I20 SOIL BACTERIOLOGY 



Medium 67 



Raisin Extract 



Raisins 375 gm. 



Ammonium chlorid (NH4CI) 2 gm. 



Distilled water 1000 c.c. 



Allow the raisins to stand in i liter of water for one to two 

 days. Mash, add the ammonium chlorid, cook in the 

 steamer for thirty minutes, and filter. 



Medium 68 



Solution of Yeast-water 



Yeast cells 250 gm. 



Distilled water 1000 c.c. 



Take 250 grams of pressed yeast or 500 c.c. of washed 

 yeast; steam in i liter of water for one hour. Filter while 

 warm and steam again for thirty minutes. Make the 

 reaction neutral to phenolphthalein, filter, and sterilize in 

 the steamer for three successive days. 



Dextrose-yeast-water may be prepared by dissolving 

 10 per cent, of dextrose in the yeast-water. 



PUNGI 



Medium 69 

 Solution for Fungi 



Ammonium nitrate (NH4NO3) lo.o gm. 



Dibasic potassium phosphate (K2HPO4) 5.0 gm. 



Magnesium sulphate (MgS04 + 7H2O) 2.5 gm. 



Ferrous chlorid (FeClg + aq.) trace 



Saccharose (C12H22O11) 50.0 gm. 



Distilled water looo.o c.c. 



