Proteomics Analysis Of Lignin Degradation Mechanism Of Lignin-Degrading Fungal Aspergillus Fumigatus G-13

Lignocellulose,because of its rich source,quantity,low price and other advantages to solve the current human resources shortage,environmental pollution and other issues of great significance,but the natural structure of wood quality has greatly hindered its use of resources and harmless treatment,The study and elaboration of lignin degradation mechanism can help to break through the bottleneck of the current lignin research and promote the industrialization process of lignin degradation and utilization.In this study,we premeditated the enzyme-producing regularity of 3 lignin monomer model compounds of Aspergillus fumigatus G-13 fermentation by controlling the addition of cellulose substrate and auxiliary carbon source?glucose?and culture conditions,To select a group of the most active expression of enzymes to analyze the proteomics and obtain the composition and classification of the enzymes in the lignin model compound.The results showed that the largest group was the fermentation substrate with coumarin acid and microcrystalline cellulose respectively,and the fermentation substrate was fermented by static fermentation with mustard acid,carboxymethyl cellulose and glucose.The proteomic analysis of model compounds showed that 2,103 proteins were reduced,1759 proteins were raised,and 3,862 protein points were significantly changed.Through cluster analysis of differential proteins,go enrichment analysis and pathway enrichment analysis,the differential proteins related to lignin degradation were mainly enriched by enzymes-related proteins,fiber-glucose/quinone reductase and aromatic ring-cracking enzymes and ferulic acid esterase-related proteins.In the substrate for mustard acid,carboxymethyl cellulose and glucose using liquid shaker fermentation conditions,strain a.Fumigatus G-13 uses the above 3 enzymes to obtain higher lignin degradation efficiency by using the carboxylic acid ester bond,the ether bond and the ester bond between the lignin structural units and the end of the electron transfer chain.And overall,strain A.fumigatus G-13 degradation lignin monomer model compounds are mainly enriched by carbon source and energy,glycerol metabolism,nucleotide metabolism,and the related pathway of monoamine metabolism.Under this condition,the change of cellulose model compounds and the addition of glucose enhance the energy metabolism of the somatic cells,the growth and reproduction of the bacteria and the degradation of lignin.Secondly,after crushing the acacia and walnut shells over 60-80 mesh,48h was pretreated by 8%Ca?OH?₂ in 60?,and a 1:1.5?volume?culture system of solid-liquid ratio was selected to treat 18d samples using Itraq technique for proteomic analysis without 8%Ca?OH?₂ pretreatment samples were used as controls.The results showed that both the Sophora and walnut shells before and after chemical treatment showed a large number of differential protein increases.Through cluster analysis of differential proteins,go enrichment analysis and pathway enrichment analysis,it is known that the main classification of proteins related to lignin degradation is similar to that of A.fumigatus G-13 fermentation with lignin model compound as substrate,but the ferulic acid degrading enzyme does not show significant difference.And overall,strain A.fumigatus G-13degradation of natural lignin substrate difference proteins are mainly enriched in carbon source and energy,nucleotide metabolism related pathways.Under the condition of pretreatment,the enzyme activity of the walnut shell was more significant than that of Sophora japonica,that is,the pretreatment would improve the lignin surface structure and chemical bond of walnut shell,and induce the degradation of protein by the lignin,but the difference protein content and lignin enzyme activity were smaller than that of Sophora japonica.To sum up,in the process of degradation of lignin by A.fumigatus G-13,ferulic acid esterase was a key factor in the degradation of lignin,and the different proteins were mainly concentrated in the pathways of carbon source and energy and nucleotide metabolism.