Abstract: To improve the enzyme activity of β-glucosidase, two β-glucosidase genes from Bacillus polymyxa were introduced separately (bglA and bglB) and together (bgl) into the pET-28a vector and expressed in Escherichia coli C41. The three recombinant strains were designated as EA, EB, and co-expression EAB. Strains EA and EB were mixed at ratios of 1∶1, 1∶2, and 2∶1 and their total β-glucosidase activity was compared with those of each single enzyme group, the co-expression strain, and mixed expression strains. The results of SDS-PAGE analyses showed that both BglA and BglB were 50 ku, and the size of these proteins in the EA and EB mixed cultures was also 50 ku. The size of Bgl in the co-expression strain EAB was 100 ku. These results indicated that a Bgl complex was able to form in cells, but not in vitro. In an enzyme activity assay, the activity of Bgl from the co-expression strain was not significantly different from that of bgl in B. polymyxa, but it was significantly higher than those of BglA in EA and BglB in EB (P<0.05). The results of Congo red staining also showed that the enzyme activity of Bgl was significantly higher than those of BglA and BglB. This study lays the foundation for the construction of artificial assemblies, and for the integration of biological technologies in cellulose processing.