环境微生物介导的木质素代谢及其资源化利用研究进展

木质素是一种丰富的芳烃生物大分子聚合物,其分解代谢与地球元素循环和生物资源利用密切相关。但由于木质素结构的复杂性和无规则性导致其难以降解,使得木质素降解的研究成为全球碳循环和生物质资源利用研究的难点。近年来,来自不同环境的微生物陆续被发现具有木质素降解能力,并解析出参与木质素分解代谢的多种氧化还原酶。然而对木质素详细的代谢过程仍不十分清楚,因此,探究木质素降解酶系、作用机理和代谢网络是研究微生物代谢木质素机理的关键。本文综述环境中参与木质素降解的微生物,重点解析其木质素解聚酶系组成、分泌机制和木质素的代谢途径,并在此基础上阐明近年来木质素生物转化的最新研究进展,以期为今后环境微生物代谢木质素机理及其资源化利用的研究提供参考。

Environmental microorganisms driven lignin biodegradation and their roles in lignin utilization

Lignin is a highly cross-linked aromatic heteropolymer. As it is one of the most abundant carbon reservoirs in the environment, its decomposition plays a key role in the global carbon cycle and biomass utilization. However, lignin degradation remains highly challenge, due to its inherent heterogeneity and recalcitrant chemical structure. Microorganisms from different environments have been found to have the capacities of lignin degradation. Moreover, a variety of oxidoreductases in these microorganisms have been identified to be involved in lignin degradation. However, the lignin degradation mechanisms are not yet well-studied. Thus, exploring the lignin-degrading enzyme system and metabolic network are critical to studying the mechanism of microbial metabolism of lignin. This article reviews the ligninolytic enzymes, including their components and extracellular secretion mechanism, as well as the lignin biodegradation pathways. Moreover, it provides clues to further explore mechanisms of lignin biodegradation and strategies of sustainable biomass utilization.