116 



THE ACTINOMYCETES, Vol. I 



Table 19 



Metabolic changes characterizing the two phases during the submerged growth of 

 S. griseus (Dulaney and Perlman) 



Phase I 



Phase II 



Streptomycin 

 pH 



Mycelium 

 Glucose 

 Soluble carbon 



Lactic acid 

 Oxygen demand 

 Soluble nitrogen 

 Inorganic phosphorus 



Slight production 

 Gradual rise 

 Rapid growth 

 Rapid utilization 

 Gradual utilization 



Slow production and utilization 



Maximum 



Used extensively 



Used at maximum rate 



Maximum rate of production 



Reaches maximum 



Gradual autolysis 



Small remaining amount exhausted 



Concentration reaches maximum 



and remains constant 

 Slow utilization 

 Decreases to minimum 

 Concentration increases 

 Released into medium 



the culture increasevS, pointing to the pref- 

 erential utilization of the proteins as a source 

 of energy. With the advance in growth, 

 sugar utilization and ammonia consumption 

 proceed at a rapid rate, parallel to the in- 

 crease in dry weight of the organism. 



Dulaney and Perlman divided the meta- 

 bolic processes of actinomycetes into two 

 phases, crescense and senescence. In the 

 first phase, there was uptake of soluble 

 nitrogen, carbon, and phosphate into the 

 mycelium ; the oxygen demand was high and 

 the utilization of glucose was rapid, but 

 there was very little antibiotic production. 

 In the second phase, mycelial weight de- 

 clined, phosphate and nitrogen were ex- 

 creted into the medium, oxygen demand 

 fell, and streptomycin was produced. Some 



6 8 



TIME', DAYS 



Figure 55. Metabolism of *S. griseus (Repro- 

 produced from: Cochrane, V. W. and Dimmick, I. 

 J. Bacteriol. .58: 727, 1949). 



lactate also formed during the early stages, 

 but this disappeared rapidly (Table 19). 



Van Dyck and DeSomer also recognized 

 two stages in the growth of a streptomyces 

 (S. aureofaciens) . The first stage is char- 

 acterized by cell synthesis and nutrient up- 

 take. The second stage is characterized by a 

 slower increase in cell synthesis ; protein and 

 ribonucleic acid decrease, and desoxja-ibo- 

 nucleic acid changes but slightly; the de- 

 crease in nucleoprotein cannot be ascribed to 

 lysis, since it is not accompanied by a de- 

 crease in weight of mycelium or by an in- 

 crease in the nitrogen in the medium. 



The course of metabolism of S. venezudae 

 has been studied by Gottlieb and Legator 

 (1953). The course of growth and the meta- 

 bolic processes of an actinomycin-producing 

 strain of *S. chrysomallus were reported by 

 Dietzel et al. (1950). Schmidt - Kastner 

 found, for example, that the addition of DIj- 

 isoleucine and sarcosine resulted in certain 

 new actinomycins differing in their peptide 

 chains. The metabolic processes of neo- 

 mycin-producing S. fradiae were examined 

 by Giolitti and LugU (1956). 



Numerous other metabolic processes of 

 actinomycetes, notably of members of the 

 gxnuis Streptomyces, have been described. 

 Sekizawa (1958), for example, found that a 

 culture of Streptomyces produces ethoxy- 

 cthene-1,2 dicarboamide, as represented by 



