ISOLATION AND PROPERTIES OF WALLS 21 



TABLE 7 

 Chemical Constituents of Microbial Walls 



Bacteria 



Eubacteria 



Gram-positive Mucocomplex (mucopeptides, mucopoly- 



saccharides) and teichoic acids 

 Gram-negative Protein, polysaccharide, lipid, 



mucocomplex constituents 

 Myxobacteria 



Myxococcus xanthus Protein, lipid, polysaccharides, 

 mucopeptides, carotenoids 

 Blue-Green Algae 



Anacystis nidulans \ 



Microcoleusvaginatus\^^'''^''P^P''^^ constituents, carotenoids 



Nostoc sp. Protein 



References 45, 48, 50, 61-63 



number of microorganisms are predominantly polysaccha- 

 ride they contain in addition significant protein and lipid 

 constituents. Furthermore, the investigations of Nickerson 

 and his colleagues ^^-^^ have shown that in the yeast wall 

 glucans and mannans occur as protein complexes and that 

 they are not present as simple polysaccharides. 



Comparative studies of cell-wall chemistry have also estab- 

 lished the presence of a new type of structural heteropoly- 

 mer, the mucocomplexes,^^ in walls of all bacteria so far 

 examined, and in many of the Gram-positive bacteria they 

 constitute the entire wall. The essential similarity of this 

 class of cell-wall substance to other mucopolysaccharides 

 was first pointed out as a result of the investigations of the 

 wall of Streptococcus faecalis (Salton '^^), and their distinc- 

 tion from known mucoproteins was also emphasized. This 



