S160: Modulating the clostridial butanol (ABE) fermentation for higher product value

The acetone-butanol-ethanol (ABE) fermentation of solvent producing clostridia has been of interest for its application to fuel and chemical production from biomass. Improved yields and economics of the fermentation will be essential for large scale butanol production.  The coordination of butanol formation with cell physiology will be discussed in reference to enhancing the value of the fermentation. One route via improvement of the proportion of product that is butanol, has been examined via changes in culture conditions or genetic manipulations.  Another route is to also produce a compound of significant value as a co-product.  This avenue will be discussed considering riboflavin as a co-product.  The recovery of other value via coordination of activities within a biorefinery will also be discussed in terms of the options for redox the clostridia have in using the wide variety of carbon sources available for this metabolically versatile organism.