Characterization of a pigment from a pseudomonad.

The chloroform-soluble pigments of various pseudomonads have been found to be phenazine derivatives (Clemo & Daglish, 1950; Hillemann, 1938; Kogl & Postowsky, 1930; Kluyver, 1956; Haynes et al. 1956), whereas the constitutions of water-soluble fluorescent pigments of various pseudomonads are not well known. This has been mainly due to the failure of previous attempts to obtain the pigments in a highly purified or in a crystalline state (Elliott, 1958). By using an adsorbent different from those of previous workers and finally by electrophoresis over a cellulose bed, it has been possible to isolate in crystalline state a watersoluble yellow-green fluorescent pigment from a pseudomonad and this compound appears to be a pteridine derivative. The pteridine nature of such water-soluble fluorescent pigments was also suggested by Giral (1936). The present paper is concerned with the method of isolation and the chemical nature of the fluorescent pigment.