CHEMISTRY OF CELL WALLS 27 



TABLE 8 



The Percentages of Various Polysaccharide-Protein Complexes in 

 the Walls of Several Yeasts * 



Recoveries of Cell Wall Complexes 



Glucan Glucomannan- Glucomannan- 

 Protein Protein I Protein II 



Organism % % % 



* From the data of Kessler and Nickerson.^ 



Chemistry of Bacterial Cell Walls 



In discussing the chemistry of bacterial cell walls, it be- 

 comes necessary to distinguish between the two major 

 groups of organisms differentiated by the Gram stain re- 

 action. Early comparative studies of wall composition indi- 

 cated the greater complexity of the walls isolated from 

 Gram-negative bacteria. ^^-^^ This chemical heterogeneity 

 was later found to be paralleled by a more complicated 

 physical structure of multilayered walls with macromolecu- 

 lar subunits, as mentioned in Chapter 1. Whether the 

 greater chemical complexity of the "wall" of Gram-negative 

 bacteria is due to the presence of a single structure possess- 

 ing the functional units of a true wall and a membrane has 

 not been satisfactorily resolved. However, the thin sections 



