微生物降解秸秆木质素的研究进展

Research progress in microbial degradation of straw lignin

摘要:

我国秸秆资源丰富，每年产生逾8亿t作物秸秆。通过秸秆直接还田或肥料化还田不仅可以减少化肥的施用量，缓解农业污染压力，还能实现农作物秸秆的循环利用。木质素结构复杂，且与纤维素和半纤维素相互缠绕，因此秸秆的自然腐解过程中，木质素是主要的限速因子，为了提高降解效率，木质素降解菌的发掘和降解机制也逐渐成为研究热点。本文综述了降解木质素的真菌和细菌的研究现状，对比其真菌和细菌降解特性的优缺点并分析复合降解菌群的优势。随后对木质素降解酶系的酶学性质、在不同微生物中的表达特性进行总结，对木质素降解机制及衍生芳烃代谢路径的研究进展进行综述。最后整理木质素降解微生物在秸秆肥料化技术中的应用进展，并探讨了微生物降解秸秆木质素的应用前景和未来的研究方向。

Abstract:

China has abundant straw resources, with over 800 million tons of crop straw produced annually. Directly returning straw to farmlands or using it as fertilizer can not only reduce the use of chemical fertilizers and alleviate agricultural non-point source pollution but also achieve the recycling of crop straw. Lignin has a complex structure and is entangled with cellulose and hemicellulose. Therefore, in the natural decomposition process of straw, lignin is the main limiting factor. Mining lignin-degrading microorganisms and deciphering their degradation mechanisms to improve the degradation efficiency have gradually become research hotspots. By reviewing the available studies of lignin-degrading microorganisms, we compared the lignin degradation characteristics of fungi and bacteria and analyzed the advantages of composite degrading consortia. Subsequently, we summarized the properties of lignin-degrading enzymes and their expression characteristics in different microorganisms, and introduced the research progress in lignin degradation mechanisms and derived aromatic hydrocarbon metabolic pathways. Finally, we reviewed the application of lignin-degrading microorganisms in the production of straw fertilizers and put forward the application prospects and research directions of microbial degradation of lignin in straw.