None of the tested strains was able to produce
β-phenylethylamine under the present assay conditions. No
specific phenylalanine decarboxylases have been described,
but several authors have reported that certain tyrosine
decarboxylases can use phenylalanine as an alternative substrate,
converting it into β-phenylethylamine [53]. In the
present work, only the E. faecalis positive control was able
to produce β-phenylethylamine in medium supplemented
with tyrosine (data not shown)