**4. Conclusion**

Surface display is an attractive technology that can be used to confer new functions to LAB. The effectiveness of these systems depends on the appropriate selection of several factors including the anchoring domains, secretion signals, and host strains. Moreover, a proper strategy for the fusion of anchoring domains to target proteins should be determined to protect the functionality of target proteins. So far, a limited number of surface display systems have been developed. The characterization of anchoring, secretion, and regulatory signals from genome sequences can expand the surface display systems. The low transformation efficiency of LAB is a major obstacle for the construction of surface display systems and the establishment of efficient transformation protocols is therefore necessary.
