Zhao Lei, Huang Ailan, Yang Mei, Zhang Minglu, Yu Fei, Lu Fuping, Chen Xiaohong, Wang Yanfei, Liu Fufeng
Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education; Tianjin Key Laboratory of Industrial Microbiology; College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, P. R. China.
Tianjin Key Laboratory of Marine Resources and Chemistry, College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, Tianjin 300457, P. R. China.
J Agric Food Chem. 2025 Jul 23;73(29):18390-18401. doi: 10.1021/acs.jafc.5c04782. Epub 2025 Jul 11.
Laccase from is widely used to improve lignin depolymerization. However, wild-type laccase usually lacks heat resistance, and its catalytic process is usually accompanied by the repolymerization of lignin, limiting its application. Herein, we performed site-saturation mutation on laccase, generating mutants A347H and N368L with activities increased by 2.37-fold and 2.46-fold, respectively. These mutants remain active at both 80 and 90 °C after 2 h. The above properties allowed them to efficiently catalyze native lignin depolymerization without mediators. Then, adding lytic polysaccharide monooxygenase (LPMO) and ascorbic acid further improved alkali lignin depolymerization, achieving a 40.87% depolymerization ratio. The insight into the product structure and reaction process suggested that the enhanced alkali lignin depolymerization was achieved by enhancing the cleavage of β--4 bond and C-C bond, as well as inhibiting lignin repolymerization. This laccase-LPMO coupling system presents a new strategy for high-efficiency processing of lignin.
来自[具体来源未提及]的漆酶被广泛用于促进木质素解聚。然而，野生型漆酶通常缺乏耐热性，并且其催化过程通常伴随着木质素的再聚合，限制了其应用。在此，我们对[具体来源未提及]漆酶进行了位点饱和突变，产生了突变体A347H和N368L，其活性分别提高了2.37倍和2.46倍。这些突变体在80℃和90℃下处理2小时后仍保持活性。上述特性使它们能够在无介体的情况下高效催化天然木质素解聚。然后，添加裂解多糖单加氧酶（LPMO）和抗坏血酸进一步提高了碱木质素解聚率，达到了40.87%。对产物结构和反应过程的深入研究表明，碱木质素解聚的增强是通过增强β-4键和C-C键的断裂以及抑制木质素再聚合来实现的。这种漆酶-LPMO耦合系统为木质素的高效加工提供了一种新策略。
