Studies on Red Pigments Production of Pseudomonas aeruginosa (Strain No. 145) (Report IV)

Abstract

The production of water-soluble, diffusible, red pigments from Ps. aeruginosa, strain No.145, maintained in our laboratory, have been previously reported.
The final color demonstrated in liquid or solid medium of a pigment producing strain, varies with a kind of its medium. Most of these strains produce yellow pigments at initial stage of thier pigmentation.
The culture of strain No.145, also gave a yellow color, but no fluorescent on the surface of its slant-fluid during the first several hours of incubation and in the deep-fluid culture within 72 hours.
This yellow color rapidly disappeared, and then turned to the red. In order to know the nature of this yellow pigment a study was first directed to its isolation.
The yellow compound having its absorption maximum at 440 mμcould be separated from the culture supernatants by column chromatography on Sephadex G-25 M.
A fractionated yellow pigment characterized as PII was converted to red with treating of some oxitdizing reagent such as hydrogen peroxide, but no changed with air. Moreover, this yellow pigment was decolorized by alkali and turned to deep yellow in acidic solution. On the other hand, yellow-culture supernatants containing PI pigment was gradually changed to the red with airation.
Yellow pigment showed a similar ultraviolet absorption spectra with that of PII and its oxidation product (red pigment) gave the same migration of electrophoresis with PII. And these three pigments have a specific absorption given by sixmembered nitrogen containing hetero-cyclic compounds respectively. As a precursor the yellow pigment have a close relationship to the PII, judging from thier appearance during fermentation process and comparison of thier properties.
From these results, this yellow pigment could be supposed as an intermediate of the red pigment. The yellow pigment might be related to PII as its precursor.
In the previous paper, it was reported that the red pigment designated as PI was supposed to be one of aminophenazine derivatives but not to be Aeruginosin isolated by F. G. Holliman. It is presumed that most of the red pigments produced by Ps. aeruginosa are probably phenazine derivatives having some different, auxiliary chromophores.