Micropolyamide Thin-layer Chromatography of Fluorescein-thiohydantoin-Amino Acids at Picomole Level

The formation of aromatic l-amino acid decarboxylase in bacteria was studied with intact cells in a reaction mixture containing the aromatic l-amino acids, 3,4-dihydroxy-l-phenyl-alanine, l-tyrosine, l-phenylalanine, l-tryptophan and 5-hydroxy-l-tryptophan. Activity was widely distributed in such genera as Achromobacter, Micrococcus, Staphylococcus and Sarcina. Bacterial strains belonging to the Micrococcaceae showed especially high decarboxylase activity toward l-tryptophan, 5-hydroxy-l-tryptophan and l-phenylalanine. M. percitreus AJ 1065 was selected as a promising source of aromatic l-amino acid decarboxylase. Results of experiments with this bacterium showed that the aromatic amine formed from l-tryptophan by the enzymatic method was identical with tryptamine. M. percitreus constitutively produced an enzyme which exhibited decarboxylase activity toward l-tryptophan. However, when large amounts of the aromatic l-amino acids listed above or the tryptamine formed from l-tryptophan were added, enzyme formation was repressed.

Cells with high enzyme activity were prepared by cultivating this bacterium at 30°C for 24 hr in a medium containing 0.5% glycerol, 0.5% yeast extract, 0.5% Polypepton, 3.0 vol % soybean protein hydrolyzate, 0.1% KH₂PO₄, 0.1% MgSO₄ · 7H₂O, 0.001% FeSO₄ · 7H₂O and 0.001% MnSO₄ · 5H₂O in tap water (pH 8.0).