96 



BACTERIA AS ANTAGONISTS 



a variety of other bacteria. The addition of top minnows (Gambusia) 

 to water polluted with E. colt caused the disappearance of the bacteria j 

 this was shown to be due to the inhibiting effect of the pyocyaneus or- 

 ganism present in the intestinal flora of Gambusia. The presence of this 

 antagonist in water renders the colon index of the water an unreliable 

 guide to pollution (388). When a mixture of the antagonist and the 

 colon organism was incubated, the former tended to outgrow the latter 

 after 24 hours. Even after sterilization, media in which Ps. aeruginosa 

 had grown depressed the growth of other microorganisms including 



TABLE 13. NONSPORE-FORMING BACTERIA AS ANTAGONISTS TO BACTERIA 



KNOWN PROPERTY 



Thermostable, filter- 

 able substance 



Depresses growth 



Thermostable, filter- 

 able substance 



Lytic action 



Colorless, thermo- 

 stable, lytic sub- 

 stance 



Alcohol-soluble 

 pigment 



Growth-inhibiting 



REFERENCES 



64, 78, 131,235, 



236, 298, 557 



451a, 798, 800, 

 801 



244, 303, 315, 334, 

 417, 418, 420, 421, 



446, 563, 566,692 



593 



51, 229,777 



420 



53,55, 132,368, 

 515,685,769,912, 



983 



3573,681 



no, 344,367,369, 

 457,485, 819,923 



244, 367, 369 



315,354,923, 

 936 



244, 462, 810, 923 



