764 



CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



Preparation : 



(1) Heat 1000.0 g. of good rich garden soil 

 with a liter of tap water for 30 minutes 

 in the autoclave under pressure of 1 

 atmosphere or boil with 2 liters of 

 water over a free flame. 



(2) Pour off the turbid liquid. 



(3) Mix talc with the liquid. 



(4) Filter thru a double filter paper. 



(5) Make up the volume to 800.0 cc. if 

 necessary. 



(6) Dissolve 3, 4, 5, 6 and 7 in (5), 



(7) Tube. The reaction must be dis- 

 tinctly alkaline. 



Sterilization: Not specified. 

 Use: Cultivation of cyanamide decom- 

 posers. 

 Reference: Lohnis (1913 p. 108). 



2371. Conn's Tartrate Soil Infusion Gelatin 

 Constituents : 

 1. Water 1000.0 cc. 



2. Gelatin (12.0%) 120.0 g. 



3. Soil infusion (20.0%) 200.0 cc. 



4. Glucose (0.1%) 1.0 g. 



5. Ammonium tartrate (0.1%). 1.0 g. 

 Preparation : 



(1) Prepare soil infusion by heating soil 

 for one hour at one atmosphere pres- 

 sure, mix with twice its weight of 

 water, allow to stand over night cold, 

 boil 30 minutes and filter. Dilute, 

 to contain 0.12 to 0.14% total solids, 

 if necessary. 



(2) Dissolve 12.0% gelatin, 20.0% soil 

 infusion, 0.1% glucose and 0.1% 

 ammonium tartrate in water. 



(3) Add NaOH to adjust the reaction to 

 +0.5 to phenolphthalein. 



Sterilization: Not specified. 

 Use: Bacterial count in soil. 

 Reference: Conn (1910 p. 425). 



