木质素生物降解的脱甲基机制研究进展

Research progress in the demethylation mechanism of ligninbiodegradation

木质素是由苯丙烷结构单元通过多种化学键交联组成的复杂芳香族高聚物。由于其结构的复杂性和异质性,使得木质素的高效降解与经济转化成为了一个世界性的难题。近年来,科学研究发现微生物特有的非特异性氧化还原体系及芳香族化合物多元代谢降解能力,为解决木质素的资源化利用提供了新的思路和方向。由于大部分木质素衍生的芳香族单体在苯环不同位置上都含有甲氧基,使得脱甲基化成为了木质素衍生芳香族化合物代谢的关键限速步骤。本综述就近年来在木质素生物降解过程中的脱甲基生物学和酶学机制研究进行了较为全面的总结,并以利用芳香族脱甲基酶进行木质素高值转化方面的典型研究案例进行分析,阐明了微生物脱甲基过程机制解析以及新型脱甲基酶的挖掘对于木质素降解与转化的重要意义。

Lignin is a heterogeneous aromatic biopolymer composed of diverse aromatic monomers linked by various types of chemical bonds,which make the efficient degradation and cost-effective transformation of lignin a formidable global issue.Recent studies have discover unique non-specific redox systems inherent in microorganisms and the metabolic capacity of microorganisms for degrading aromatic compounds,shedding light on lignin valorization.Given that most of lignin-derived aromatic monomers contain methoxy groups,demethylation emerges as a rate-limiting step in the metabolism of these compounds.This review offers an extensive summary of the latest studies about the biological and enzymatic mechanisms of demethylation during the biodegradation of lignin.Meanwhile,by examining exemplary studies on lignin valorization with novel aromatic demethylases,this paper highlights the pivotal role of understanding microbial demethylation mechanisms and mining new demethylases in lignin degradation and transformation.