Amino acid requirement of six strains of Listeria monocytogenes.

Different serovars of Listeria monocytogenes grew well in a chemically defined medium. Sixteen amino acids were tested for the growth of L. monocytogenes. Most strains required cystine, valine, isoleucine, and leucine. Phenylalanine was a stimulatory growth factor for all six strains of Listeria. Whilst tryptophan was essentially required by NCTC 7973, LM and C-286 and stimulatory for 4155 and C-294, none of the strains did exhibit requirements of asparagine, glutamine, proline, histidine and tyrosine as essential/stimulatory growth factor.