Roles of Biofilm Structure and Functional Genes in Overcoming Limited Dimethyl Sulfide Degradation and Energy Recovery

Dimethyl sulfide (DMS) which features poor solubility and an odorous smell is crucial to eliminate for a suitable living environment. Taking advantage of the interaction between microorganisms and electrodes, the microbial fuel cell (MFC) can realize simultaneous DMS degradation and electricity recovery. Herein, to overcome the limited rates of degradation and energy recovery caused by the toxicity of DMS, an electroactive biofilm is developed inside a porous polyaniline@carbon nanotube (PANI@CNT) electrode. The degradation kinetics of the resulted PANI@CNT bioanode (0.14 h(-1)) increases by 2.8-fold compared with the control bioanode. Meanwhile, the maximum power density attains 319.23 mW m(-2), which is on the same order of magnitude as the MFCs driven by easily degradable substrates in the literature. The homogeneous biofilm with an average viability as high as 88.6% proves that the porous structure of PANI@CNT could promote the internal and external diffusion in the biofilm. Furthermore, the metagenomic analysis indicates that the enriched functional genes for DMS metabolism also contribute to overcome the limitations caused by the toxic property of DMS. These findings provide a good alternative for rapid DMS degradation and efficient power generation and demonstrate the underlying mechanism.