Effect of exopolysaccharides (EPSs) produced by Lactobacillus delbrueckii subsp. bulgaricus strains to bacteriophage and nisin sensitivity of the bacteria

• Published in: Food science & technology 2007-04, Vol.40 (3), p.564-568
• Main Authors: Durlu-Özkaya, Fügen, Aslim, Belma, Taha Ozkaya, Mucahit
• Format: Article
• Language: English
• Subjects: Bacteria; Bacteriophage; bacteriophages; Biological and medical sciences; Exopolysaccharides; Food industries; Food microbiology; frozen yogurt; Fundamental and applied biological sciences. Psychology; isolation; lactic acid bacteria; Lactobacillus; Lactobacillus delbrueckii; Lactobacillus delbrueckii subsp. bulgaricus; molecular sequence data; Nisin; nucleotide sequences; polysaccharides; raw milk; skim milk
• ISSN: 0023-6438; 1096-1127
• DOI: 10.1016/j.lwt.2005.09.009

Lactobacillus strains used in this study were isolated from village-type yogurt and raw milk. The isolates were identified as Lactobacillus delbrueckii subsp. bulgaricus by 16 s rDNA sequence analysis and API 50 CHL identification systems. The exopolysaccharide (EPS) production of the strains growth in skim milk were investigated. In addition sensitivity and insensitivity of these strains against domestic bacteriophages and nisin were examined. It was deduced that those strains which had relatively high EPS-producing capacity were insensitive against phages and nisin. Linear relationships were determined between EPS production of the bacteria and bacteriophage and nisin insensitivity of the bacteria. There was a negative correlation between EPS production quantity and phage and nisin sensitivity of the bacteria. Of all the strains, L. delbrueckii subsp bulgaricus B3 produced the highest EPS quantity, and it was insensitive against phages and nisin. Based on these results, it is suggested that L. delbrueckii subsp bulgaricus B3 can be used with the starter culture in dairy industry for stable and high-quality yogurt production.