For example, straw has been used extensively as a raw material 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