128 



THE ACTINOMYCETES, Vol. I 



J^ACTIC 



STREPTOLIN 



14 



12 



30 50 



HOURS 



Figure 60. Metabolic changes produced by a 

 streptolin-forming streptomyces. Streptolin, units 

 10^ ml ; glucose, mg/ml ; lactic acid, mg/ml (Repro- 

 duced by special permission from: Rivett, R. W. 

 and Peterson, W. H. J. Am. Chem. Soc. 69: 3007, 

 1947). 



DL-threonine ; best production of neomycin, 

 with alpha-alanine, L- and DL-aspartic 

 acids, L- and D-ghitamic acids, L-histidine, 

 L-proline, DL-threonine, and N-Z amine. 



Some actinomycetes, notably nocardias, 

 attack proteins to a rather hmited degree. 

 Casein may not be hydrolyzed. Even gelatin, 

 which is readily used by the great majority 

 of streptomyces, is attacked by only some 

 nocardias, and frequently not ^-ery readity. 

 In general, nocardias are unable to utilize 

 xanthine, tyrosine, and certain other amino 

 acids. The presence of glucose does not have 

 the same depressing effect upon the decom- 



position of amino acids by actinomycetes, 

 as shown by the amount of ammonia lib- 

 erated, as it does upon fungi (Waksman and 

 Lomanitz) . 



A study has been made of the ratio of 

 carbon to nitrogen consumption by S. 

 lavendulae. This was found to depend upon 

 conditions of growth, nature of organism, 

 and age of culture. With sugar and tryptone 

 in the medium, the ratios increased to about 

 300 per cent as growth advanced, resulting 

 in greater oxidation of the carbohydrate as 

 compared to the utilization of the nitrogen 

 in tryptone for cell synthesis. This was true 

 especially for submerged cultures : the abun- 

 dance of available oxygen brought about a 

 greater oxidation of carbohydrate as com- 

 pared to the tryptone consumed (Woodruff 

 and Foster). 



Romano and Nickerson (1958) studied the 

 utilization of amino acids as sole sources of 

 carbon and nitrogen by S. fradiae. Alanine, 

 histidine, lysine, glutamic acid, proline, and 

 arginine supported growth; aspartic acid, 

 threonine, leucine, isoleucine, and methio- 

 nine did not. A coenzyme I-linked glutamic 

 dehydrogenase was found in a cell free ex- 

 tract of the organism. It was suggested that 

 this was the mechanism by which members 

 of the glutamic acid series are utilized via 

 the tricarboxylic acid cycle. 



Certain actinomycetes, when growing in a 

 peptone medium without any carbon 

 sources, are able to produce urea (Guitton- 

 neau). Out of 477 cultures of streptomyces 

 isolated by Stapp, 177 were able to use urea 

 readily as a source of nitrogen. Some of the 

 cultures used as soiu'ces of nitrogen, xanthine, 

 hypoxanthine, and adenine, in concentrations 

 of 0.05 to 0.1 per cent. A large number also 

 used uric acid, but not uracil, p^a-idine, 

 imidazol, and pyrrhol. 



According to Moore ( 1 949) , certain species 

 of Nncardia are able to utilize pyridine, 

 aniline, nicotinic acid, and nitrobenzene as a 

 source of nitrogen, and phenol plus am- 



