Waksman — 2 — Actinomycetes 



certain factors, not the least among which is the confusion regarding 

 their morphology, life cycles, and systematic position; the frequently as- 

 sumed, although totally unjustified, difficulty of their cultivation and 

 identification; and the meagre knowledge of their biochemical activities. 



Numerous investigators have contributed much valuable information 

 as to the nature and activities of the actinomycetes. This makes possi- 

 ble the recognition of a definite system for characterizing and for classify- 

 ing these organisms. Information has also been accumulated concern- 

 ing their physiology and their importance in natural processes. One 

 particular property of these organisms, namely, their ability to produce 

 a varietv of antibiotic substances, has been utilized for a comprehensive 

 series of investigations in numerous institutional and industrial labora- 

 tories. This has resulted in the isolation of certain agents, which have 

 found application in combating a variety of bacterial infections in man 

 and in animals. 



Gradually it thus came to be recognized that the actinomycetes 

 are a large and heterogeneous group of microorganisms, comprising 

 several genera and many species. These organisms vary greatly in their 

 physiology and in their role in natural processes. Together with the 

 bacteria and fungi, they contribute to the cycle of life in nature, which 

 results in the liberation, from the complex plant and animal residues, 

 of a continuous stream of available elements, notably carbon and nitro- 

 gen, essential for fresh plant growth. 



