Screening and detection of temperate bacteriophages in the starter cultures

Fermented dairy products are considered functional foods in many parts of the world. Fermentation failure in the dairy industry results in tremendous economic loss to the dairy industry and entrepreneurs. Therefore, this study was undertaken to investigate the prevalence of temperate bacteriophages in the cheese and yogurt cultures. Two tests were standardized and used to detect the presence of phages viz., double layer plaque assay and the spot test. Temperate phages were detected in the cheese and yogurt culture and confirmed to belong to the Siphoviridae family by morphological studies using transmission electron microscope. The study provides the scientific evidence creating awareness of the presence of temperate bacteriophages in the dairy starter cultures used in the production process of the fermented dairy products.