[Construction of cell surface display system in lactic acid bacteria by using ice nucleation protein].

Objective: The gene of ice nucleation protein (INP), an outer membrane of Pseudomonas syringae was tested to display foreign proteins on the surface of Lactococcus lactis.
Methods: Plasmids pHZ101 and pHZ102 were constructed using gfp (Green Fluorescence Protein) as the reporter gene and N-terminal and NC-terminal of inp as the anchoring units. Plasmids pHZ101 and pHZ102 were subsequently transformed into Escherichia coli JM109 and Lactococcus lactis MG1363.
Results: Fluorescence microscope shows that green fluorescence was observed in both recombinant E. coli and L. lactis strains. Western blot indicated that GFP was expressed in both recombinant E. coli and L. lactis strains. INPN-GFP was mostly trapped in cytoplastic fraction while INPNC-GFP was mainly targeted on the cell membrane of L. lactis.
Conclusion: The results suggest a new way to construct cell surface display system of lactic acid bacteria by using ice nucleation protein.