APPLICATION OF BACTERIOCIN-PRODUCING LACTIC ACID BACTERIA ISOLATED FROM SALTED DRIED CAMEL MEAT (EL KADID) IN THE PRESERVATION OF GOAT CHEESE AGAINST Staphylococcus aureus

Abstract

El kadid is a traditional North African food obtained by natural dehydration of One-humped camels (Camelus dromedarius) meat still produced through traditional method in Algeria. This traditional food matrix constitutes a rich ecological niche for the screening of bacteriocin-producing strains and lactic acid bacteria which contributes to the safety and preservation of foods. Fifteen lactic acid bacterial isolates from El kadid were tested for antibacterial activity and biopreservative effectiveness against Staphylococcus aureus. Only four strains exhibited bacteriocin activity against the two indicator bacteria, Listeria monocytogenes ATCC 4379G and Staphylococcus aureus ATCC 25923, in the neutralized cell-free supematant treated with catalase and proteolytic enzymes. Strain LB6, identified as Lactobacillus plantarum and characterized by the highest antimicrobial activity, was selected for further trials. Bacteriocin rate peaked during the stationary phase. The ideal temperature and pH for its formation were 37°C and 6.5, respectively. The bacteriocin was stable at high temperatures (30 min at 100°C) and active following incubation at pH levels ranging from 2 to 12. This strain showed high activity in fresh goat cheese (11–15 mm inhibition zone) having the ability to prevent the development of S. aureus, also reducing the inoculum level of pathogen by about 1 log cycle. These results revealed that this strain could be a promising biopreservative starter for the dairy industry. To the author ’s knowledge, this is the first report of L. plantarum being isolated in salted dried camel meat.