title: Xylooligosaccharides production from alkali-pretreated sugarcane bagasse using xylanases from Thermoascus aurantiacus.
abstract: Sugarcane bagasse hemicellulose was isolated in a one-step chemical extraction using hydrogen peroxide in alkaline media. The polysaccharide containing 80.9% xylose and small amounts of L-arabinose, 4-O-methyl-D-glucuronic acid and glucose, was hydrolyzed by crude enzymatic extracts from Thermoascus aurantiacus at 50 degrees C. Conditions of enzymatic hydrolysis leading to the best yields of xylose and xylooligosaccharides (DP 2-5) were investigated using substrate concentration in the range 0.5-3.5% (w/v), enzyme load 40-80 U/g of the substrate, and reaction time from 3 to 96 h, applying a 2(2) factorial design. The maximum conversion to xylooligosaccharides (37.1%) was obtained with 2.6% of substrate and xylanase load of 60 U/g. The predicted maximum yield of xylobiose by a polynomial model was 41.6%. Crude enzymatic extract of T. aurantiacus generate from sugarcane bagasse hemicellulose 39% of xylose, 59% of xylobiose, and 2% of other xylooligosaccharides.
authors.affiliation: Department of Biotechnology, School of Engineering of Lorena, University of São Paulo-USP Estrada Municipal do Campinho, s/n degrees -CP 116, 12602-810 Lorena SP, Brazil.
authors.forename: Michel
authors.initials: M
authors.lastname: Brienzo
authors.forename: Walter
authors.initials: W
authors.lastname: Carvalho
authors.forename: Adriane M F
authors.initials: AM
authors.lastname: Milagres
mesh_terms: D000468:Alkalies / Q000737:chemistry; D002482:Cellulose / Q000737:chemistry*; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D006868:Hydrolysis; D007700:Kinetics; D011134:Polysaccharides / Q000378:metabolism*; D031786:Saccharum / Q000737:chemistry*; D055327:Thermoascus / Q000201:enzymology*; D014994:Xylose / Q000378:metabolism*
chemical_list: D000468:Alkalies; D005656:Fungal Proteins; D011134:Polysaccharides; D002482:Cellulose; C027433:bagasse; D014994:Xylose; D043364:Endo-1,4-beta Xylanases