title: Efficient bioconversion of rice straw to ethanol with TiO2/UV pretreatment.
abstract: Rice straw is a lignocellulosic biomass that constitutes a renewable organic substance and alternative source of energy; however, its structure confounds the liberation of monosaccharides. Pretreating rice straw using a TiO(2)/UV system facilitated its hydrolysis with Accellerase 1000(™), suggesting that hydroxyl radicals (OH·) from the TiO(2)/UV system could degrade lignin and carbohydrates. TiO(2)/UV pretreatment was an essential step for conversion of hemicellulose to xylose; optimal conditions for this conversion were a TiO(2) concentration of 0.1% (w/v) and an irradiation time of 2 h with a UV-C lamp at 254 nm. After enzymatic hydrolysis, the sugar yields from rice straw pretreated with these parameters were 59.8 ± 0.7% of the theoretical for glucose (339 ± 13 mg/g rice straw) and 50.3 ± 2.8% for xylose (64 ± 3 mg/g rice straw). The fermentation of enzymatic hydrolysates containing 10.5 g glucose/L and 3.2 g xylose/L with Pichia stipitis produced 3.9 g ethanol/L with a corresponding yield of 0.39 g/g rice straw. The maximum possible ethanol conversion rate is 76.47%. TiO(2)/UV pretreatment can be performed at room temperature and atmospheric pressure and demonstrates potential in large-scale production of fermentable sugars.
authors: Research Institute for Catalysis, Chonnam National University, Gwangju, 500-757, Korea.
authors: Hee-Kyoung
authors: HK
authors: Kang
authors: Doman
authors: D
authors: Kim
mesh_terms: D001673:Biodegradation, Environmental; D000431:Ethanol / Q000138:chemical synthesis* / Q000528:radiation effects; D012275:Oryza / Q000737:chemistry* / Q000528:radiation effects*; D035261:Plant Components, Aerial / Q000737:chemistry* / Q000528:radiation effects; D010936:Plant Extracts / Q000737:chemistry* / Q000528:radiation effects; D011829:Radiation Dosage; D014025:Titanium / Q000737:chemistry* / Q000528:radiation effects*; D014466:Ultraviolet Rays
chemical_list: D010936:Plant Extracts; C009495:titanium dioxide; D000431:Ethanol; D014025:Titanium