CHEMISTRY OF CELL WALLS 29 



TABLE 9 

 Composition of the Walls of Several Gram-Positive Bacteria 



% Reducing % Amino 

 % N % P substances sugar 



Reference 13. 



M NaCl and water contained the four amino acids (alanine, 

 glutamic acid, glycine, and lysine) together with hexosamine 

 and glucose. 13 since then a great deal of qualitative and 

 quantitative work on walls has been performed by Cummins 

 and Harris,23.24 Work,^^ Snell, Radin, and Ikawa,-^ Ikawa 

 and Snell,26 Strange,^' Baddiley, Buchanan and Carss,-^ 

 Armstrong, Baddiley, Buchanan, Carss, and Greenberg,-^ 

 and Abrams,^^ and the following oustanding features have 

 firmly established some of the characteristic chemical prop- 

 erties of the walls: 



(a) Variety of principal amino acids limited to 3, 4, or 5. 



(b) Discovery of diaminopimelic acid in certain micro- 

 organisms and its localization in the wall. 



(c) The detection of D-isomers of amino acids. 



(d) The isolation and characterization of the amino sugar, 

 muramic acid, from spore peptides and walls. 



