Waksman — 96 — Actinomycetes 



Only a few of the pigments produced by actinomycetes have been 

 studied from a chemical viewpoint. 



Krainsky (230) examined in detail several actinomyces pigments. 

 S. erythrochromogenus produced a red pigment soluble in water but not 

 in alcohol, ether, or chloroform. The addition of alcohol to an aqueous 

 solution of the pigment brought about its precipitation. Acids and alka- 

 lies had no effect upon it. A yellow pigment was isolated from S. cel- 

 hdosae. It became violet-red in an alkali solution and blue-green in 

 concentrated H2SO4 . This, as well as the red pigment, was considered 

 to be a carotin. The green pigment of S. viridochromogeniis was found 

 to change to red on treatment with concentrated H2SO4 . 



Waksman demonstrated that the pigment produced by S. violacetis- 

 niher behaved as an indicator, being red in an acid and blue in an 

 alkali; the change in pigmentation took place at pH 6.6 (443). Conn 

 (78) concluded that the two blue pigments produced by two species 

 of Streftomyces, S. coelicolor and S. violacens-rnher, are not identical. 

 The pigment produced by the first is similar but not identical to azo- 

 litmin. On the basis of this differentiation, Conn believed that the 

 two organisms represent distinct species. This concept could not be 

 accepted by Oxford (330), since the pigment contained too little nitro- 

 gen; neither could its phenazine (116) or anthocyanidin nature be ac- 

 cepted. 



LiESKE studied a carmine-red pigment that became, on boiling in 

 dilute acid, soluble in alcohol and in ether. The brick-red pigment of 

 other strains of actinomycetes becomes soluble only under the action 

 of concentrated HCl; on treatment with H2SO4 it is changed to a 

 blue-green pigment. N. folychroiuogenes produces a red pigment, sol- 

 uble in chloroform, ether, and acid, but not in alcohol, glycerol, water, 

 or dilute alkali; this pigment is also changed to blue-green by H2SO4 . 

 A light yellow pigment produced by certain actinomyces species was 

 found to be insoluble in organic solvents, but soluble in dilute KOH 

 solution; it changed, on treatment with concentrated H2SO4, first to 

 green, then to dark brown. According to Lieske, the green, brown, 

 and violet pigments of the chromophor type are insoluble in common 

 solvents and give a sepia-brown color when treated with concentrated 

 H2SO4. The yellow-red pigment of N. corrallinn was later identified 

 (354) as belonging to the lipochrome group of fat-soluble pigments. 



Pigment formation by actinomycetes is influenced by the reaction 

 of the medium, aeration, temperature and by the carbon and nitrogen 

 sources, as shown previously in Tarle II. According to Kriss, the 

 composition of the medium has a quantitative rather than a qualitative 

 effect upon pigment production. He measured the adsorption spec- 

 trum of the pigment obtained by extraction with ether and alcohol 

 from S. longis'porus ruber. Although several pigments were thus recog- 

 nized, they were apparently related. The blue pigments of S. coeli- 



