Abstract

The inhibitory effect of xylan on enzymatic hydrolysis of cellulose with different ultrastructure is not clear. In this work, cellulose II, cellulose III, and amorphous cellulose were prepared from cellulose I by NaOH, ethylenediamine, and ball-milling treatment, respectively. Their crystalline structure and enzymatic hydrolyzability were systematically characterized and compared with cellulose I. Furthermore, the inhibitory effect of xylan on cellulose with different ultrastructure was investigated in detail. Results suggested that the enzymatic hydrolyzability of different cellulose increased in sequence from cellulose I (25.4%), cellulose III (41.7%), cellulose II (56.2%) to amorphous cellulose (77.4%) at enzyme loadings of 5.56 mg protein/g substrate. The enzymatic hydrolyzability of allomorphic cellulose was strongly inhibited by xylan, while a little inhibition was observed for amorphous cellulose. It was found that cellobiose released from different cellulose was decreased after the addition of xylan. At the initial hydrolysis stage, the inhibition degree was obviously increased for all of different cellulose, and then, the inhibition degree of cellulose I and cellulose II gradually decreased as enzymatic hydrolysis proceeded, while the inhibition degree of cellulose III and amorphous cellulose had changed a little. In addition, at a longer time of hydrolysis, the inhibition degree was decreased with the increase of cellulase dosage except for cellulose III, which remained approximately unchanged. Overall, this study demonstrated that the inhibitory effect of xylan on cellulose hydrolysis was substantially affected by the ultrastructure of cellulose, and thus it provides new insights for relieving the inhibitory effect of xylan by altering the ultrastructure of cellulose.

Graphical abstract

中文翻译：

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木聚糖对纤维素酶促水解的抑制作用取决于纤维素的超微结构

摘要

木聚糖对具有不同超微结构的纤维素的酶促水解的抑制作用尚不清楚。在这项工作中，分别通过NaOH，乙二胺和球磨处理从纤维素I制备纤维素II，纤维素III和无定形纤维素。系统地表征了它们的晶体结构和酶水解性，并与纤维素I进行了比较。此外，详细研究了木聚糖对具有不同超微结构的纤维素的抑制作用。结果表明，在5.56 mg蛋白质/ g底物的酶载量下，不同纤维素的酶促水解能力从纤维素I（25.4％），纤维素III（41.7％），纤维素II（56.2％）到无定形纤维素（77.4％）依次增加。 。木聚糖强烈抑制同种异形纤维素的酶水解性，同时观察到对无定形纤维素的抑制作用很小。发现在添加木聚糖后，从不同纤维素释放的纤维二糖减少了。在初始水解阶段，所有不同纤维素的抑制度均明显增加，然后，随着酶水解的进行，纤维素I和纤维素II的抑制度逐渐降低，而纤维素III和无定形纤维素的抑制度发生了变化。小。另外，在更长的水解时间，抑制程度随着纤维素酶剂量的增加而降低，除了纤维素III以外，纤维素III几乎保持不变。总体而言，这项研究表明木聚糖对纤维素水解的抑制作用受纤维素超微结构的影响很大，

图形概要