SOLUTION FOR NITEATE REDUCTION I07 



Medium 35 



Starch Nitrate Agar 



Agar 10 gm. 



Potassum nitrate (KNO3) i gm. 



Starch (CeHioOs)!! 5 gm. 



Bouillon 1000 c.c. 



After colonies develop, treat one series of plates with a 

 weak solution of potassium iodid (KI) in dilute HCl. The 

 treatment should result in the development of a character- 

 istic blue halo about the colonies that reduce nitrate to 

 nitrite. 



Hoffmann, C, Centbl. Bakt. (etc.), Abt. 2, Bd. 34, p. 386, 1912. 



Medium 36 

 Solution for Nitrate Reduction 



Dibasic potassium phosphate (K2HPO4) 0.5 gm. 



Potassium nitrate (KNO3) lo.o gm. 



Ethyl alcohol (C2H5OH) 5.0 c.c. 



Tap-water iooo.o c.c. 



Beijerinck, M. W., Centbl. Bakt. (etc.), Abt. 2, Bd. 25, p. 35, 19 10. 



Medium 37 

 Solution for Nitrate Reduction 



Dibasic potassium phosphate (K2HPO4) 0.5 gm. 



Potassium nitrate (KNO3) 2.5 gm. 



Filter-paper in strips 20.0 gm. 



Tap-water iooo.o c.c. 



Iterson, C. V., Centbl. Bakt. (etc.), Abt. 2, Bd. 11, p. 689, 1904. 



