170 



THE ACTINOMYCETES, Vol. I 



90 



o S. fradia* 



o S. gritaut 



N. polychromog«n«* 



N .rubra 



N. a«(«roid«> 



30 40 50 



TIME (MINUTES) 



60 



Figure 73. Lysis of cell walls of Streptomyces vs. Nocardia by lysozynie (Reproduced from: Romano 

 A. H. and Sohler, A. J. Bacteriol. 72: 866, 1956). 



at 30 or 37°C, lysis takes place in 4 to 6 

 hours. Not all the mycelium is lysed uni- 

 formly, some of the hyphae producing 

 chlamydospores, spherical bodies, or other 

 fragmentary material. Under favorable con- 

 ditions, these bodies are able to grow and 

 develop into fresh colonies. 



Katznelson isolated from manure com- 

 posts a culture of a thermophilic actinomy- 

 cete, whi(!h grew well on organic media. 

 When transferred to a synthetic medium con- 

 taining ammonium sulfate and starch, it un- 

 derwent lysis after 24 to 48 hours of incuba- 

 tion at 50°C. During growth, the culture 

 became acid. Addition of CaCOs to the cul- 

 ture prev(!ntod lysis. Stanier reported that an 

 agar-decomposing strain of S. coelicolor un- 

 derwent rapid autolysis and soon died out. 



Lysis took place when the organism entered 

 the sporulating stage. 



The process of autolysis in cultures of S. 

 griseus, the streptomycin-producing organ- 

 ism, has been studied extensively. When the 

 growth of this organism in submerged culture 

 reaches a maximum, lysis sets in and frag- 

 mentation of the mycelium occurs. The peak 

 of streptomycin production lags somewhat 

 behind the growth peak. The changes in re- 

 action of medium take place in two phases. 

 One occui;s during growth, when the medium 

 becomes acid, and one is associated with ly- 

 sis of the culture, when the medium becomes 

 alkaline and may reach a pH of 8.6. 



Dulaney et al. (1947) differentiated two 

 phases of metabolic activity of S. griseus, 

 grown inider shaken conditions: 



