Identification of Lactic acid bacteria and detection of bacteriophage in raw cow milk and halloumi cheese

Abstract

The diversity of Lactic acid bacteria (LAB) in raw milk and cheese sample was investigated in this study. Two samples of raw milk and halloumy cheese were studied. LAB isolated from these two samples were identified. Five species were found in milk samples that includes Lactobacillus delbrueckii, Lactococcus Lactic, Streptococcus thermophillus, Lactobacillus paracasei and Leuconostcmesenteroidescreomris.Six species were detected in halloumy cheese that includes: Lactobacillus rhamnosus, Lactobacillus plantarum, Lactobacillus paracasei, Lactobacillus fermentum, Lactobacillus pentosus, andLeuconostocmesenteroidescremoris.Milk sampleswere then analyzed for the presenceof bacteriophages and no bacteriophage was found.Moreover, the bacterial strains identified in this study were investigated for the presence of temperate phages by induction with mitomycinC.Only Lactococcuslactisisolated from milk samples was found to carry bacteriophages in its genome. Lysogenic lactic acid bacteria may lead to fermentation failure and thus represent a high risk for the dairy industry.