CHARACTERIZATION OF STREPTOMYCES SPECIES 71 



and protein derivatives, notably the ami luced in tyrosine (or protein containing 



acid tyrosine, is an important species charac- tyrosine) media. The tyrosinase reaction 



teristic. Certain species may produce only was, therefore, considered to be the proper 



faint brown soluble pigments on organic one. 



media, as well as on synthetic media. Differ- Shinobu t L958) attached greal importance 



ent cultures, especially on continued cultiva- to the "tyrosinase reaction" in the species 



ion on artificial media, will show greal characterization of Streptomyces. Ettlinger 



variation in pigmenl production. et al. (1958) also recognized the difference 



Since about one third of all species of between melanin formation and the tyrosi- 



Streptomyces now recognized are melanin- nase reaction. In line with the idea- of 



positive (Waksman, 101!); Skinner, L938), Beijerinck, Waksman, and Ettlinger et al., 



and since this property has been utilized ex- recognition will be given here to melanin 



tensively in the classification of actinomy- formation rather than to the tyrosinase re- 



cetes, a knowledge of this reaction is of greal action. 



importance. Gasperini (1891) first utilized The formation of yellow, red, blue, green, 



this property in dividing the aerobic A ctino- and other soluble pigments is also highly 



/////rev into .1. chromogenus and .1. albus. It characteristic of the species growing on syn- 



was later recognized, however, that melanin thetic media. There is considerable variation 



production is characteristic of a large number in the intensity of these pigments, depending 



of species, including such important forms upon the strain of organism. In view of the 



as the plant pathogen S. scabies. fact that color standards are not always 



Beijerinck (1900, 1011, L913) designated available, Lindenbein (1952) suggested a 

 as "melanin" the dark pigment produced by series of color designations which are simple 

 .1. chromogenus from peptone, although this and convenient. This system in a modified 

 organism did not always produce the pig- form is given in Appendix I. 

 ment from tyrosine. He considered the pig- Pigment formation is considered by Kras- 

 ment as a catabolic product of the organic silnikov (lOOO) as a constanl specific prop- 

 nitrogen, erty, although the nature of the pigments 



Lehmann and Sano (1008) first suggested varies with the composition of the medium, 



the expression "tyrosinase reaction." They The color of t he aerial mycelium is not con- 



used for their studies a tyrosine-containing sidered as constant and is greatly influenced 



medium, melanin being known to be an oxi- by the composite f the medium (see also 



dation product of tyrosine. Waksman (1916, Conn and Conn, L941). 

 L919, L920) expressed considerable doubt The variability in pigmentation of differ- 

 that the production of a soluble dark pig- ent strains of S. aureofaciens was studied in 

 ment on beef-peptone agar is due solely to detail by Duggar <t al. (1954) and Backus 

 this reaction. Gelatin, containing no tyro- <lul. (1954), and is illustrated in Table 7. 

 -inc. gives the characteristic pigmentation. 



Some species producing a typical dark pig- utilization of carbon soi ia es 



ment on the beef-peptone agar may fail to The ability of different species of actino- 



do so on synthetic media containing tyrosine, mycetes to utilize as sources of carbon and 



Skinner (1938) recognized a difference be- energy various organic substances, such as 



tween the dark pigmenl produced in peptone carbohydrates, alcohols, salts of organic 



media and not in lyrosine-cont aining syn- acids, fats, and amino compounds, can be of 



thetic media and the black pigment pro- considerable diagnostic value. These studies 



