Pioneer the Physical Chemistry of Biological Electron Transfer based on Bacterial Ext racellular Electron Transport

Microbes with the capability of extracellular electron transport (EET) were firstly discovered by environmental microbiologists more than 25 years ago. EET has been considered as unique and special phenomenon for the discovered microbes. However, by revealing its molecular mechanism with our developed new electrochemical techniques to monitor, control, and optimize biological electron flow, we found that EET is highly general phenomenon in the nature to sustain the ecosystems, and is controllable to use in various applications.

Prior to our study, EET had been a microbial phenomenon lacked the molecular-level mechanism based on physical chemistry. We developed highly sensitive electrochemical techniques to monitor the dynamic of electron and cation transport process in intact microbial cells. The novel techniques and knowledge expanded the view for microbial anaerobic respiration associate with the EET. EET associate with substrate-level ATP synthesis, which is hybrid of respiratory electron transport chain and fermentative energy conservation, which potentially open up new technology for metabolic engineering to drastically enhance the rate of fermentation reactions. Also, electron can be a sole energy source for microbial growth, which defines the microbes as “Electrolithoautotroph”, the third type of primary producer. Furthermore, we have pioneered several techniques to control microbial activity and physiology. For instance, we can deactivate the anaerobic iron corrosion induced by EET microbes by simply electrochemical poising. Also, we can even regulate the circadian clock of cyanobacteria, which lack the capability of EET, via electric perturbation using newly developed biocompatible redox polymer. The generality and impacts of EET in nature has just started to be recognized in the society of microbiology and physical chemistry. Given the fact that life is the material organized by electron flow, our research on EET based on the knowledge of physical chemistry will lead to new scientific discovery and practical applications in the near future.