CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



709 



distilled water for two or three 

 minutes only. 



(2) Filter. 



(3) Add 1.0% washed agar. 



(4) Heat in steam for 30 minutes. 



(5) Add 1.0% commercial sucrose. 



(6) Boil for 5 minutes over a free flame. 



(7) Strain while hot thru several thick- 

 nesses of clean cheese cloth. This 

 may be filtered if desired. 



(8) Sterilize by the Tyndall method in 

 the steamer. 



References : Harrison and Barlow (1907 p. 

 269), Lohnis (1913 p. 113), Harvey (1921- 

 22 p. Ill), Percival (1920 p. 204), Giltner 

 (1921 p. 377). 



2194. Fremlin's Soil Infusion Agar 



Constituents: 



1. Soil infusion 1000.0 cc. 



2. Agar 

 Preparation : 



(1) Solidify soil infusion with agar. 



Sterilization: Not specified. 



Use: Cultivation of nitroso bacteria. 

 Francois-Perey cultivated soil protozoa 

 on a similarly prepared medium 



Variants : 



(a) Lohnis prepared the medium as 

 follows: 



(1) Heat 1000.0 cc. 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) Solidify with agar. 



(7) Sterilize (method not given). 



(b) Francois-Perey prepared the medium 

 as follows: 



(1) Boil 1000.0 g. soil with 2000.0 cc. of 

 water. 



(2) Filter and dissolve 2.0% agar in 

 the filtrate. 



References: Fremlin (1903 p. 373), Lohnis 

 (1913 p. 101), Giltner (1921 p. 370), 

 Francois-Perey (1925 p. 315), taken from 

 (1925 p. 93). 



2195. Gowda's Soil Infusion Agar 



Constituents: 



1. Water 2000.0 cc. 



2. Soil 1000.0 g. 



3. K0HPO4 1.5 g. 



4. (XH4)2S04 1.5 g. 



5. MgS04 0.75 g. 



6. reoS04 0.02 g. 



7. NaCl 3.0 g. 



8. Na.COs 1.0 g. 



9. Agar 

 Preparation : 



(1) Digest 1000.0 g. soil in the autoclave 

 for 2 hours with 2 liters of water. 



(2) Soak agar in water for 8 to 10 days. 



(3) Dissolve 3 in 100.0 g. conductivity 

 water. 



(4) Dissolve 4, 5 and 6 in 100.0 g. con- 

 ductivity water. 



(5) Dissolve 7 and 8 in 100.0 g. con- 

 ductivity water. 



(6) Add 1.0 cc. each of sterile (3), (4) and 

 (5) to each agar plate. The details 

 of preparation of the plates are not 

 given, or the amount of soil extract 

 that is to be added to the plate, or if 

 the washed agar is to be dissolved in 

 the soil extract is not stated. 



Sterilization: Pass the liquid from (1) thru 

 a Chamberland filter, then sterilize on 3 

 successive days in the autoclave under 15 

 pounds pressure for four hours. Sterilize 

 (3), (4) and (5) separately, method not 

 given. 



Use: To study nitrification. Gowda re- 

 ported that the ammonia was oxidized to 

 nitrites. 



Reference: Gowda (1924 p. 255). 



2196. Conn's Soil Infusion Agar 



Constituents: 



1. Water 900.0 cc. 



2. Soil infusion 100.0 cc. 



3. Glucose 1-0 g. 



4. Agar 15.0 g. 



Preparation : 



(1) Preparation of soil infusion not given. 



(2) Dissolve 3 and 4 in 1. 



(3) Mix (1) and (2). 

 Sterilization: Not specified. 

 Use: Cultivation of soil bacteria. 



