Expression And Characterization Of A Polysaccharide Monooxygenase From Arthrobotrys Sp.

Lignocellulose is one of the most abundant renewable resources in the earth.The efficient bioconversion of lignocellulosic feedstock to biofuels has wide application prospect and huge economic value.However,the major components of lignocellulosic biomass: lignin,hemicellulose and cellulose formed complex construction via non-covalent bonds and covalent cross-linkages,which decelerates the degration of biomass and hinders its industrialized application.Nowadays,enzymatic degradation of lignocellulose is often considered as the most promising approach for the future.However,the largest obstacle to economical production of cellulosic biofuels by enzymatic degradation is cost-effectively releasing sugars from recalcitrant lignocellulose.Therefore,domestic and foreign scholars are committed to the development and transformation of high efficiency cellulose degradation enzymes.In this work,we chose a lytic polysaccharide monooxygenases(LPMO)gene with high homology with other sources of LPMO from Arthrobotrys sp.strain CX1.by comparing the results of genomic data and differential transcriptome sequencing.The LPMO gene was obtained by using reverse transcription PCR(RT-PCR),and it was named lpmo-10331.The gene of LPMO from CX1 contained an open reading frame consisting of 1020 bp and coding for 340 amino acid residues.The mature LPMO could be expressed functionally in Pichia pastoris X-33 with pPICZ?A vector.The recombinant enzyme LPMO10331 was characterized by scanning electron microscopy(SEM),X-ray diffraction(XRD),and ion chromatography techniques.The oxidation-reduction reaction of the enzyme and the Whatman No.1 filter paper in the presence of 1 mM vitaminC was found to destroy the crystalline region of cellulose,producing a cellulose oligosaccharide and reducing the crystallinity of cellulose(CrI).The results of our work not only increase the understanding of LPMO,but also provide a new reference for further research and application of LPMOs.