Molecular diagnostic of streptococcus thermophilus

Abstract

Streptococcus thermophilus is one of the most important lactic acid bacteria in the dairy industry. Despite the wide use of Streptococcus thermophilus in the industry, data on the phenotypic and genetic strain variations within the species are still limited. Genetic techniques are very useful for molecular discrimination of complex mixtures of starter and probiotic cultures in research laboratories. Detection and identification of various lactic acid bacteria species with rapid methods is often important for quality control of dairy products. This work deals with characterization and differentiation of strains Streptococcus thermophilus by PCR, RAPD and SDS-PAGE techniques. Fifteen strains of Streptococcus thermophilus from Czech Collection of Dairy Microorganisms (CCDM) and a strain of Streptococcus thermophilus from Czech Collection of Microorganisms (CCM) were used. Particular strains were confirmed with primer set THI/THII by PCR method. Consequently, their identities were examined by RAPD and SDS-PAGE techniques. Whereas, primers OPP-7 and RAPD-4, RAPD were used. It can be claimed that mentioned methods are good means for identification and characterization of streptococci.