Chapter VII 



Ill- 



Antagonistic Properties 



Waksman ct al. (468) came to the conclusion that actinomycetes 

 possessing antagonistic properties against bacteria and fungi are widely 

 distributed in nature, especially in soils and in composts. Two hundred 

 and forty-four cultures were isolated at random from different soils. 

 Of these, 106 cultures or 43.4 per cent possessed some antagonistic 

 properties, and 49 cultures or 20 per cent were highly antagonistic. 

 Similar relations were observed in examining a large series of well- 

 identified organisms kept for a number of years in a type culture col- 



FiG. 23 b.— No inhibition ot stu I'lnnncin-sensitive or of streptomycin- 

 resistant strains Cfroni Williston ct al., 510). 



lection (503). The antagonistic forms were most abundantly repre- 

 sented by the genus Strepoviyces (Table 21). 



BuRKHOLDER (56) examined the antagonistic properties of 7,369 

 cultures of actinomycetes isolated from soil, using various test organisms, 

 namely gram-positive and gram-negative bacteria, acid-fast bacteria, 

 fungi including yeasts and green algae. Of these cultures, 1,869 in- 

 hibited S. mireiis in agar streak plate tests, 261 inhibited E. coli, and 

 514 showed an antagonistic effect against Candida albicans. 



J Various other surveys have been conducted dealing with the capacity 

 of large numbers of actinomycetes to inhibit the growth of bacteria as 



