Monday, August 13, 2012
Columbia Hall, Terrace Level (Washington Hilton)
Transportation fuels produced from lignocellulosic biomass have a demonstrated potential to substitute for traditional fossil fuel. Cellulosic biomass is renewable and represents the largest quantity of organic material on earth. The U.S DOE has projected that approximately 1.3 billion dry tons of lignocellulosic could be available annually. Sorghum bicolor, a drought tolerant grass from sub-saharan Africa offers many advantages as a potential biofuel feedstock crop including: high levels of drought tolerance, lower market price, and the ability to assimilate carbon at higher temperatures as well as low water conditions. In addition, sorghum is closely related to sugarcane and maize and may act as a model species for identification of genes and traits associated with increased bioenergy production. The cell wall constituents: cellulose, hemicellulose, proteins, and lignin exist in varied amounts across the Sorghum genus. As such, different varieties of sorghum yield different ratios of reduced sugars following enzymatic hydrolysis. The aim of this study was to evaluate a panel of sixteen genetically diverse sorghum varieties to determine which were the most amiable to fermentation to butanol, a gasoline substitute, using Clostridium beijerinckii. Identification of varieties with higher normalized fermentation yields can be candidate parents of mapping populations to discover biofuel fermentation yield-enhancing genes. Initial results indicate the lack of correlation between total sorghum hydrolysate yield (sugars) and butanol yield (fermentation products). As such, efforts will be made to determine if a correlation between genotype and fermentation yield as butanol exists which could be applied to a species wide panel of Sorghum bicolor.