A Study of the Moraxella Group II. Oxidative-negative Species (Genus Acinetobacter )

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Abstract
A number of nutritional and biochemical properties of more than 100 strains of the oxidase-nega-tive moraxellas (the Mima-Herellea-Acinetobacter group of bacteria) were studied. These properties included the range of C sources that can support growth, the utilization of nitrate, the production of proteolyt-ic and lipolytic enzymes and the reactions involved in the oxidation of sugars and aromatic compounds. No evidence could be obtained for the accumulation of either poly-B-hydroxybutyrate or polysaccharide as intracellular reserve materials. Of 158 different compounds tested, the group as a whole could use 85 as sole C sources for growth. The nutritional spectra of the individual strains has a range of from 17-74 alternative substrates. On the basis of 56 selected nutritional and physiological characters used for a numerical analysis, the collection could be divided into 2 major groups of strains comprising at least 7 less clearly defined clusters. Neither the hydrolysis of gelatin or acid production from aldose sugars were a reliable index of strain affinities indicated by the phenotypic analysis, although both properties were of some use in distinguishing between the subgroups. For the reasons discussed, the authors propose that the oxidase-negative moraxellas be placed in the genus Acinetobacter Brisou and Prevot, for which a modified description is presented. A. calco-aceticus (Beijerinck) is proposed as the type species, of which antitratum is regarded as a synonym or variety. On the basis of the present studies and unpublished supporting evidence provided by M. Mandel on DNA composition and by J. Johnson on DNA homologies, it is proposed that 2 other species in the genus, A. lwoffi (Audureau) and A. hemolysans (Henriksen), as well as 1 subspecies, A. hemolysans haemolyticus (Stenzel and Mannheim), be recognized provisionally.