Abstract: In the present paper bamboo was hydrothermally treated to overcome biomass recalcitrance for enzymatic hydrolysis.The effects of pretreatment temperature,residence time,adding amount of cellulase and bamboo kinds on enzymatic hydrolysis of glucan/xylan were investigated.The result shows that hydrothermal treatment can significantly improve total monosaccharide yield.The optimal pretreatment temperature is 190℃ and residence time 10 min.Approximately 74.3% glucan and 54.0% xylan were transformed after 72 h enzymatic hydrolysis using 15 FPU·(g glucan)^-1 of cellulose (about 1% of glucan),which are 3.5-fold and 4.7-fold of untreated substrate respectively.Too high treating temperature and too long staying time can lead to degradation of xylose and glucose,so total yield of monosaccharide decreases.If cellulase amount adding increases from 15 FPU·(g glucan)^-1 to 60 FPU·(g glucan)^-1,the total sugar recovery goes up 21.5% and 9.9% for treated and untreated bamboo,respectively. To rise enzymatic digestibility of bamboo,it was more effective using hydrothermal pretreatment than increasing enzyme amount.Hydrothermal pretreatment was sensitive to raw biomass materials and significantly different results were obtained for different bamboo materials.

Key words: hydrothermal pretreatment, bamboo, biomass, enzymatic hydrolysis, cellulose, ethanol

摘要： 采用间歇式水热预处理装置,研究了水热预处理用于竹子的酶解规律,探讨了不同温度、处理时间、纤维素酶添加量及原料种类对促进竹子酶解的效果及其影响。结果表明水热预处理能显著提升竹子的酶解率,在优化条件190℃、10 min水热预处理,添加15 FPU·(g葡聚糖)^-1纤维素酶,72 h葡聚糖与木聚糖酶解率分别为74.3%、54.0%,提高到原来的3.5倍和4.7倍。过高的预处理温度与过长的预处理时间都将导致木糖大量降解和部分葡萄糖降解,使单糖总量下降。纤维素酶的添加量从15 FPU·(g 葡聚糖)^-1提高到60 FPU·(g 葡聚糖)^-1,可使未作预处理和水热预处理竹子的总糖回收率分别提高21.5%和9.9%,其促进酶解的作用远低于预处理的效果,通过预处理增大酶的可及性是提高酶解率的关键。水热预处理对于生物质原料具有选择性,不同的竹子原料具有显著不同的效果。

关键词: 水热预处理, 竹子, 生物质, 酶解, 纤维素, 乙醇