Tuesday, May 1, 2012
Napoleon Ballroom C-D, 3rd fl (Sheraton New Orleans)
Our need for alternative and cleaner liquid fuel is ever growing because of the dwindling supply and increased price of oil for the past ten years. Lignocellulosic ethanol production is an attractive option to meet the demand of energy for the transportation sector of our country. The production of ethanol from gamagrass and switchgrass is very attractive because it grows very well in the wet and marshy environment that is common to southeast Louisiana. Gamagrass is also a native perennial grass, which is commonly found in Louisiana and eastern United States. Gamagrass grows on marginal land and will not take up the valuable agricultural land for energy production. The purpose of this study was to demonstrate locally grown gamma grass could be effectively used to produce ethanol. We optimized pre-treatment conditions to remove lignin and also effectively used enzymes, cellulase and xylanase to produce glucose and xylosic sugars from cellulose and hemicellulose components of gamagrass. These sugars were used for fermentation with a recombinant E.coli FBR 5 capable of fermenting glucose and xylose simultaneously. The results indicated that the use of cellulase enzyme produced 2,356 mg/L ethanol and the use of xylanase enzyme yielded 1,301 mg/L ethanol. The enzyme cocktail of cellulase and xylanase produced the maximum ethanol yield of 6,002 mg/L within nine days of fermentation. Further studies are needed to scale up the fermentation process to pilot scale and eventually commercial scale to meet the energy demand of our country.