Construction of a Strain of Recombinant Lactococcus lactis Expressing Food-Grade Nattokinase

An integrative expression vector designated as pFY008 was constructed with HisH gene as a homologous recombination target site.For food-grade expression of nattokinase gene(aprN) in Lactococcus lactis,the expression cassette PnisA-aprN gene was integrated into the genome of Lactococcus lactis by homologous recombination.A food-grade recombinant Lactococcus lactis was constructed to produce a thrombolytics protein.The recombinant Lactococcus lactis was found to have fibrinolytic activity.Meanwhile,it had fine stability and high safety.