The performance of a cyanobacterial biomass-based microbial fuel cell (MFC) inoculated with Shewanella oneidensis MR-1

Cyanobacterial biomass is a rich renewable resource for direct bioelectricity generation in biomass-based microbial fuel cells (MFCs). In this study, the performance of a double chamber MFC with Anabaena vaginicola cyanobacterial biomass as the anodic substrate was investigated. The anode chamber was inoculated with a pure culture of Shewanella oneidensis MR-1, and different MFC experiments using pretreated and untreated cyanobacterial biomass substrate with 5 or 20 mg/L riboflavin were conducted. Pretreatment of the biomass and addition of 20 mg/L riboflavin led to the highest current density (366 mA/m(3)), maximum power density (144 mW/m(3)), chemical oxygen demand removal efficiency (65%), and coulombic efficiency (5.7%). Increasing the concentration of riboflavin improved bioelectricity generation (1.4-1.7-fold increase in maximum power density), confirming its effectiveness as a redox mediator, and its role in the extracellular electron transfer process of the S. oneidensis MR-1 biofilm. Moreover, pretreating the biomass also enhanced the conversion efficiency of biomass to bioelectricity. This indicated that pretreatment of the biomass influenced the utilization of biomass by S. oneidensis MR-1 cells. These findings can help increasing the potential of using renewable substrates for more efficient bioenergy generation in pure culture MFCs.

Automated summary

Using Anabaena vaginicola cyanobacterial biomass as the anodic substrate in double chamber MFCs can improve bioelectricity generation through pretreatment of the biomass and addition of riboflavin. Pretreatment and addition of riboflavin can increase maximum power density, and enhance the utilization efficiency of biomass by S. oneidensis MR-1 cells.