16 



MICROBIAL CELL WALLS 



TABLE 2 

 Cell-Wall Thickness and Contribution to Cell Dry Weight 



* Based on 90% recovery of various fractions from disintegrated 

 yeast. 



References 1, 24, 29, 39, 40, 43, 45. 



have clearly shown that the nutritional status of the organ- 

 ism is of some importance in governing the amount of wall 

 formed. When Streptococcus jaecalis was grown under con- 

 ditions of threonine depletion, the wall accounted for as 

 much as 44% of the weight of the cell. No detailed investi- 

 gations comparable to those of Shockman and Toennies 

 appear to be available for microorganisms other than bac- 

 teria. 



General Chemistry of Microbial Cell Walls 



Before discussing in any detail the nature of the chemical 

 constituents of microbial cell walls, let us first consider the 

 major classes of substances encountered in these structures. 

 It is generally agreed that nucleic acids are not major con- 

 stituents of walls, although, as Barkulis and Jones *^ have 



