Research progress in microbial degradation of straw lignin

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.

Key words:straw;lignin;microbial degradation;lignin-degrading enzymes;mechanism of bio-degradation