336 



CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



(6) Add 2 or 3 pieces of sterile iron 

 filings to sterile (5) under aseptic 

 conditions. 



Sterilization: Sterilize (5) in streaming 

 steam for 6 hours. Sterilize 2 or 3 pieces 

 of iron filings dry heat at 150° for one 

 hour. 



Use: Cultivation of Ferribacterium duplex. 

 Author reported that after 5 or 10 days a 

 slight yellow membrane was formed. 



Reference: Brussoff (1916 p. 549). 



1154. Schmidt's Hydrolyzed Peat Solution 



Constituents : 



1. Water 1000.0 cc. 



2. Peat 20.0 g. 



3. Salts. 

 Preparation : 



(1) Add 1000.0 g. of 0.3% HCl to 20.0 g. 

 of peat and hydrolyze for 1 hour at 

 2.5 atmospheres pressure. 



(2) Filter. 



(3) Neutralize and add an excess of 

 CaCOs. 



(4) Add the usual salts (amounts or kinds 

 not given). The salts are to be nitro- 

 gen free. 



Sterilization: Not specified. 



Use: To study nitrogen assimilation by 

 soil forms. Author reported that azoto- 

 bacter formed as a scum on the surface of 

 the medium in several days. 



Reference: Schmidt (1920 p. 283). 



1155. Schmidt's Peat Solution 



Constituents : 



1. Water 1000.0 cc. 



2. NH4CI (0.25%) 2.5 g. 



3. K2HPO4 (0.05%) 0.5 g. 



4. CaCOs (2.0%) 20.0 g. 



5. Peat 20.0 g. 



Preparation : 



(1) Dissolve 2, 3 and 4 in 1. 



(2) Add 20.0 g. of peat to (1). 

 Sterilization: Not specified. 



Use: Cultivation of soil and horse manure 

 forms. Azotobacter. Author reported 

 that azotobacter formed a membrane on 

 the surface after several days. 



Variants: The author used moss instead of 

 peat. 



Reference: Schmidt (1920 p. 284). 



1156. Buchanan's Basal Legume Extract 

 Solution 



Constituents: 



1. Water 1000.0 cc. 



2. Legume extract (Park Davis & Co.). 

 Preparation : 



(1) Boil 1000.0 cc. of one of Park Davis & 

 Company's standard legume fluid ex- 

 tract until all the alcohol has evapo- 

 rated. The legume extracts used 

 were those of clover, tolu, catechu, 

 physostigma, red clover blossom, 

 glycyrrhiza, kino, baptisia, senna and 

 scoparius. 



(2) Make up to 1000.0 cc. by the addition 

 of water. 



(3) Filter. 



(4) Prepare 10.0, 5.0, 1.0 and 0.1% solu- 

 tions of these extracts with water. 

 In case of the clover extract, do not 

 dilute. In case of the glycyrrhiza 

 prepare only 1.0 and 0.1% solutions. 



(5) Add one of the added nutrients to 

 extract solutions. 



Sterilization: Sterilize for 20 minutes on 

 each of 3 successive days in streaming 

 steam. 



Use: To study gum formation by Bacillus 

 radicicola. The author reported that 

 the extract of catechu, physostigma, kino 

 and scoparius inhibited growth. The 

 remaining legume extracts favored growth 

 and gum production. 



Added nutrients: The author added 2.0% 

 sucrose or 1.0% maltose to the extracts 

 prepared as indicated in step (4) above. 



Reference: Buchanan (1909 p. 391). 



1157. Buchanan's Salt Legume Extract 

 Solution 



Constituents : 



1. Water 1000.0 cc. 



2. Legume extract (Park Davis & Co.). 

 Preparation : 



(1) Boil 1000.0 cc. of one of Park Davis & 

 Company's standard legume fluid 

 extract until all the alcohol has 

 evaporated. The legume extracts 

 used were those of clover, tolu, ca- 

 techu, physostigma, red clover blos- 

 som, glycyrrhiza, kino, baptisia, 

 senna and scoparius. 



