To develop a new type of chilled pork preservative,we isolated a strain from forest soil,which exhibited a broad bactericidal activity against seven spoilage and food-borne pathogens bacteria commonly related to pork,including Brochothrix thermosphacta,Listeria monocytohenes,Staphyloccocus aureus,Lactococcus lactis,Pseudomonas fluorescens,pathogenic Escherichia coli and Salmonella paratyphi.We ruled out the inhibition due to lactic acid and hydrogen peroxide.We further studied the individual and colony morphology features,physiological and biochemical characteristics,the sequence features of the 16S rDNA and the species-specific N-acetylmuraminidase gene(acmA) of this strain.Consequently,it was identified as Lactococcus lactis subsp.lactis,named as NFL.Uniquely,the inhibitory agent was thermally stable up to 121°C for 90 min.Fermentation filtrate of strain NFL sterilized at 121°C for 20 min had obvious fresh-keeping effect on chilled pork with tray package,especially significantly reduced rancidity.So,Lactococcus lactis NFL was a potential food preservative-producing strain,especially for chilled pork and pork products fresh-keeping.