ISOLATION OF EXOPOLYSACCHARIDE – PRODUCING LACTIC ACID BACTERIA FROM TRADITIONAL EGYPTIAN DAIRY PRODUCTS

The present study aimed to isolate and characterize strains of exopolysaccharide (EPS)-producing lactic acid bacteria (LAB) from traditional Egyptian dairy products. A total of 388 suspected LAB isolates were recovered from 100 samples of traditional Egyptian dairy products including Kariesh cheese, Zabady, Laban Rayeb and Ras cheese. Out of these suspected LAB cultures, 123 and 27 isolates were identified as potential LAB cocci and lactobacilli, respectively. These 150 LAB isolates were further examined for their ability to produce exopolysaccharides (EPS) in milk. Only 7 LAB isolates were found to produce EPS. These isolates were cultured form Laban Rayeb (3 isolates) and Zabady (4 isolates). A PCR identification procedure was carried out to identify these EPS- producing isolates to the species level. All the 7 isolates were found to belong to Streptococcus thermophilus. These results generally suggest the possibility of using Egyptian dairy products as a source of EPS-producing LAB.