Kato Hiroyuki, Miura Daisuke, Kato Masashi, Shimizu Motoyuki
Graduate School of Agriculture, Faculty of Agriculture, Meijo University, Nagoya, Aichi, 468-8502, Japan.
Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, 305-8566, Japan.
Appl Microbiol Biotechnol. 2024 Dec 11;108(1):532. doi: 10.1007/s00253-024-13371-4.
White-rot fungi, such as Phanerochaete chrysosporium, play a crucial role in biodegrading lignocellulosic biomass including cellulose, hemicellulose, and lignin. These fungi utilise various extracellular and intracellular enzymes, such as lignin peroxidases, manganese peroxidases, versatile peroxidases, monooxygenases, and dioxygenases, to degrade lignin and lignin-derived aromatics, thereby significantly contributing to the global carbon cycle with potential applications in industrial bioprocessing and bioremediation. Although the metabolism of lignin fragments in P. chrysosporium has been studied extensively, the enzymes involved in fragment conversion remain largely unknown. This review provides an overview of the current knowledge regarding the metabolic pathways of lignin and its fragments by white-rot fungi. Recent studies have elucidated the intricate metabolic pathways and regulatory mechanisms of lignin-derived aromatic degradation by focusing on flavoprotein monooxygenases, intradiol dioxygenases, homogentisate dioxygenase-like proteins, and cytochrome P450 monooxygenases. Metabolic regulation of these enzymes demonstrates the adaptability of white-rot fungi in degrading lignin and lignin-derived aromatics. The interplay between the central metabolic pathways, haem biosynthesis, and haem-dependent NAD(P)H regeneration highlights the complexity of lignin degradation in white-rot fungi. These insights improve our understanding of fungal metabolism and pave the way for future studies aimed at leveraging these fungi for sustainable biotechnological applications. KEY POINTS: • White-rot fungi use enzymes to degrade lignin, and play a role in the carbon cycle. • Oxygenases are key enzymes for converting lignin-derived aromatics. • White-rot fungi adapt to metabolic changes by controlling the TCA/glyoxylate bicycle.
白腐真菌，如黄孢原毛平革菌，在生物降解包括纤维素、半纤维素和木质素在内的木质纤维素生物质方面发挥着关键作用。这些真菌利用各种细胞外和细胞内酶，如木质素过氧化物酶、锰过氧化物酶、多功能过氧化物酶、单加氧酶和双加氧酶，来降解木质素和木质素衍生的芳烃，从而对全球碳循环做出重大贡献，并在工业生物加工和生物修复中具有潜在应用。尽管对黄孢原毛平革菌中木质素片段的代谢进行了广泛研究，但参与片段转化的酶仍 largely 未知。本综述概述了关于白腐真菌木质素及其片段代谢途径的当前知识。最近的研究通过关注黄素蛋白单加氧酶、间苯二酚双加氧酶、尿黑酸双加氧酶样蛋白和细胞色素 P450 单加氧酶，阐明了木质素衍生芳烃降解的复杂代谢途径和调控机制。这些酶的代谢调控证明了白腐真菌在降解木质素和木质素衍生芳烃方面的适应性。中心代谢途径、血红素生物合成和血红素依赖性 NAD(P)H 再生之间的相互作用突出了白腐真菌中木质素降解的复杂性。这些见解增进了我们对真菌代谢的理解，并为未来旨在利用这些真菌进行可持续生物技术应用的研究铺平了道路。关键点：• 白腐真菌利用酶降解木质素，并在碳循环中发挥作用。• 加氧酶是转化木质素衍生芳烃的关键酶。• 白腐真菌通过控制三羧酸循环/乙醛酸循环来适应代谢变化。
