An actinomycete that changes wall composition during sporulation

Wall analyses on recently isolated strains of Willoughby's ‘spore-dome’ actino-mycetes grown in submerged culture would suggest that the peptidoglycan contained ll-diaminopimelic acid (ll-DAP) or meso-DAP or even mixtures of the two isomers. This chemotaxonomic paradox was explained when it was shown that the vegetative mycelium had walls containing ll-DAP and glycine (wall chemotype I) and that spores contained only meso-DAP as the diagnostic amino acid (wall chemotype III). Our earlier data had been obtained from preparations derived from biomass containing mixtures of spores and vegetative mycelium.