PIGMENTATION AND TAXONOMY OF THE GENUSXANTHOMONAS

Abstract

Starr, MortimerP. (University of California, Davis),and William L. Stephens. Pigmentation and taxonomy of the genusXanthomonas. J. Bacteriol.87:293–302. 1964.—The colonies formed by phytopathogenic bacteria of the genusXanthomonasare typically yellow in color. This chromogenesis stems from the presence in all yellow xanthomonads of a particular carotenoid pigment. This unique “Xanthomonas-carotenoid,” which has not been found in any yellow nonxanthomonad, is characterized herein to the extent required for its recognition by relatively simple screening procedures. In general, the occurrence of a carotenoid “alcohol” with absorption maxima at 418, 437, and 463 mμ (petroleum ether)—in a gram-negative, polarly-flagellated, oxidative, rod-shaped bacterium—would suggest placement of that microorganism in the genusXanthomonas.