Functional expression and secretion of basic fibroblast growth factor in Lactococcus lactis

We have generated a recombinant <i>L. lactis</i> strain and an optimal expression strategy to enable the production of secreted bioactive growth factors. Our results demonstrate that this system can produce FGF2 which were able to promote the proliferation of fish Anguilla japonica pre-adipocytic cells. Despite minimal purification beyond affinity purification and buffer exchange, we were able to obtain comparable specific activity to commercial FGF2. The final yields can be derived at 1.97 mg/L and through simple protein purification and buffer exchange. Finally, this study highlights the potential use of <i>L. lactis</i> secretion as an endotoxin-free alternative, compared to <i>E. coli</i>, for production of growth factors for use in cultivated meat production.