figure: i 



113 



Pw Cent o 



Acidify of media used 



01 o.z d.» o'-v o's tie 



/Yo asp. agar 

 dot I and NH<N0 3 

 Ammonium nitrate- 

 Ammonium nitrate and starch 

 Ltptnan and Brown agar 

 Soil extract (unheated) 

 Soil extract (autoclaveol) 

 Wheat &tra*/ extract 

 Leat extract 

 \S torch- 

 Agar a Zona 

 Agar and soil 



5084—8 



