ARS | Publication request: Effect of cellulosic sugar degradation products (furfural and hydroxymethylfurfural) on acetone-butanol-ethanol (ABE) fermentation using Clostridium beijerinckii P260

Submitted to: Journal of Food and Bioproducts Processing
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 28, 2011
Publication Date: July 2, 2012
Citation: Qureshi, N., Bowman, M.J., Saha, B.C., Hector, R.E., Berhow, M.A., Cotta, M.A. 2012. Effect of cellulosic sugar degradation products (furfural and hydroxymethylfurfural) on acetone-butanol-ethanol (ABE) fermentation using Clostridium beijerinckii P260. Journal of Food and Bioproducts Processing. 90:533-540.

Interpretive Summary: Butanol is a superior biofuel to ethanol and can be produced from agricultural crop residues such as wheat, barley and rice straws, and corn stover. All these feedstocks require chemical and physical pretreatment and hydrolysis to break down cellulosic and hemicellulosic components to sugars before they are converted to butanol. During this breakdown process, certain additional components are also produced that can either retard or enhance the rate of butanol production by fermentation. It was discovered that hydrolyzed wheat straw produces fermentation- enhancing components that increase this rate over 200%. Such an increase in fermentation rate would economically benefit the process of biofuel butanol production from this feedstock. Based on these investigations, further studies are underway to identify the level of these components that are present in corn stover hydrolyzate. These studies are aimed to benefit U.S. farmers and the biofuel industry.

Technical Abstract: Studies were performed to identify chemicals present in wheat straw hydrolysate (WSH) that enhance acetone butanol ethanol (ABE) productivity. These chemicals were identified as furfural and hydroxymethyl furfural (HMF). Control experiment resulted in the production of 21.09-21.66 gL**-1 ABE with a productivity of 0.29-0.30 gL**-1h**-1. WSH contained 0.04-0.34 gL**-1 furfural and 0.12–0.88 gL**-1 HMF. Furfural at a concentration of 0.50 gL**-1 resulted in a productivity of 0.88 gL**-1h**-1 which is 293% of the productivity obtained in control experiments. Supplementation with 1.00 gL**-1 HMF into the fermentation medium produced 25.27 gL**-1 ABE with a productivity of 0.68 gL**-1h**-1. An increase in productivity of this magnitude would reduce capital and operational cost of an ABE plant significantly. Both furfural and HMF enhanced specific productivity (275-308%) of ABE. In brief, WSH contained an adequate concentration of furfural and HMF that enhanced ABE productivity, specific productivity, and product concentration. This is the first report on identification of chemicals present in WSH that enhance ABE productivity.