Monday, May 4, 2009
5-46
Cellulase enzymes production from rice straw pretreated without sulfuric acid by Acremonium cellulolyticus
Akihiro Hideno1, Hiroyuki Inoue2, Kenichiro Tsukahara2, Xu Fang2, Takashi Endo2, and Shigeki Sawayama2. (1) Senior Research Fellow Center, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime, Japan, Matsuyama, Japan, (2) Biomass Technology Research Center, National Institute of Advanced Industrial Science and Technology, 2-2-2 Hiro-suehiro, Kure, Japan
Lignocellulosic biomass is an abundant renewable resource that can serve as a substrate for the production of alternative fuels, such as ethanol. Recently, rice straw which can be a potential source for ethanol production has been attracted a lot of interest in Asian countries. The digestibility of lignocellulosic biomass by enzymatic saccharification and the cost of cellulase enzymes are important factors for ethanol production. We have been studied the wet disk-milling pretreatment without sulfuric acid, and proposed that as an economical pretreatment for enzymatic hydrolysis of rice straw. In this study, we investigated the cellulase enzymes production using the pretreated rice straw as substrates to produce cellulase enzymes at a lower cost. The rice straw cut out to less than 3 mm by the cutter mill was pretreated by the wet disk milling, the ball milling and the hot compressed water treatment. These pretreated rice straw and Solka floc (80% crystalline cellulose) were used as carbon sources for cellulase enzymes production by the fungus Acremonium cellulolyticus. The enzyme activities in the supernatant of these cultures as crude enzyme preparations were measured. The FPase activities in ball milled and disk milled samples were as much high as that in Solka floc. On the other hand, the xylanase and xylosidase activities in ball milled and disk milled samples were higher than them in Solka floc. This work was supported by the Resional Biomass Energy Project, Ministry of Agriculture, Forestry and Fisheries, Japan