The demand for the inexpensive production of biofuels has
intensified due to increasing concerns of climate change, depletion
of petroleum-based fuels, and environmental problems. Ethanol is
one of the most promising alternative fuels with the potential to
reduce the problems caused by the enormous utilization of fossil
fuels. A key factor in the economy of ethanol production is the
choice of raw materials as feedstocks. Although ethanol has been
mainly produced from sucrose-containing feedstocks and starchy
materials, ethanol from lignocellulosic biomass has recently received
increasing attention due to the sustainable availability in
large quantities and the avoidance of the conflict with production
of food products (Festel, 2008; Zhu and Pan, 2010).