For example, straw has been used extensively as a raw mate- rial for pulp and paper in countries that have a shortage of wood resources. Nevertheless, it has been difficult to recover chemicals in black liquor because of the high silica content of rice straw, with a consequence of water pollution (Pan et al., 1999). Rice straw is also an important forage for ruminants in many riceproducing countries. However the cuticle wax silica layer of the straw stem is a barrier to microbial degradation in the rumen (Wang et al., 2007). Rice straw also has been investigated as a raw material for biofuel (El-Zawawy et al., 2011; Oberoi et al., 2012). Like other lignocellulosic biomasses, the process of ethanol production is difficult because rice straw consists of not only a simple sugar and starch but also a cellulose component. Enzymatic hydrolysis and fermentation and other multistep pretreatments are necessary to overcome the presence of lignin and the crystalline nature of cellulose. Further investigation is still required to achieve higher reaction rates and greater yields of each process in ethanol production.