Electro-polarization of protein-like substances accelerates trans-cell-wall electron transfer in microbial extracellular respiration
Qilin Yu,
Haohao Mao,
Bowen Yang,
Yahui Zhu,
Cheng Sun,
Zhiqiang Zhao,
Yang Li,
Yaobin Zhang
Affiliations
Qilin Yu
Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
Haohao Mao
Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
Bowen Yang
Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
Yahui Zhu
Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
Cheng Sun
Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
Zhiqiang Zhao
Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
Yang Li
School of Ocean Science and Technology, Dalian University of Technology, Panjin, Liaoning 124221, China
Yaobin Zhang
Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China; Corresponding author
Summary: Electrical stimulation has been used to strengthen microbial extracellular electron transfer (EET), however, the deep-seated reasons remain unclear. Here we reported that Bacillus subtilis, a typical gram-positive bacterium capable of extracellular respiration, obtained a higher EET capacity after the electrical domestication. After the electrical domestication, the current generated by the EET of B. subtilis was 23.4-fold that of the control group without pre-domestication. Multiple lines of evidence in bacterial cells of B. subtilis, their cell walls, and a model tripeptide indicated that the polarization of amide groups after the electrical stimulation forwarded the H-bonds recombination and radical generation of protein-like substances to develop extracellular electron transfer via the proton-coupled pattern. The improved electrochemical properties of protein-like substances benefited the trans-cell-wall electron transfer and strengthen extracellular respiration. This study was the first exploration to promote microbial extracellular respiration by improving the electrochemical properties of protein-like substances in cell envelopes.
