A Proposed Biochemical Basis for the Genus Pseudomonas

Abstract

It is suggested that the genus Pseudomonas should comprise those rod-shaped bacteria which produce phenazine pigments, regardless of the color of the pigments, or water-soluble, fluorescent pigments, or both. Since pathogenicity is not a very satisfactory taxonomic criterion, fluorescent plant-pathogens of the present genus Phytomonas of the Bergey system might well be included in the genus Pseudomonas as redefined. Bacteria definitely known to produce phenazine pigments are Ps. aeruginosa (Bacillus pyocyaneus), Ps. chlororaphis (B. chlororaphis), and Ps. clemoi (Ps. iodina or Chramobacterium iodinum), but many other bacteria produce pigments whose properties suggest that they are phenazine derivatives, and they should be tentatively classed under Pseudomonas pending chemical work on their pigments. Ps. beijerinckii and Ps. indigofera (B. indigoferus) produce pigments which are not phenazines, and should be excluded from the genus Pseudomonas. 28 references.