Spectral properties of a mixture of fluorescent pigments produced by Pseudomonas aeruginosa.

The major chromophore of a mixture of fluorescent pigments produced by Pseudomonas aeruginosa ATCC 9027 had pH-dependent absorption, excitation, and emission spectra, such that two ionic forms existed in the ground state and three in the excited states. The pigments could complex with several metal ions to change fluorescence and absorption spectra. Although the pigments were separable into several components, spectra indicated that the same fluorescent chromophore was present in each component. Hydrolysis of the mixture of pigments gave amino acids which did not include alanine or lysine. These pigments must therefore differ from those described by other workers, even though similarities of the chromophores were evident from comparisons with data in the literature, and from comparisons of a hydrolytic product of the mixture of pigments, termed compound F, with the chromophore of the fluorescent pigment of Azotobacter vinelandii. Drastic hydrolysis of the latter chromophore also yielded compound F.