44 MICROBIAL CELL WALLS 



complex,^2 suggesting a firm chemical combination between 

 the polysaccharide and the rest of the wall (as for Strepto- 

 coccus faecalis ^^). Further evidence establishing the pres- 

 ence of mucopolysaccharides in the walls has come from the 

 investigation by McCarty ^^ of the products of enzymic di- 

 gestion of Group A streptococcal walls. The "C" carbo- 

 hydrate fractions from the streptococcal wall still contained 

 small residues of peptide but were composed predominantly 

 of amino sugar and rhamnose.*^^ Further fractionation 

 failed to remove the peptide constituents, and there seems 

 little doubt that these mucopolysaccharides were joined to 

 the mucopeptides in the original wall. 



Teichoic Acids. Mitchell and Moyle ^^ reported the pres- 

 ence of a poly glycerophosphate compound in the envelope 

 of Staphylococcus aureus, and the status of this material as 

 a wall component remained uncertain until the problem 

 was taken up again following the discovery by Baddiley 

 and his colleagues ^^ of the two nucleotides, cytidine diphos- 

 phoglycerol and cytidine diphosphoribitol. It will be re- 

 called that the wall of Bacillus suhtilis had a very high phos- 

 phorus content (see Table 9), and it was not surprising that 

 an examination of the wall of this organism and that of 

 Lactobacillus arabiiiosus [syn. Lactobacillus plantarum] 

 (the organism from which the two nucleotides were isolated) 

 revealed the presence of ribitolphosphate polymers. ^^ No 

 glycerophosphate polymer was detectable in the walls of 

 either of these organisms. The name teichoic acids was 

 given originally only to the ribitolphosphate polymer,-^ but 

 since the confirmation of the presence of a glycerophosphate 

 polymer in walls of other bacteria, and the detection of 

 both types in yet others, the term teichoic acids has been 

 extended to include both types of polyols.*^^ The distribu- 

 tion of the two types of teichoic acids in various cell walls 



