Cloning Of Glucanase Gene From Chaetomium Cupreum And Its Expression In Pichia Pastoris

China is a vast agricultural country, and has a very big pesticide consumption,most of which is chemical pesticides. Long application of chemical pesticides cancause many environmental and food safety issues, such as induced resistance, dosedependent manner, low specificity which may destroy the ecosystem structure, andso on. With the increase of the environmental protection consciousness of people,biological pesticides provide a effective and environmental protective solution tosolve those problems.With the ability of biological control, Chaetomium spp can be used formicrobial pesticides. This fungi can generate two enzyme include chitinase andglucanase which can degrade the cell wall of plant pathogenic fungi, and inhibit thegrowth of plant pathogenic fungi effectively with other mechanisms. Chaetomiumcupreum is one of them.This study is designed to search for a glucanase gene from Chaetomiumcupreum and test its ability to prevent plant pathogenic fungi.A glucanase gene named cgc is found from the genome of Chaetomiumcupreum. This gene is1709bp, and includes one intron from83bp to267bp and twoextrons. Bioinformatics analysis shows that this gene can encode541amino acidresidues, of which the former19amino acid is the signal peptide sequence, and itstheoretical molecular weight is about55.6kDa. Than a recombinant plasmid namedpPIC9K-cgc is structured to be transformed into Pichia pastoris GS115competentcells using electro transformation, and4Mut+positive transformants are selected.Between100kDa and60kDa on SDS-PSGE the target recombinant protein band isfound after induction and expression. The optimum temperature of Chaetomiumcupreum glucanase protein is about45℃, and the optimum pH is5.0. Its enzymeactivity of crude enzyme is0.128U in the optimum conditions. Rate of growthinhibition of germination of Fusarium oxysporum spore is11.8%in a concentrationof50%glucanase protein，which shows a potential theoretical and practicalsignificance in biological control of plant pathogen.