摘要
利用不同预处理方法获得的玉米秸秆底物研究木质素脱除对纤维素酶吸附量及酶解效率的影响。相比于其他处理方法,2%(质量分数)Na OH处理的底物具有最高的木质素脱除率(85%),最高的底物可及性[4.7 mg·(g葡聚糖)-1]及酶解效率(18.9%)。通过对不同处理获得的底物进行Langmuir吸附等温曲线模拟,获得了最大吸附量(Wmax)与吸附平衡常数(K),且木质纤维素酶水解效率与纤维素酶吸附量具有很好的线性关系(R2>0.8),表明脱除木质素能很好地提高底物可及性与酶解效率。然而,提高Na OH浓度(3%,4%)进一步脱除木质素时,底物可及性与碳水化合物转化为单糖的效率反而明显下降。因此,适当脱除木质素而提高底物对纤维素酶的可及性将有助于获得更有效的酶水解效果。
Experiments were conducted for various pretreated substrates to investigate the impact of lignin content on cellulase adsorption and substrate digestibility. Compared with other treatments, 2%（mass） Na OH pretreated solids with the highest level of lignin removal（85%） exhibited the highest accessibility to cellulase [4.7 mg protein·（g glucan）-1] and enzymatic digestibility（18.9%）. The obtained maximum adsorption capacity（Wmax） and equilibrium constant（K） derived from fitting the Langmuir adsorption isotherm for different delignified substrates indicated that the removal of lignin benefited cellulase adsorption. The relationship between cellulase adsorption capacities and enzymatic digestibility for raw and pretreated solids correlated well（R^2〉0.8）, supporting the hypothesis that carbohydrate conversion was primarily dominated by enhancing substrate accessibility owing to lignin removal. Nevertheless, further delignification by Na OH with concentrations of 3%（mass） and 4%（mass） was unfavorable to improving substrate accessibility to cellulase and enhancing carbohydrates conversion to monosaccharide. It appeared that the appropriate delignification to some degree was a significant pretreatment factor to be taken into consideration to achieve more effectively enzymatic digestibility.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2016年第5期2084-2092,共9页
CIESC Journal
基金
国家自然科学基金重点项目(31230057)
国家自然科学基金项目(31371787)
十二五科技部国家重点科技研究与发展规划项目(2012BAD34B07)~~
