140 



THE ACTIXOMYCKTES, Vol. II 



containing 0.5 per cent meat extract and 1 

 per cent glucose. The cell material was dried 

 and then hydrolyzed by acid or alkali. The 

 amino acid composition of this material, on 

 a percentage basis of the dry material, was 

 as follows: total nitrogen, 9.14; histidine, 

 0.84; arginine, 2.90; lysine, 2.13; leucine, 

 3.73; isoleucine, 1.49; valine, 3.40; methio- 

 nine, 0.55; threonine, 2.33; phenylalanine, 

 L.67; tryptophan, 0.62. 



In addition to the two forms of strepto- 

 mycin, S. griseus produces several other 

 antibiotics. Ether extracts from the myce- 

 lium of the organism yield a substance 

 designated as streptocin, which is active 

 against gram-posit ive bacteria but not 

 against gram-negative forms. Another anti- 

 biotic, designated as cycloheximide, can be 

 isolated by extracting the crude submerged 

 culture with chloroform, evaporating the 

 extract, and dissolving the residue in meth- 

 anol. Cycloheximide is not active againsl 

 bacteria but has strong antifungal prop- 

 erties; it is particularly active against yeasts. 



Varieties and Mutants 



The Griseus series represents a large' 

 widely distributed, and variable group of 

 organisms. It has long been recognized 

 (Waksman, 1959) that this series should be 

 divided into several species. The formation 

 of different antibiotics by the various specie- 

 offers an excellent supplementary basis for 

 such subdivision. The many cultures isolated 

 and studied in detail can thus be classified 

 into live distinct species. 



1. Streptomyces griseus Waksman and 

 Henrici. This comprises strains of *S. griseus 

 which produce streptomycin; they also pro- 

 duce cycloheximide. 



2. Streptomyces griseinus Waksman. 

 St rains of S. griseus which produce grisein or 

 grisein-like substances. These strains are as a 

 rule resistant to actinophage. Benedict and 

 Lindenfelser (1951) demonstrated that a 

 majority of streptomycin-producing strains 



of S. griseus form a green soluble pigment 

 in calcium malate medium and a yellow 

 pigment in calcium succinate medium; on 

 the other hand, the grisein-producing strains 

 of this organism do not form any green or 

 yellow pigments in these media, although 

 they show the typical greenish pigmentation 

 of the aerial mycelium. 



3. Streptomyces coelieolor (Muller) emend. 

 Kutzner and Waksman. This species com- 

 prises strains which produce the antifungal 

 agent candicidin but no antibacterial sub- 

 stance. The first organsim belonging to this 

 species was isolated by Muller (1908), and 

 designated Streptothrix coelieolor. It produced 

 a blue pigment similar to that formed by a 

 diphtheroid organism which he called Bacil- 

 lus coelieolor. The culture was a typical 

 Streptomyces and formed concentric rings in 

 its aerial mycelium. It developed well at 

 room temperature and at 36°C. It grew on 

 gelatin, with gradual liquefaction but with- 

 out pigmentation. On agar media containing 

 5 to 10 per cent dextrin, but not in glycerol 

 media, a brown pigment was formed. The 

 culture formed no aerial mycelium on ordi- 

 nary agar media, unless serum, glycogen, 

 dextrin, or starch was added. When glucose, 

 sucrose, arabinose, or other sugars were used, 

 no aerial mycelium was formed. 



Muller emphasized two important activ- 

 ities of S. coelieolor: It possessed antagonistic 

 properties, and it was active against Oiclium 

 lactis. Muller was thus one of the first to 

 demonstrate activities that were to make the 

 whole group of actinomycetes famous. Mul- 

 ler also studied the pigment extensively; he 

 called it amylocyanin; it is produced best on 

 potato media when grown at 30°C, but not 

 at 36°C. 



4. Streptomyces californicus Waksman and 

 Curtis. This species comprises strains which 

 produce viomycin, active against gram-posi- 

 tive bacteria only. Burkholder et al. (1955) 

 classified these organisms as strains of S. 

 griseus var. purpureas. Waksman (1958) 



