Antibacterial and technological properties of Lactococcus lactis ssp. lactis KJ660075 strain selected for its inhibitory power against Staphylococcus aureus for cheese quality improving

Traditional cheeses manufactured from goat’s milk in Algeria suffers from poor microbial quality, impairing both safety and shelf-life. Lactic acid bacteria may not only improve cheese quality, but also offer an alternative bioprotective approach to methods such as heating or addition of conventional perspectives. In this context, Lactococcus lactis ssp. lactis KJ660075 strain was studied. The bacterium had shown a remarkable antibacterial inhibition almost against several food borne pathogens and spoilage bacteria, but not against Lactobacillus plantarum . This antibacterial activity was attributed to proteinaceous molecule as its activity was lost with protease treatment. The anti- Staphylococcus aureus activity of the isolate was confirmed by co-culturing in ultrahigh temperature treated goat’s milk (reduction of 4 log cfu ml −1 ). Futhermore, the strain exhibited a good acidification kinetics, caseinolytic and lipolytic activities and moderate autolysis. Free amino acid analysis of model cheese manufactured with KJ660075 revealed the presence of compounds with organoleptic and health qualities.