CHARACTERIZATION OF A PIGMENT PRODUCED BY PSEUDOMONAS-FLUORESCENS DURING 3-CHLOROBENZOATE CO-METABOLISM

A strain of Pseudomonas fluorescens, designated CP30, was found to be able to co-metabolize 3-chlorobenzoic acid via 3-chlorocatechol and 4- chlorocatechol. These two intermediates seem to be involved in the dar kening of the medium. The black pigments produced, which were recovere d and purified from the CP30 cells and culture broth, have a number of chemical and spectroscopic characteristics typical of polyphenols. Th e analytical data and the results obtained from chemical degradation s tudies suggest that the structure of these halogenated bacterial pigme nts is closely related to that of the ''catechol-melanins'' of the pla nt kingdom described until now. Comparative chemical studies, includin g both bacterial pigments and 4-chlorocatechol polymers prepared in vi tro, supported the hypothesis that CP30 pigments are ''chlorocatechol- melanins''. The production of the pigment seems to be responsible for a substantial modification of the CP30 cell shape.