title: Production and characterization of cellulases and hemicellulases by Acremonium cellulolyticus using rice straw subjected to various pretreatments as the carbon source.
abstract: Cellulases and hemicellulases are key enzymes in the production of alternative fuels and chemicals from lignocellulosic biomass-an abundant renewable resource. Carbon source selection is an important factor in the production of cellulases and hemicellulases. Rice straw--a potential ethanol source--has recently gained considerable interest in Asian countries. Here, we investigated the production of cellulases by using rice straw subjected to various pretreatments as substrates in order to produce cellulases at low costs; we also identified the enzymes' characteristics. Rice straw cutter milled to <3mm was pretreated by wet disk milling, dry ball milling, or hot-compressed water treatment (HCWT). Pretreated rice straw and commercial cellulose, Solka Floc (SF), were used as carbon sources for cellulase production by the fungus Acremonium cellulolyticus. Filter paper cellulase, β-xylanase, and β-xylosidase production from ball- and disk-milled samples were higher than those from SF. Enzymatic activity was absent in cultures where HCWT rice straw was used as carbon source. Wet disk-milled rice straw cultures were more suitable for enzymatic hydrolysis of pretreated rice straw than SF cultures. Thus, wet disk milling may be a suitable pretreatment for producing substrates for enzymatic hydrolysis and generating inexpensive carbon sources for cellulase production.
authors: Biomass Technology Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima 737-0046, Japan.
authors: Akihiro
authors: A
authors: Hideno
authors: Hiroyuki
authors: H
authors: Inoue
authors: Kenichiro
authors: K
authors: Tsukahara
authors: Shinichi
authors: S
authors: Yano
authors: Xu
authors: X
authors: Fang
authors: Takashi
authors: T
authors: Endo
authors: Shigeki
authors: S
authors: Sawayama
mesh_terms: D000164:Acremonium / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism; D018533:Biomass; D001709:Biotechnology / Q000379:methods; D044602:Cellulases / Q000096:biosynthesis*; D002482:Cellulose / Q000378:metabolism; D003470:Culture Media; D000431:Ethanol / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000096:biosynthesis*; D006868:Hydrolysis; D008031:Lignin; D012275:Oryza / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D003470:Culture Media; C036909:lignocellulose; D000431:Ethanol; D002482:Cellulose; D008031:Lignin; D044602:Cellulases; D006026:Glycoside Hydrolases; C023305:hemicellulase