Comparison of the Cell-Wall Composition of Morphologically Distinct Actinomycetes

Abstract

Cell-wall composition of various morphologically distinct Actinomycetes was studied to determine the relationship, if any, between cell-wall composition and morphological criteria in Actinomycete taxonomy. The methods used were similar to those of Cummins and Harris. Five types of cell-wall composition were obtained; however, these were not always correlated with groupings by the conventional classification system. For instance, the sporangium-forming Actinomycetes, Actinoplanaceae, had three types of cell-wall composition; the composition of cell walls of Promicromono-spora, Micromonospora, and Microbispora was the same as, or similar to, that of Actinomyces, Actinoplanes, and Streptosporangium, respectively; Chainia, Actinopycnidium, Actinosporangium, and Micro-ellobospora had the same cell-wall composition as Streptomyces, whereas that of Streptoverticillium was slightly different. Possible implications of cell-wall composition and morphological differentiation of hyphae for the taxonomy and phylogeny of Actinomycetes are also discussed.