31 × 1014 of dry matter per year) of renewable biomass in the world [12]. Therefore, RS is considered a powerful biomass for the production of monomeric sugars. However, RS is difficult to depolymerize using only hydrolases owing to its polymeric outer cell-wall membrane, which is surrounded by amorphous compounds (especially lignins). To commercialize the production of cellulosic bioethanol, the effective conversion of recalcitrant biomass, especially lignocellulose,

into fermentable monomers appears to be necessary [1], [18] and [8]. Irradiation technology (especially electron beam find more irradiation) has been widely used for changing the properties of polymers [7]. Such technology also extends the range of applications for the irradiated material. The main role of the irradiation program is to focus on the radiation-induced changes in the microstructural crystallinity of the substrates. Irradiation induces a chain–cleavage

mechanism by depolymerizing the polymeric material. Recently, an environmentally friendly electron beam irradiation (EBI) pre-treatment, which produces less inhibitory byproducts than the conventional thermochemical methods, was developed using a linear electron accelerator, and was subsequently evaluated with various analytical methods [2]. Based on the mass balance of lignocellulolysis, the commercial value of the irradiation program is quite high due to the instantaneous processing. Furthermore, this program Cobimetinib purchase does not need a temperature control (e.g., a cooling process) or a neutralization step owing to the presence of stable Pregnenolone downstream products and the absence of any byproducts. However, the exclusive use of EBI to enhance the enzymatic hydrolysis of lignocellulose has not been commercially successful. Therefore, to address the disadvantages in the original EBI system, such as, low sugar yields, a water-soaked RS was used as part of the advanced system. I conducted this study to determine the feasibility and efficiency of the water soaking-based electron beam

irradiation. Its impact was evaluated from the indices that measured the enzymatic hydrolysis and fermentation efficiencies. Based on the condition (1 MeV and 80 kGy at 0.12 mA) for a systemized procedure [2], rice straw (RS) was irradiated with accelerated electrons by using a linear electron accelerator (Korea Atomic Energy Research Institute, Daejeon, Korea). Prior to the irradiation, RS was soaked in mineral water overnight in order to enhance the effects of the substrate pretreatment. The moisture contents (based on solid:liquid ratios) used were approximately 0% (0; control), 52% (2), 68% (1), 81% (0.5; saturation point), and over 81% (0.25 or 0.125; colloidal suspension), respectively.