CULTURE MEDIA 17 



hydrates, a small amount of non-volatile acid, and about 50 

 milligrams of nitrogen in 100 cubic centimeters. For fermenta- 

 tion studies, add 1 to 2 per cent of the required carbohydrate. 

 For a sohd medium add 15 grams of agar. 



Medium 28 



Dried Yeast Infusion 



Yeast (dry, starch-free) 10.0 gm. 



Water 1,000.0 cc. 



Proceed as described under medium 27. 



Medium 29 



Dried Yeast-peptone Infusion 



Dried yeast 10. gm. 



Peptone 10.0 gm. 



Water 1,000.0 cc. 



Medium 30 



Ammonium Sulphate-glucose Solution 



Ammonium sulphate ((NH4)2S04) 5 .00 gm. 



Dipotassium phosphate (K2HPO4) .75 gm. 



Magnesium sulphate (MgS04-7H20) . 10 gm. 



Tartaric acid (C4H6O6) 1 .00 gm. 



Glucose 100.00 gm. 



Distilled water 1,000.00 cc. 



Medium 31 



Raisin Extract 



Raisins 375.0 gm. 



Ammonium chloride (NH4CI) 2.0 gm. 



Distilled water 1,000.0 cc. 



Allow the raisins to stand in 1 Uter of water at ice-box tem- 

 perature for 1 to 2 days. Mash, add the ammonium chloride, 

 cook in the steamer for 30 minutes, and filter. 



