Production Optimization of an Active -Galactosidase of Bifidobacterium animalis in Heterologous Expression Systems

Figure 1

Electrophoresis analysis of recombinant bG42-106 expressed in E. coli. (a) SDS-PAGE profiles of recombinant bG42-106. Lanes: M, the protein molecular mass standards; 1, the lysate of induced E. coli BL2(DE3) harboring empty pET-30a(+); 2, the intracellular protein of uninduced E. coli BL21(DE3) harboring pET-bg42-106; 3, the intracellular protein from E. coli BL21(DE3) harboring pET-bg42-106 with IPTG induction (4 mM and 28°C for 4 h); 4, the proteins eluted in 200 mM histidine wash from the Ni²⁺-NTA affinity resin. The arrow indicates the position of recombinant bG42-106. (b) Activity staining of purified bG42-106 on nondenaturing polyacrylamide gel. Lanes: M, the protein molecular mass standards; 1, purified bG42-106 from E. coli.

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