Bioelectrochemical application of an F. uniseptata pigment in a microbial fuel cell for electricity generation.

Abstract

In this work, the isolation and identification of pigment-producing fungi from substrate samples collected in the Sonoran Desert, Mexico, are described. Three fungal isolates, named CR2, SM1, and GBS, were selected for their ability to produce colored pigments. The redox properties of these pigments were characterized using UV-Vis spectroscopy and cyclic voltammetry. The GBS pigment, produced by the fungus Forliomyces uniseptata, exhibited the best electrochemical behavior, with a reversible redox cycle, indicating its potential as a redox mediator (RM) for microbial fuel cells (MFCs). The effect of different light wavelengths on the growth kinetics of F. uniseptata and pigment production was evaluated. Blue light moderately accelerated pigment biosynthesis, while darkness promoted fungal growth. Finally, the GBS pigment was tested as a RM in a MFC inoculated with Bacillus subtilis. A maximum power density of 37 μW/cm². It is suggested that mass transfer could limit performance.