为了寻求一种提高纤维素酶解速度和转化率的新方法,采用静置、摇床振荡和钢球振荡三种不同的酶解方式进行汽爆麦草酶解和吸附实验。结果表明,钢球振荡方式不但增加了汽爆麦草对纤维素酶的吸附量,而且明显提高了酶解速度和底物转化率。采用钢球振荡进行汽爆麦草酶解的最佳酶活性浓度为3.6×10-7 mol/(s•mL),最佳转速为150 r/min,最佳酶解时间为24 h,还原糖得率为0.43。用环境扫描电镜观察三种不同方式酶解后的汽爆麦草的形态,经分析发现,钢球振荡还有助于减少产物对酶的抑制和提高底物对纤维酶的吸附和解吸频率。
Abstract
A novel method of enzymatic hydrolysis by cellulase, characterized by
high conversion yields and hydrolysis rates, is described. Three methods of enzyme adsorption and hydrolysis of steam-treated straw are compared: ball mill shaker, plate shaker, and static state. It was found that the ball mill shaker afforded the maximum extent of adsorption of cellulase, conversion yield, and hydrolysis rate. The optimum enzyme activity, mill speed and reaction time were found to be 3.6×10-7 mol/s×ml, 150 r/min and 24 h, respectively, giving a maximum reducing sugar yield of 0.43. The morphological changes in the steam-treated straw were characterized by scanning electron microscopy. It is proposed that the use of the ball mill shaker both reduces the degree of inhibition of the enzyme by reaction products and increases the rate of adsorption and desorption of the enzyme on the substrate.
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脚注
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