State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, Shandong, PR China.
State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, Shandong, PR China; Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, Shandong, PR China.
Bioresour Technol. 2018 Oct;266:19-25. doi: 10.1016/j.biortech.2018.06.050. Epub 2018 Jun 19.
Commercial cellulase preparations for lignocellulose bioconversion are mainly produced by the fungus Trichoderma reesei. The maximum cellulose conversion of T. reesei cellulase mixture was 15%-20% higher than that of Penicillium oxalicum in the hydrolysis of corncob residue and Avicel. Nevertheless, both preparations hydrolyzed more than 92% of cellulose in NaOH-mercerized Avicel. When added to Avicel hydrolysis residue that was less reactive to P. oxalicum cellulases, cellobiohydrolase I (CBH I) from T. reesei resulted in a higher cellulose conversion than its homologous proteins from P. oxalicum and Aspergillus niger at the same protein loadings. Further domain exchange experiment attributed the high hydrolytic efficiency of T. reesei CBH I to its inter-domain linker and cellulose-binding domain. The results in part explained the superior performance of T. reesei cellulases on the degradation of native crystalline cellulose, and highlighted the important role of cellulose-binding region in determining the degree of hydrolysis by cellulases.
用于木质纤维素生物转化的商业纤维素酶制剂主要由真菌里氏木霉（Trichoderma reesei）生产。里氏木霉纤维素酶混合物对玉米芯残渣和 Avicel 的水解的最大纤维素转化率比草酸青霉（Penicillium oxalicum）高 15%-20%。然而，这两种酶制剂在 NaOH-润胀的 Avicel 中水解超过 92%的纤维素。当添加到对草酸青霉纤维素酶反应性较低的 Avicel 水解残渣中时，来自里氏木霉的纤维二糖水解酶 I（CBH I）在相同的蛋白负载下比其来自草酸青霉和黑曲霉的同源蛋白具有更高的纤维素转化率。进一步的结构域交换实验将里氏木霉 CBH I 的高效水解效率归因于其结构域内连接子和纤维素结合结构域。研究结果部分解释了里氏木霉纤维素酶在降解天然结晶纤维素方面的优异性能，并强调了纤维素结合区域在决定纤维素酶水解程度方面的重要作用。
