Team:LZU-China/wetlab

         Why did we choose the MFC as our device? MFC is an abbreviation of microbial fuel cell.MFC is a bioreactor that can convert biomass energy into electricity through the metabolic activity of bacteria in the anode chamber.(Du, Li, & Gu, 2007) . Nowadays, MFC is a new energy source available for us to solve pollution problem and produce electricity energy simultaneously.

         However, the main challenge of MFC is how to bring these technologies out of the laboratory and engineer practical systems for bioenergy production at larger scales. One of the most severe problems is the low efficiency of extracellular electron transfer without the help of redox mediators added manually into the reactor, such as neutral red, thionin (Rabaey & Verstraete, 2005) . The addition of these mediators seemed to be another troublesome pollutant to deal with.

         In our study, we successfully constructed a power stimulating model to solve this puzzle. We use Shewanella, a well-known star of electricity-producing bacteria family, as our devices’ powerful engine, it can send forth bacterial nanowires and reach the highest power output peak. Furthermore, we construct an extraordinary “Turbo Boost” device—genetically modified E.coli system—to stimulate this process. The hero of this story is riboflavin, a natural redox mediator also known as Vitamin B2. Our E.coli system can produce a certain amount of riboflavin, which concentration is dependent on substrate’s quantity, using a pollutant substrate bio-sensor coupling riboflavin synthetic gene cluster.

         In that system, we can monitor pollutant concentration real-timely by measuring the voltage of MFC devices and demonstrate result via data processing center and mobile network application.