CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



769 



Variants: Besson prepared a similar me- 

 dium as follows: 



(1) Mix 10.0 g. of potato starch in 180.0 

 g. of water and add 5.0 g. of pre- 

 cipitated chalk. 



(2) Distribute in flasks or petri dishes. 



(3) Sterilize at 115°C. 



References: Hefferan (1903-04 p. 520), 

 m (1920 p. 57). 



2385. Lloyd, Clark and McCrea's Gluten 

 Medium 



Constituents: 



1. Water. 



2. Gluten flour. 

 Preparation : 



(1) Mix tap water and gluten flour so 

 that a thick, but not sticky paste is 

 formed. 



(2) Place in petri dishes. 

 Sterilization: Autoclave for 20 minutes at 



115°C. 

 Use: Cultivation of Flugge's Mesentericus 



group. 

 Reference: Lloyd, Clark and McCrea 



(1920-21, p. 383). 



2386. Baginsky's Basal Starch Medium 



Constituents: 



1. Water 400.0 cc. 



2. Starch 20.0 g. 



Preparation : 



(1) Boil 20.0 g. sugar free amylum with 

 400.0 cc. water until a starch paste is 

 formed. 



(2) Distribute in 50.0 cc. lots in previ- 

 ously sterilized Erlenmeyer flasks. 



(3) Add one of the added nutrients. 

 Sterilization: Sterilize in flowing steam. 

 Use: To study fermentations. 



Added nutrients: The author added 1.0 g. 

 peptone or 10.0 cc. g. a solution of 1.0 g. 

 (NH4)2S04 and 1.0 g. or potassium phos- 

 phate in 100.0 cc. water to each flask. 



Reference: Baginsky (1888, p. 434-462). 



2387. Uschinsky's Asparaginate Starch 



Medium (Smith) 



Constituents : 



1. Water 1000.0 cc. 



2. Ammonium lactate 5.0 g. 



3. Sodium asparaginate 2.5 g. 



4. Na.SOi 2.5 g. 



5. NaCl 2.5 g. 



6. K2HPO4 2.5 g. 



7. CuCU 0.01 g. 



8. MgS04 0.01 g. 



9. Starch (potato) 

 Preparation : 



(1) Dissolve2, 3, 4, 5, 6, 7and8inl. 



(2) Dry potato starch. 



(3) Add 10.0 cc. of (1) to each test tube 

 containing 3.0 g. of (2). 



(4) Stir the mixture with a glass rod until 

 the starch has dissolved. 



(5) Place the tubes in a slanted position 

 at 75° to 85°C. for 20 minutes to 3 

 hours for 5 or 6 successive days. It 

 may be necessary to add 2.0 cc. dis- 

 tilled water to each tube to make up 

 for evaporation after the second 

 heating. The plugs must fit well. 



Sterilization : See step (5) above. 



Use: To study diastase action. Author 

 reported that other starches may be used 

 instead of potato starch. Sugars and high 

 alcohols may be added, 500 mg. per 10.0 

 cc. of medium. B. coli commune Ps. 

 hyacinthi, Sarcina aurantiaca and others 

 grew very well on this medium if sugars 

 were added. Smith also used the medium 

 to cultivate plant parasites. 



Variants : 



(a) Smith added 1.0 g. portions of starch 

 to each 10.0 cc. of medium instead of 

 3.0 g. The starch was prepared as 

 follows: 



(1) Scrub one-half bushel of large 

 smooth potatoes and dig out the 

 black spots. 



(2) Soak fbr 45 minutes in a 1:1000 

 mercuric chloride solution. 



(3) Sterilize the hands by thoroly 

 washing in the mercuric chloride 

 solution. 



(4) Rinse the tubers in sterile water, 

 pare deeply and run thru a grating 

 machine. 



(5) Throw into several liters of dis- 

 tilled water and work the pulp 

 thoroly with the hands to liberate 

 as much of the starch as possible. 



(6) Filter thru several layers of gauze. 



(7) Allow the starch to settle and 

 decant off the brownish fluid. 



(8) Stir up the sediment in a little 

 water and force the starch thru a 

 moderately meshed towel with 

 gentle rubbing. 



