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.
Appl Biochem Biotechnol. 2010 Oct;162(4):1195-205. doi: 10.1007/s12010-009-8892-5. Epub 2010 Jan 12.
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.
甘蔗渣半纤维素在碱性介质中用过氧化氢进行一步化学提取得到分离。该多糖含有 80.9%的木糖和少量的 L-阿拉伯糖、4-O-甲基-D-葡萄糖醛酸和葡萄糖，用嗜热曲霉（Thermoascus aurantiacus）的粗酶提取物在 50°C 下水解。通过底物浓度在 0.5-3.5%（w/v）范围内、酶用量为底物的 40-80 U/g 和反应时间为 3-96 h 的条件下，应用 2(2) 因子设计，研究了导致木糖和低聚木糖（DP 2-5）最佳产率的酶解条件。用 2.6%的底物和 60 U/g 的木聚糖酶用量，可获得最大的低聚木糖转化率（37.1%）。多项式模型预测的木二糖最大产率为 41.6%。从甘蔗渣半纤维素中提取的粗酶提取物中，嗜热曲霉生成了 39%的木糖、59%的木二糖和 2%的其他低聚木糖。
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