Chapter VII — 11^ — Antagonistic Properties 



that were antagonistic to the Ftisariuni when grown in their own soil- 

 infusion agar were not always antagonistic when tested in soil-infusion 

 agar prepared from other soils. A culture of an actinomyces isolated 

 from a compost produces lysis of Fusarknn. When spores of both or- 

 ganisms were mixed in an agar medium, the fungus at first developed 



Fig. 24.— Method of measuring antibacterial or antifungal potency of an 

 antibiotic, by the agar streak method Qrom Reilly, Schatz and Waksman, 

 356). 



normally, but began to undergo lysis on the fifth day, large sections 

 of the mycelium disappearing. On the seventh day, only chlamydo- 

 spores were observed. After 9 days, the fungus completely disappeared, 

 whereas the actinomyces made a normal growth. The antibiotic active 

 against the Fusarimn was later designated as musarin. It was 

 found to be an optically active acid, of the probable composition of 

 CC35HgoOi4N2)t2, and had an activity of 1:80,000 to 1:100,000 (12). 



