THE ACTINOMYCETES, Vol. I 



Figure 2. Growth of an actinomycete in animal tissue (Reproduced from: Butterfield, E. E. J. In 

 fectious Diseases 2: 430, 1905). 



et al.), and the importance of actinomycetes 

 in natiu'al pr-ocesses were given ever-growing 

 consideration. 



4. The biochemical or, more preciselij, the 

 antibiotic period. A new era in the study of 

 actinomycetes })egan about 1940. Then, it 

 was estabhshed that a large number of these 

 organisms are capable of producing a great 

 variety of chemical substances that have the 

 capacity to inhibit the growth of various 

 microorganisms, and that some of these 

 substances can find chemotherapeutic appli- 

 cations in the treatment of numerous infec- 

 tious diseases of man, animals, and plants. 



This resulted in extensive investigations de- 

 voted to the nutrition of actinomycetes, the 

 biosynthesis by them of various chemical 

 compounds, their chemical structure, life 

 cycle, and numerous biochemical activities. 



1. Actinomfjcetes as Caumtive Agents 

 of Disease {1873-1900} 



The initial work on the actinomycetes was 

 done by two eminent botanists, F. Cohn in 

 1874 and C. 0. Harz in 1877. Unfortunately, 

 two circumstances soon shifted the interest 

 in these organisms from the botanists to 

 clinicians and veterinarians. 



