Abstract: Lactococcus lactis, an important model strain for industrial applications, is an ideal host for heterologous protein expression and secretion because of its non-pathogenic nature, high protein secretion capacity and easy isolation and culture. An efficient and controllable promoter is one of the key factors for efficient expression of exogenous proteins. According to the induction mechanism, promoters can be divided into constitutive promoters and inducible promoters. This paper introduces the structure of Lactococcus lactis expression systems and Lactococcus lactis promoters, summarizes the bioinformatics methods to predict promoters and the new promoter screening cloning methods, and provides an outlook on future directions for research on Lactococcus lactis promoters. We believe that this review will lay the foundation for further research on the structure and function of promoters and industrial production of exogenous proteins.

Key words: Lactococcus lactis; expression system; promoter