Chapter V — 95 — Metabolism 



scab formation, Afanasiev questioned these reports, since the cuhures 

 did not cause scab under controlled conditions. 



The pigment produced by S. coelicolor was first studied by Muller 

 in 1908 (306). This pigment is dark blue and diffuses readily into 

 the medium. If the reaction is acid the pigment becomes red; when 

 the reaction of the medium is alkaline, the pigment is blue. Muller 

 observed that this pigment was produced on synthetic media only with 

 starch as a source of carbon. Waksman, however, demonstrated that 

 this pigment or allied pigments are also produced with sucrose and 

 other carbon sources. Chemically, the blue pigment was at first said 

 (240) to belong to the anthocyanins. This was not confirmed, how- 

 ever, (116). In 1914, Beijerinck (26) described, under the name 

 A. cyaneiis, a culture which would now be classified with the Nocardia 

 group and which produced a pigment similar in its properties to the an- 

 thocyanins. This pigment was recently designated as litinocidin and 

 was found to possess antibiotic properties (133). 



Lieske distinguished two groups of pigments produced by actino- 

 mycetes: (a) the chromophores or pigment which is not excreted from 

 the mycelium into the medium, and (I?) the chromopars or pigment 

 which is readily excreted. The first group comprises various pigments 

 produced in the vegetative mvcclium grown on synthetic media, namely, 

 vellow, orange, red, blue, violet, brown, black, and green; the aerial 

 mvcelium of these cultures may be white, rose, lavender, red, yellow, 

 orange, green, or grey. The soluble pigments are usually yellow, blue, 

 and red; occasionally they are green; and some orange and brown pig- 

 ments are also produced. 



Kriss (240) could not accept Lieske's separation of actinomyces 

 pigments into the above types or the classification of Duch^ into endo- 

 pigments and exopigments. Even in the case of the chromophore pig- 

 ments, part at least of the pigmented material is dissolved in the me- 

 dium, possibly because of lysis of some of the cells. The solubility of 

 the chromopar pigments in water is due to the greater penetration of 

 the pigment through the cell wall. The chromophore pigments are 

 either insoluble in water and are bound to the proteins or are dissolved 

 in the fats and lipoids of the cell, or they are water-soluble but unable 

 to pass through the living cell plasma; on the death of the cell, the pig- 

 ment may be able to dissolve into the medium. 



Kriss recognized four types of pigments among the actinomycetes: 



A. Pigments soluble in water and in 96 per cent alcohol. These 

 pigments are capable of passing through the living cell plasma. They 

 have been subdivided into, (fi) anthocyanins, soluble only in water, 

 and (I?) hydroactinochromes, soluble in water and in alcohol. 



B. Lipoactinochromes, insoluble in water but soluble in alcohol 

 and in other organic solvents. 



J C. Pigments insoluble in water and in organic solvents. 

 D. A combination of water-soluble and water-insoluble pigments. 



