Metagenomics revealing biomolecular insights into the enhanced toluene removal and electricity generation in PANI@CNT bioanode

Abstract

Microbial fuel cells (MFCs) have significant potential for environmental remediation and energy recycling directly from refractory aromatic hydrocarbons. To boost the capacities of toluene removal and the electricity production in MFCs, this study constructed a polyaniline@carbon nanotube (PANI@CNT) bioanode with a three-dimensional framework structure. Compared with the control bioanode based on graphite sheet, the PANI@CNT bioanode increased the output voltage and toluene degradation kinetics by 2.27-fold and 1.40-fold to 0.399 V and 0.60 h−1, respectively. Metagenomic analysis revealed that the PANI@CNT bioanode promoted the selective enrichment of Pseudomonas, with the dual functions of degrading toluene and generating exogenous electrons. Additionally, compelling genomic evidence elucidating the relationship between functional genes and microorganisms was found. It was interesting that the genes derived from Pseudomonas related to extracellular electron transfer, tricarboxylic acid cycle, and toluene degradation were upregulated due to the existence of PANI@CNT. This study provided biomolecular insights into key genes and related microorganisms that effectively facilitated the organic pollutant degradation and energy recovery in MFCs, offering a novel alternative for high-performance bioanode.