This Small Business Innovation Research Phase I project will develop a process to increase the productivity and yield of biobutanol from cultures of solvent-forming Clostridium by treating cultures with recently discovered Clostridium quorum-sensing molecules. The biobutanol fermentation can be difficult to operate due to changes in the producing bacteria driven by unknown biological mechanisms, which result in "stuck" or "degenerate" cultures that don?t produce butanol. As the proportion of unproductive bacteria increases biobutanol productivity drops, yield from starting materials decreases and process economics suffer. Previously undescribed biological mechanisms in Clostridium that are involved in controlling the ability to make biobutanol have recently been discovered. An application of that discovery can prevent stuck or degenerated biobutanol fermentations and increase productivity and yield. Consequently, investment and operating costs for a biobutanol fermentation facility will decrease, and annual revenues will increase. Phase 1 research will focus on optimizing culture treatment levels with quorum-sensing molecules, and obtaining biobutanol yield and productivity data for batch and continuous cultures. The broader/commercial impacts of this research are that as a second generation biofuel, biobutanol produced by Clostridium can use a broader range of substrates than bioethanol production, and has significant advantages over bioethanol as a fuel and industrial chemical for which demand is increasing. New companies are engaged in improving biobutanol fermentation processes and in genetic engineering to improve biobutanol formation. A new understanding of biological mechanisms that regulate Clostridium biobutanol biosynthesis, however, has the potential to generate transformative technology for the biobutanol fermentation industry