Development of wheat straw based catholyte for power generation in microbial fuel cell

Abstract

Microbial fuel cell has been extensively used for electricity generation. A dual chambered microbial fuel cell was designed to degrade wheat straw by white rot fungi, Phlebia floridensis and Phlebia brevispora in cathode chamber. Pichia fermentans was used as exoelectrogenic yeast in anodic chamber. Lignocellulolytic enzymes including cellulase and laccase were efficiently produced by both the fungi in cathode chamber during 30 days of experiment. Concentrations of reducing sugars and phenolics in the catholyte increased during wheat straw degradation. Maximum laccase (9.035 CU ml−1) was produced by P. floridensis and a maximum open circuit voltage (0.504 V) was achieved on 9th day. P. brevispora produced maximum laccase upto 4.77 CU ml−1 and maximum open circuit voltage (0.496 V) was recorded on 17th day. Power density followed the pattern of open circuit voltage and a maximum power density of 33.19 mW m−2 and 12.90 mW m−2 was achieved by P. floridensis and P.brevispora, respectively. The degradation of wheat straw improved the efficiency of catholyte by improving electricity generation in a yeast fuel cell. Thus, the setup explores the potential of agricultural waste to be used in such sustainable and eco-friendly technology to produce bio-electricity.