Utilizing black yeast for sustainable solutions: Pioneering clean energy production and wastewater treatment with Exophiala dermatitidis

A single-chamber microbial fuel cell (MFC) was constructed to assess the capacity of Exophiala dermatitidis EXF8193 as an electron-donating microorganism. Unidirectional carbon fiber electrodes were used, and voltage generation was monitored over 120 hours. The system achieved a maximum voltage of 176 mV after 93 hours of operation. Simultaneously, the decolorization of Basic Blue 9 (BB9) dye was evaluated, achieving 70% degradation within 120 hours. Initial optimization studies focused on individual variables, including carbon source, anode shape, and anodic surface area. Results indicated that glucose, a T-shaped anode, and an anodic area of 12 cm2 were optimal, yielding voltage values of 175.8 +/- 0.57 mV, 175.8 +/- 0.57 mV, and 310.53 +/- 1.22 mV, respectively. In the second stage, a multiparametric optimization was conducted using Response Surface Methodology (RSM) with a Box-Behnken design, resulting in a second-order model with an R2 of 91.7. Under optimized conditions, the MFC reached a favorable maximum voltage of 284 mV, demonstrating enhanced performance with fine-tuned operational parameters. These findings represent a pioneering step in exploring black yeast, particularly E. dermatitidis, as a sustainable bio-catalyst in MFC technology. This study opens new avenues for further research on extremophilic fungi in bioenergy production and wastewater treatment, highlighting the need for continued exploration of black yeast's unique properties in biotechnological applications.