter sulfurreducens. (5th October 2016)

• Record Type: Journal Article
• Authors: Sun, Dan; Chen, Jie; Huang, Haobin; Liu, Weifeng; Ye, Yaoli; Cheng, Shaoan
• Is Part Of: International journal of hydrogen energy. Volume 41:Number 37(2016)
• Page Start: 16523
• Page End: 16528
• Publication Date: 2016-10-05
• Subjects: Geobacter sulfurreducens -- Electrochemical performance -- Metabolic spatial variability -- Biofilm thickness -- Biofilm biomass; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2016.04.163
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: It is widely believed that the high electrochemical performance of Geobacter sulfurreducens relies on its thick and conductive biofilms in bioelectrochemical systems. However, in this study, the G. sulfurreducens biofilm reached the highest electrochemical activity with a biofilm thickness of ∼20 μm, and then the electrochemical activity decreased with increasing thickness until the biofilm growth ceased at a thickness of ∼45 μm. The electrochemical analysis and the metabolic spatial variability showed that in the first 5 cycles the live cells grew fast, which led to a rapid drop of charge transfer resistance and further contributed to high current generation, however, from cycle 5 to 12, a great many inactive cells accumulated in the inner layer of biofilm, which resulted in high diffusion resistance. Thus, although the G. sulfurreducens can always form thick biofilms, its highest electrochemical activity reached at a much thinner thickness, suggesting that the live-cell mass rather than the biofilm thickness is responsible for the high current generation. Highlights: The G. sulfurreducens biofilm at the highest electrochemical activity was much thinner than the final biofilm. Fast accumulation of inactive cells caused the lower current generation in the thick biofilm. Highly effective biofilm required for high absolute-mass and relative-ratio of live cells rather than thick thickness.