Sunday, August 1, 2010
Pacific Concourse (Hyatt Regency San Francisco)
Ethanol produced from lignocellulosic biomass is a promising renewable alternative to diminishing oil and gas liquid fuels. The release of three new sugarcane varieties, L 79-1002, HoCP 91-552 and Ho 00-961, to be used as bioenergy crops is a promising feedstock alternative. As sugarcane is an important industry in Louisiana, “energy cane” has great potential to sustain a competitive sugarcane industry. Lignocellulosic biomass consists of a network of cellulose and hemicellulose bound by lignin. The process of converting lignocellulosic biomass to ethanol involves pretreatment to disrupt the complex of lignin, cellulose, and hemicellulose, freeing sugars for enzymatic saccharification and fermentation. Determining optimal pretreatment techniques and fermentative organisms is essential to determining which energy cane has the greatest potential for bioethanol production. The purpose of this study was to evaluate energy cane for lignocellulosic ethanol production. Energy cane varieties L 79-1002 (type II) and HoCP 91-552 (type I), as well as commercial sugarcane variety HoCP 96-540, were pretreated with alkaline peroxide and also sulfuric acid solutions. Pretreated biomass was fermented using Saccharomyces cerevisiae 916, Saccharomyces cerevisiae 765, Escherichia coli, Zymomonas mobilis, and Klebsiella oxytoca. Evaluation of type I and type II energy cane and commercial sugarcane for lignocellulosic ethanol production revealed that type II energy cane variety L 79-1002 pretreated with 1.4 M sulfuric acid and fermented by K. oxytoca produced the most ethanol. The use of enzymes significantly improved ethanol yield of type II energy cane. These new energy cane varieties are promising for future lignocellulosic ethanol production.