A rapid procedure for detection of bacterial amino acid decarboxylases

The detection of decarboxylases of arginine, glutamic acid, histidine, lysine, ornithine, phenylalanine, tryptophan, and tyrosine in bacteria by thin-layer chromatography on polyamide sheets is described. The bacteria were grown on agar medium plates supplemented with eight amino acids at pH 5.5 for induction of amino acid decarboxylases, then transferred to amine-production media. The decarboxylation products in the spent media (amines and/or γ-amino-n-butyric acid) were dansylated and the dansyl derivatives were separated by thin-layer chromatography on polyamide sheets. This method requires only two separate incubations of the decarboxylase-induced bacteria in amine-production media for 1 h at 37°C for simultaneous detection of eight bacterial amino acid decarboxylases using 0.4 μl of the spent media.