Study On The Mechanism Of Cell Wall Cellulose Digestibility Of Corn Stover

Corn has the advantages of high biomass yield and strong adaptability to environment.Meanwhile,corn stalk is an ideal raw material for lignocellulosic bioenergy production,but the complex chemical composition and dense physical structure of its cell wall limit the contact of enzymes.Meanwhile,the highly ordered crystalline structure of cell wall cellulose has hydrophobicity,which makes the enzymatic hydrolysis and conversion utilization more difficult.This study combined with physics,chemistry and microscopic observation research methods,such as multilevel and multi-angle analysis of the 12 different varieties of maize straw and place on its physical structure and chemical composition,to explore the core of restriction enzyme solution function mechanism,in order to offer a theoretical basis for the maize straw cellulose ethanol production and technical support.The main results are as follows:1.Determine the chemical components of the whole plant and different parts.Correlation analysis showed that there were significant differences in cellulose content among different parts,and hemicellulose content and cellulose content had the same trend.There was a negative correlation between lignin content and cellulose content,but no correlation between neutral detergent content and ash content and cellulose content.2.The determination of sugar production by enzymatic hydrolysis showed that the conversion rate of different parts of corn stalk was significantly different.The degree of enzymatic hydrolysis in pith and leaf was much higher than that in stem and leaf sheath.3.Combined with the analysis methods of crystallinity,microcrystalline size,degree of polymerization,porosity,cell wall thickness,cell type distribution and pore size distribution,the factors affecting enzymatic hydrolysis were explained.Correlation analysis showed that the ratio of large pores to small pores was the key positive factor limiting the enzymatic conversion of straw materials.4.The differences in the physical and chemical structures of cell walls affect cellulase’s adsorption of substrates.It can be concluded that the porosity of cell wall and the effective adsorption of cellulase on substrates are the core factors limiting the enzymatic hydrolysis and conversion of corn stalks,and also the key to the production of cellulosic ethanol from corn stalks.