Exploration Of High-efficiency Lignocellulose Degrading Enzyme From Wheat Pathogens

Biomass energy is an important branch of renewable energy.Compared with petroleum and other fossil fuels,agricultural and forestry biomass resources have the characteristics of renewability and sustainability,and are rich in resources.Its development and utilization are of great significance to alleviate energy crisis and greenhouse gas emissions and other energy and environmental problems.Straw and waste wood produced in agricultural and forestry production process can be collectively referred to as agroforestry lignocellulose,which occupies an important proportion in biomass feedstock.However,compared with petrochemical products,the cost of using lignocellulose to produce biofuels and bio-based products is still too high.The technology in key point is enzymatic hydrolysis of lignocellulose polysaccharides to produce fermentable monosaccharides.The ways to reduce the cost of enzymatic hydrolysis include reducing the cost of cellulase production and improving the enzymatic hydrolysis efficiency of lignocellulose.The complexity and diversity of lignocellulose are important factors which lack enzymatic hydrolysis efficiency of lignocellulose.Lignocellulose or plant cell walls are mainly composed of cellulose,hemicellulose and lignin.The cell walls of different crops show diversity in composition and structure,which limits the effective conversion and utilization of lignocellulose substrates.Recent studies have shown that plant pathogens own specific high degradation efficiency for their host plant cell wall substrates.Functional genomics analysis further showed that plant pathogenscontained various kinds and quantities of glycoside hydrolases(GH,EC3.2.1)compared with non-pathogens or saprophytic bacteria,which were used to synergistically degrade different polysaccharide components in plant cell walls.Based on our previous studies,we made further analysis and comparison of the synergistic effects in enzymatic hydrolysis of lignocellulose among extracellular enzymes of Fusarium graminearum,Bipolaris sorokiniana,Neurospora crassa and Trichoderma reesei.It was found that the mixed enzymes of pathogens and non-pathogens had higher synergistic activity for lignocellulose hydrolysis than those of non-pathogens or pathogens.Ion chromatography and Fourier transform infrared spectroscopy analysis towards lignocellulose substrates after enzymatic hydrolysis further showed that the way of enzymatic hydrolysis of lignocellulose substrates by pathogens and non-pathogens might be different,resulting in enhanced synergistic effect of lignocellulose degradation by mixed enzymes.We further added various types of prokaryotic expressed cellulases origin from Neurospora crassato the fermentation broth of wheat pathogenic which caused enhancement in the synergistic activity of enzymatic hydrolysis towards lignocellulose by wheat pathogens.It is suggested that the synergistically enhancement effect between pathogenic and non-pathogenic enzymes is related to the composition of their enzymes.On this basis,further analysis aremade to compare the transcriptional levels of GH family genes in pathogens and non-pathogens under different substrate inductional conditions,in order to explore potential synergistic enzymes.In summary,there is a significant synergistic enhancement effect of lignocellulose enzymatic hydrolysis between wheat pathogens and saprophytic fungi.This synergistic enhancement effect is related to different composition of lignocellulose degrading enzymesbetween wheat pathogens and saprophytic fungi.Understanding their synergistic enhancement effect will help to tap and utilize the abundant lignocellulose degrading enzymes resources in plant pathogens which will make further efforts to the enzymatic transformation and utilization efficiency of high agricultural and forestry biomass resources.