The Expression of GroEL Protein Amplified fromBifidobacterium animalissubsp.lactisKLDS 2.0603 and its Role in Competitive Adhesion to Caco-2

Bifidobacteria are beneficial microorganisms dominantly present in the gastrointestinal tract and provide numerous nutritional and health benefits to the host. Colonization to the mucosal surface is the foundation to execute bifidobacterial probiotic functions. Mechanisms of adhesion between bifidobacteria and the host are still not clear; however, the surface-associated proteins of the bacteria play a significant role. In our previous study, GroEL protein was speculated to be participating in the bifidobacterial adhesion to the epithelial cells. In the present work, we have focused on determining the function of GroEL protein in inhibiting the bacterial adhesion to Caco-2 cells. We cloned groEL gene and constructed an expression plasmid pQE-30-groEL. IPTG was used to induct the GroEL protein in Escherichia coli M15 and the GroEL protein was purified by affinity chromatography. Results showed that the recombinant GroEL protein inhibited bacteria bound to Caco-2 cells in a dose-dependent manner. Above all, GroEL was indicated to be an adhesion factor in bifidobacteria.