Enhancing the performance of microbial fuel cell using a carbon-fiber-brush air cathode with low-cost mushroom Ganoderma laccase enzyme

A novel carbon-fiber-brush air cathode microbial fuel cell (MFC) with low-cost mushroom Ganoderma laccase enzyme was used to treat molasses wastewater. Experimental results indicate that the laccase activity of Ganoderma lucidum was considerably greater than Pleurotus eryngii and Simplicillium obclavatum. The maximal laccase activity (108 U/L) was reached in the presence of 125 mu M of CuSO4 on day eight. Adding the laccase broth to the cathode clearly enhanced the MFC performance. The MFC with crude laccase broth generated more electricity (420 mV) than with filtered broth (300 mV). Increasing the liquid level of the cathode and increasing the sets of cathodes increased the generation of electricity. Under optimal operational conditions, a power density of 40 mW cm(2) was achieved and the MFC effectively maintained the power generation as long as 45 days. DGGE profile and dendrogram analysis were also used to investigate the microbial community structure in the anode chamber. (C) 2017 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.