An Attempt At Grouping Of The Genus Pseudomonas

Abstract

The generic name of Pseudomonas was given by MIGULA (1) in 1894 to the group of bacteria which were GRAM negative rods possessing polar flagella. Ps. aeruginosa was chosen as the type species. The beautiful greenish yellow fluorescent pigments are produced by some species. Pseudomonads are widely distributed in nature, and are isolated from many sources, such as river water (2,3), sewage, beer (4), maple sap (5), dairy products (6), cereals (7), petroleum (8), natural gas brine (8), etc. The generic concept of Pseudomonas has been mainly based upon cell morphology, flagellation, and GRAM stain, and it includes the largest number of species in Pseudomonadaceae. MIGULA (9) divided this genus into five groups based upon the characteristics of pigmentation. In both BERGEY'S (10) and KRASSILNIKOV'S manuals (11), the production of pigments is used for the differential key of this genus. However, the pigmentation was chosen merely for the sake of convenience, and its taxonomical value was not critically evaluated. Although the significance of some taxonomical characteristics of this genus has been reported by several investigators (12-16), the number of strains and species studied was too limited to cover the whole generic group. In the present paper, the authors describe the results of comparative and systematic studies on the physiological, biochemical and ecological features of Pseudomonas strains, which led to the conclusion that taxonomically the genus should be divided into three groups on the basis of the characteristics of pigmentation. Details on the systematic of this genus will be reported elsewhere. © 1963, Applied Microbiology, Molecular and Cellular Biosciences Research Foundation. All rights reserved.