Waksman — 20 — Actinomycetes 



defined, especially because of the frequent adaptation of anaerobes when freshly 

 isolated to an aerobic form of life upon continued cultivation. 



3. Proteolysis vs. non-proteolysis, such as gelatin liquefaction, milk coagulation 

 and proteolysis, serum and egg albumen proteolysis, properties that are quantitative 

 rather than qualitative in nature, with certain few exceptions. 



4. Amylolytic v. non-amylolytic action, sucrose inversion vs. non-inversion, 

 lipolysis, etc., properties that also cover phenomena which are largely adaptive in 

 nature but that are valuable as secondary characteristics. 



5. Thermophilic vs. mesophilic forms, a phenomenon which is also subject to 

 adaptation and which cannot be very sharply defined because of the many inter- 

 mediary types. 



6. Pigment production, one of the most significant properties. Both endopig- 

 ments and exopigments produced on svnthetic and on organic media are given con- 



FiG. 5 c Qsce p. 18). 



sideration. Because of this, a number of descriptions have hien based largely upon 

 this property, beginning with the early differentiation between chromogenesis 

 and non-chromogenesis on organic media. On synthetic media, many pigments are 

 produced which resulted in designation of many forms on the basis of the pigment, 

 M'hether present in the vegetative or in the aerial mycelium or whether it is dis- 

 solved in the medium. These pigments vary greatly in nature and intensity with 

 the composition of different media, as well as with conditions of growth and age 

 of the culture. Even with these limitations, however, pigment production is one of 

 the most important and most easily recognizable characteristics, especially when 

 media of known composition and definite conditions of culture are used. 



7. Serum diagnosis. This m.ay form a basis for more detailed differentiation of 

 specific types. Aoki (11) established that agglutination reactions can be carried 

 out with actinomycetes as readily as with bacteria; at first he found that the 

 anaerobic forms fall into one group and the aerobic forms into 5 other groups; later, 

 3 more groups were added establishing in all 9 types. The complement fixation 



