Research of β-1，4-endoglucanase Gene Secreting Expression in Escherichia coli

Abstract:

This study constructed a secretive recombinant plasmid pMG36e-usp45-egl3 and E. coli DH5α/pMG36e-usp45-egl3 with a fusion gene usp45-egl3 connected by the secreted protein gene sequence of usp45（81 bp） from Lactococcus lactis and the coded mature-protein gene sequence of egl3（657 bp） from Trichoderma reesei by the method of overlapping extension PCR. After analyzing the expressive effect of recombinant Escherichia coli and evaluate the capability of secreted β-1，4-endoglucanase degrading fiber. The results showed that the recombinant E.coli DH5α/ pMG36e-usp45-egl3 could secrete β-1，4-endoglucanase with activity of 226 mU/mL after culture 14 h and effectively degrade sodium carboxymethylcellulose. The rate of β-1，4-endoglucanase degrading sodium carboxymethylcellulose into reducing-sugar was 2.35 mg/（h·mL）.