Microbial Electrochemical Cells (mxcs)
Microbial Electrochemical Cells (MXCs) hold microbiological and technological advantages for producing renewable energy sources from complex organic compounds and wastes. Our ability to increase electron recoveries from fermentable substrates is limited by our lack of a deep understanding of the interactions among the key microbes involved in the process, i.e., Anode Respiring Bacteria (ARB), fermenters, methanogens, and acetogens. For MXC research, our lab has three main foci: 1) enhancing ARB syntrophic interactions in order to maximize current densities and reduce electron losses to unwanted sinks, such as methane or fermentation products not metabolized by ARB, 2) bioprospecting, or looking for novel/better ARB in the environment, and 3) linking community structure to community function.
Cyanobacteria are photosynthetic bacteria that grow using energy from freely available sunlight and carbon dioxide. Biomass from the cyanobacteria can be used as a feedstock for sustainable production of biodiesel and other biofuels. Our team grows the model cyanobacterium Synechocystis sp. PCC 6803 in photobioreactors (PBRs) to produce biomass that can be converted into biofuels. However, heterotrophic bacteria also grow in PBRs along with Synechocystis sp. PCC 6830, especially at large scales, where sterile or aseptic maintenance of the PBR cultures is impractical. In natural settings, heterotrophic bacteria are almost always associated with cyanobacteria and can provide important benefits to the cyanobacteria. Conversely, some heterotrophic bacteria can negatively affect the growth of cyanobacteria. We seek to understand the different types of heterotrophic bacteria associated with PBR cultures of Synechocystis sp. PCC 6803 and how these heterotrophic bacteria affect the growth of Synechocystis sp. PCC 6803. Our ultimate goal is to develop techniques to effectively monitor and manage PBR microbial communities in a way that maximizes the positive effects of the heterotrophic bacteria in order to improve biomass production by Synechocystis sp. PCC 6803 while minimizing any negative impacts the heterotrophic bacteria may have.