Cloning and Expression of Aspergillus Niger β-Glucosidase Gene in Escherichia Coli

According to the sequence of Aspergillus niger β-glucosidase gene published in GenBank,two pairs of specific primers were designed and synthesized.Using the total RNA and genome DNA of Aspergillus niger H7 as template,bgl gene and exon 5 sequence were amplified.PCR product were then cloned into pMD18-T vector and sequenced,the results showed the nucleoside sequence of bgl was 2583 bp,the homology of target gene and its deduced amino acid sequence to the published could reach 99% and 99%,respectively.E5 sequence was 100% identical to the exon 5 region of bgl.Then the expression vectors pET32a(+)-bgl,pET32a(+)-E5,pET28a(+)-E5 were constructed and transformed into Escherichia coli BL21(DE3).The recombinant strains were induced by 1 mmol·L-1 IPTG and the target proteins were analyzed by SDS-PAGE.