碱液湿磨预处理对稻草材料性状及酶解的影响  

Effects of integrated wet-milling and alkali pretreatment on the properties and enzymatic hydrolysis of rice straw

作　　者：蒋学剑[1] 缪冶炼[1] 陈介余 徐子栋[1] 钱莉[1] 林丽军[1] 

机构地区：[1]南京工业大学食品与轻工学院,材料化学工程国家重点实验室,南京210009 [2]日本秋田县立大学生物资源学部,秋田010-0195

出　　处：《食品科技》2010年第11期190-195,共6页Food Science and Technology

基　　金：国家自然科学基金委-广东省政府联合基金(U0733001);国家重点基础研究发展计划(973项目,2009CB724700)

摘　　要：稻草资源丰富,但由于其成分和结构复杂,所含的纤维素、半纤维素难以被酶解成为可发酵性糖。论文采用碱液湿磨法在常温条件下对稻草进行预处理1 h,调查了预处理NaOH浓度对稻草的成分组成和结构、以及酶解中还原糖收率的影响,同时对稻草酶解反应进行动力学分析,求出了米氏方程的米氏常数Km和最大反应速率rmax。实验结果表明,采用1%NaOH溶液对稻草进行预处理后,木质素含量从12.4%降低至10.4%、纤维素结晶结构消失、可及度从639.6%增加至1044.6%。未处理稻草酶解中,还原糖收率为13.4%、Km为66.8 mg/mL、rmax为312.5μmol/(min.mL)。1%NaOH预处理稻草的还原糖收率为41.4%,Km为15.9 mg/mL,rmax为666.7μmol/(min.mL)。木质素去除、纤维素晶体结构消失、可及度改善是稻草酶解反应速率和还原糖收率提高的主要原因。Rice straw is a sort of biomass resource in abundance.However,it is difficult to convert the cellulose and hemicellulose contained in the rice straw into fermentable sugars because of its complex chemical composition and structure.An integrated wet-milling and alkali pretreatment was applied to the rice straw for 1 h.The effects of NaOH concentration in the pretreatment on chemical composition,structure and reducing-sugar yield of rice straw were investigated.The Michaelis constant（Km） and maximum reaction rate（rmax）of Michaelis-Menten equation were determined for the enzymatic reaction.It was shown that the lignin content was decreased from 12.4% to 10.4%;the crystalline structure was disrupted;and the water retention value（WRV） was increased from 639.6% to 1044.6% for rice straw by the pretreated with 1% NaOH.The reducing-sugar yield was 13.4%;the Km was 66.8 mg/mL;and the rmax was 312.5 μmol/（min.mL） in the enzymatic hydrolysis of untreated rice straw.The reducing-sugar yield was 41.4%;the Km was 15.9 mg/mL;and the rmax was 666.7 μmol/（min.mL） in the enzymatic hydrolysis of rice straw pretreated with 1% NaOH.The improvement of enzymatic reaction rate and reducing-sugar yield was resulted from the lignin removal,crystalline-structure disruption and accessibility increase in rice straw.

关 键 词：稻草 预处理 酶解 化学成分 动力学分析 

分 类 号：TQ353.425[化学工程]