Studies on the Cell-Wall Composition and Taxonomy of Actinomycetales and Related Groups

Abstract

The cell-wall compositions of 51 strains of Actinomyces, Nocardia, Streptomyces, Micromonospora, Mycobacterium and Propionibacterium have been investigated, together with those of 7 strains of Eumycetes. The cell walls of the actinomycetes were made up of sugars, amino sugars and amino acids (the latter few in number). The general pattern of components was thus identical with that previously found for Gram-positive bacteria. In the fungi, however, the mycelial walls were composed entirely of carbohydrate. These results suggest that the actinomycetes are not related to the fungi but should be classified with the bacteria proper. On the basis of cell-wall composition a classification of the actinomycetes is proposed, to consist of 3 families : Mycobacteriaceae containing the genera Mycobacterium, Nocardia and Corynebacterium; Streptomycetaceae containing Streptomyces and Micrmnospora ; and Actinomycetaceae with a single genus Actinomyces. The propionibacteria are probably related to Streptomyces. It is also suggested that a separate order Actinomycetales is unnecessary and that the families proposed can more suitably be included in the Eubacteriales.

Cell Wall Composition in Mycobacterium lepraemurium

“…samples A and D. Table I . This parallels similar findings for other mycobacteria (see Cummins & Harris, 1958;Cummins, 1962). However, during the present work it was noticed that cell-wall suspensions prepared in a sucrose gradient after disintegration of freshly made suspensions of M. Zepraemurium were stable in saline and gave a titre against M .…”

“…The principal amino acids found were alanine, glutamic acid and DAP, the latter the DL-isomer (or DL+DD), and the principal sugars identified were arabinose and galactose, with a trace of mannose. This pattern of sugar and amino acid components is that to be expected in a mycobacterium (Cummins & Harris, 1958;Cummins, 1962). The identity of the hesoxamines is not known for certain, since the chromatographic method used did not separate glucosamine and muramic acid, but it may be assumed that both are present.…”

“…Examination of cell wall fractions prepared from a number of strains of mycobacteria have shown a common pattern of components which these organisms share with strains of nocardia and some corynebacteria (Cummins & Harris, 1958 ;Cummins 1962). This common pattern is characterized by the presence of the sugars arabinose and galactose, and of alanine, glutamic acid and DL-diaminopimelic acid as mucopeptide amino acids.…”

Serological Relationships of Corynebacteria

“…1959;Cummins, 1962a, b ;Cummins & Harris, 1956, 1958Perkins & Cummins, 1964;Barber et al 1965bBarber et al , 1966 …”

ULTRASTRUCTURE OF NOCARDIA ASTEROIDES AS REVEALED BY ELECTRON MICROSCOPY

“…However, on the basis of cell wall composition, Cummins and Harris (10) proposed that the actinomycetes are not related to the fungi and should be classified with bacteria proper. They also suggested that Nocardia is more closely related to Mycobacterium than to Streptomyces.…”