Surface Anchoring on Lactococcus lactis by Covalent Isopeptide Bond

Display of recombinant proteins on the bacterial surface is an emerging research area with wide range of potential biotechnological applications. Because of its GRAS (generally recognized as safe) status, lactic acid bacterium Lactococcus lactis represents an attractive host for surface display and promising vector for in situ delivery of bioactive proteins. The present study focused on finding a new alternative approach for surface display on Lactoccocus lactis. We developed a system that enables the formation of irreversible isopeptide bonds on the surface of Lactococus lactis. This was achieved through the following two protein/peptide pairs, SpyCatcher/SpyTag and SnoopCatcher/SnoopTag.1-3 Attachment of tagged model protein B domain to the cell surface of Lactococccus lactis displaying the corresponding catcher protein was demonstrated using flow cytometry. We demonstrated effective use of aforementioned protein anchors which thus represent a promising alternative to established approaches for surface display on Lactoccocus lactis.