Alkaline-peroxide Treatment for Enzymatic Hydrolysis of Japanese Cypress (Chamaecyparis obtusa)

Abstract

In Japan, softwood is one of the suitable materials for production of bio-fuels, since forest of softwood accounts approximately 90% in artificial forest in Japan, and it is widely used for constructing the traditional Japanese house. Japanese cypress (Chamaecyparis obtusa), which is known for its high quality lumber has been attracted a lot of interest as a potential feedstock in Japan. The conditions of alkaline peroxide pretreatment were investigated for the enzymatic hydrolysis of Japanese cypress in this study. The suitable condition of the pretreatment was as follows; at 70 °C with 2M sodium hydrate (NaOH) of and 6M hydrogen peroxide (H₂O₂). Almost of hemicellulose and approximately 60% of lignin were disappeared in the AP-pretreated sample. The AP-pretreated sample had the high-crystallinity and the celluolose nano fibers and nano scale "raising" on the surface. The suitable enzyme was Accellease1500 resulted in approximately 60%-glucose yield with 20 mg-protein/g-substrate. These results suggest that the alkaline peroxide hydrogen treatment has the potential as the pretreatment for obtaining glucose from softwood such as Japanese cypress in enzymatic hydrolysis.