The decarboxylation of tyrosine by certain enterococci strains leads to the undesirable presence of tyramine in fermented foods. Tyramine is the most frequent biogenic amine found in cheese and is also commonly found in other fermented foods and beverages. In total 75 different strains of enterococci from various dairy products were studied. A multiplex PCR was designed for the genotypic differentiation of various enterococci strains and to determine the presence to tyramine producing (tyrdc) gene. E. faecalis followed by E. faecium was found to be the most prominent strains present in dairy products. Presence of E. mundtii, E. malodoratus, E. durans, E. casseliflavus, E. raffinosus was also found but to a lesser extent. 82% of the total strains were found to be carrying tyrdc gene responsible for tyramine production. E. faecalis was found to be the most active and E. casseliflavus was found to be the least active in the production of tyramine.

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