Influence of lactic acid bacteria isolates on staphylococcus aureus growth in skimmed milk

Abstract

A total of 52 lactic acid bacteria (LAB) isolates was isolateded from acidcoagulating cheese samples one day old. The samples made from raw cows milk were collected from the houshold of an individual producer in Belgrade surroundings. The isolates were identified as Lactococcus spp.(43.39%) and Lactobacillus spp. (54.71%) and were selected for additional identification. Out of 23 Lactococcus spp. isolates, by monitoring 24 different morphological and physiological characteristics, 18 (78.26%) isolates were identified as Lactococcus lactis subsp. cremoris, 2 (8.69%) isolates as Lactococcus lactis subsp.lactis, 2 (8.69%) isolates as Lactococcus plantarum and 1 (4.35) isolate as Lactococcus lactis subsp. rafinolactis. Out of 29 Lactobcillus spp. isolates from acidcoagulating cheese were observed for 19 different morphological and physiological properties; 9 (31.03%) isolates were identified as Lactobacillus plantarum, 4 (13.79%) isolates as Lactobacillus brevis, 3 (10.34%) isolates as Lactobacillus buchneri, 3 (10.34%) Lactobacillus salivarius subsp. salivarius, 3 (10.34%) isolates as Lactobacillus acidophilus, 2 (6.89%) isolates as Lactobacillus paracasei subsp. tolerans, 2 (6.89%) isolates as Lactobacillus leichmanii, 1 (3.45%) isolate as Lactobacillus delbrueckii subsp. delbrueckii and 1 (3.45%) isolate Lactobacillus delbrueckii subsp. bulgaricus. An inhibitory effect of LAB on Staphylococcus aureus growth was observed in skimmed milk. The resulting inhibition can be ascribed to the lowering of pH.