160 



THE ACTINOMYCETES, Vol. I 



Table 35 

 Effect of lysozyme on actinomycete cells (Sohler, Romano and Nickerson) 



linked chitin being a constituent of the cell 

 wall. Free hexosamine was not released by 

 lysozyme to any appreciable degree by the 

 action of the enzyme. This was in contrast 

 to the action of lysozyme on gram-positive 

 bacteria, whereby N-acetylglucosamine is 

 released. Before hydrolysis, all the hexosa- 

 mine in the solution resulting from lysozyme 

 action was found in the undialysable frac- 

 tion. On the basis of these findings, it was 

 concluded that glucosamine exists in the cell 

 wall of S. fradiae as a polymer, which is not 

 associated with cell wall protein after the 

 action of lysozyme. 



It was suggested that these facts might be 

 of taxonomic use in distinguishing non- 

 sporulating strains of Streptomijccs from 



Nocardia and sporulating strains of Nocardia 

 from Streptomyces. A study of N. asteroides 

 3573, a sporulating strain which in culture 

 could easily be mistaken for a sti'epton\yces, 

 revealed that the carbohydrate composition 

 of the cell wall was that of a typical nocar- 

 dia, since both arabinose and^ galactose were 

 the principal sugars found. Similarly, S. 

 bobiliae 3310, a nonsporulating strain of 

 streptomyces that can be mistaken for a 

 nocardia, gave a cell wall composition that 

 was typical of a streptomyces. 



Considerable variation was found by Soh- 

 ler in the carbohydrate content of the cell 

 walls of microorganisms. The carbohydrate 

 content of most actinomycetes was about 20 

 per cent, on the basis of total reducing sugar. 



