Tuesday, May 1, 2012
Napoleon Ballroom C-D, 3rd fl (Sheraton New Orleans)
Both rising environmental awareness and the decline of fossil fuel reserves have been a driving force for the development of biorefineries in the last decade. Such integrated plants could competitively produce fuels, valuable chemicals and other materials. In pulp and paper mills or wood based energy industries, the hemicellulose fraction of wood is currently under- utilized. Hemicellulose can effectively be recovered by hot water extraction from wood chips prior to pulp or cellulose production. Hot water pre-treatment of hardwoods is a self-catalytic process which essentially results in solubilized oligomers, an attractive candidate for the fermentative production of organic acids, such as succinic acid. However, in addition to xylan, significant amounts of acetic acid are released and depending on extraction conditions degradation of lignin and xylan will yield phenolics and furfural. These compounds are known to have an inhibitorial effect on a number of microorganisms and therefore their impact on the selected fermentation need to be considered.
In this study the effects of acetic acid, furfural and hydrobenzoic acid (model compound for phenolics) on the growth and fermentation performance of Escherichia coli were investigated. The aim was to determine the detoxification requirements for this bacterium and to minimize the pretreatment costs prior to succinic acid production by fermentation of hardwood hemicellulose.