AN'rAcoMS'i'ic iM{()iM:i{'rii:s 



213 



Tablk 52 Tahi.k ot 



Sid-rcjis of antayoitistic arliiiiniiiicilcs iKolulcil from Dishihulion, of nntibiolic (icliviti) of actinonij/cetes 

 soils and other naliiral siihstrata (Boiu'dict ) arcordhuj to ycnus (Kniersoii et al.) 



Table 53 



Distribution of antagonistic properties avionii 

 actinomycetes* (Johnstone) 



Zone of 



inhibition, 



mm 



Per cent of cultures active against 

 B. subtilis E. coli J/, avium M. phlei 



Nutrient agar 



Glucose asparagine agar 



* Cross-streak method used. 



temperatures. Kriss also believed that the 

 agent was similar to egg-white lysozyme. 



Waksman et al. made a detailed sur- 

 vey of actinomycetes possessmg antago- 

 nistic properties (Waksman, 1937, 1941, 

 1945). This led directly to the isolation of 

 the first antibiotic produced by a member of 



Genus 



this group of organisms, namely, actinomy- 

 cin. Antibiotic-producing actinomycetes 

 were found to be widely distributed in na- 

 ture, especially in soils and in composts. Two 

 hundred and forty-four cultiu'es were iso- 

 lated and tested. Of these, 106 or 43.4 per 

 cent, possessed some antagonistic properties, 

 and 49, or 20 per cent, were highly antago- 

 nistic (Table 51). An examination of a large 

 series of well-identified cultures of actino- 

 mycetes kept for a number of j^ears in a 

 type culture collection showed similar rela- 

 tions (Welsch). The antagonistic forms were 

 found to belong largely in the genus Strepto- 

 myces. 



Burkholder isolated 7,369 cultures of ac- 

 tinomycetes from soil. Of these; l,8(i9 inhib- 

 ited growth of Staph, aureus, 261 inhibited E. 

 coll, and 514 showed an antagonistic effect 

 against C. albicans. 



With the growing interest in antibiotics 

 throughout the world, numerous other sur- 

 veys have since been made, as summarized 

 by Benedict (Table 52). Alost of these re- 



