S145: Microbial Electrosynthesis: Co-utilization of substrates and carbon dioxide

One of the main challenges in the biofuels and biochemicals industry is the efficient conversion of fermentable sugar to product.  As a consequence, efforts to increase product yield are seen as vital to the commercialization of these processes.  Using electrodes as a source of electrons for incorporation into the cellular metabolism has been suggested as a way to drive carbon fixation and improve efficiencies in the overall conversion of conversion of carbon dioxide to industrially important fuels and chemicals.  However, obtaining extracellular electron transfer large enough to drive carbon fixation remains a challenge.  Therefore, a number of groups have been focused on optimizing this membrane associated process for carbon fixation.    However, a number of carboxylation reactions are present in heterotrophic organisms.  Exploiting these reactions and incorporating other carbon fixing steps in the presence of fermentable substrates and an extracellular electron source may make it possible to circumvent the large surface areas that would be required for bioelectrosynthesis using carbon dioxide as the sole carbon source.  This strategy may be particularly useful for highly reduced products or those that require a several reducing steps.  We will present our analysis of this integrated approach to electrobiosynthesis for the production of chemicals.