CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



403 



L6hni3 and Moll's Asparagin Soil 

 Infusion Medium 1391 



Perotti's Dicyandiamid Soil In- 

 fusion Medium 1392 



Di. Organic nitrogen not added. 



Gutzeit's Mannitol Soil Infusion 

 Medium, 1393 



Jensen's Nitrate Soil Infusion 

 Medium 1394 



1377. Harrison and Barlow's Basal Wood 

 Ash Medium 



Constituents: 



1. Distilled water 1000.0 cc. 



2. Wood ashes 15.0 g. 



Preparation: 



(1) Add 15.0 g. wood ashes (maple wood, 

 mixed beech and maple, elm and 

 tamarack give good results) to 1000.0 

 cc. distilled water. 



(2) Heat in flowing steam, boil a minute 

 and filter. 



20 parts of maltose, sucrose or 

 dextrose (see table), maltose being 

 best. 



(4) Heat in flowing steam and boil a 

 moment over the flame or heat in 

 the autoclave for 20 minutes or 

 more at 10 pounds steam pressure. 

 This medium will vary faintly 

 alkaline to phenolphthalein to 

 alkaline -0.6 according to the 

 amount of ash used. 



(5) If desired acid potassium phosphate 

 may be added 2 to 5 parts per 1000 

 (see table) at any stage in the 

 preparation but best perhaps after 

 adding the sugar. 



(6) Sterilize in flowing steam or in the 

 autoclave at 10 pounds steam pres- 

 sure for 10 to 20 minutes. 



The accompanying table shows the 

 percentages of constituents used and 

 the reaction. 



Sterilization: Sterilize in flowing steam or 

 in the autoclave at 10 pounds steam 

 pressure for 10 to 20 minutes. 



Use: Cultivation of Pseudomonas radici- 

 cola and other nodule bacteria. 



Variants : 



(a) Harrison and Barlow added 1.0% 

 or 1.5% maltose to the medium as 

 prepared above. 



(b) Harrison and Barlow prepared media 

 as follows: 



(1) To 1000 parts cold water add 2.5 

 to 25 parts by weight (see table) 

 of wood ashes (maple, maple and 

 beech mixed, elm and tamarack 

 gave good results). 



(2) Shake well and filter at once or 

 after an hour or heat together to 

 boil, boil a minute and filter. The 

 filtrate should be almost colorless 

 and more alkaline as the amount of 

 ash and as the time before filtration 

 is increased. 



(3) To 1000.0 parts of filtrate add 5 to 



(c) Percival prepared the medium as 

 follows: 



(1) Add 8.0 g. of well burnt wood ashes 

 to 500.0 cc. distilled water and boil 

 for one minute. 



(2) Filter thru two sheets of paper. 



(3) Add 4.0 g. of maltose to 400.0 cc. 

 of the filtrate, and boil. 



(4) Tube and sterilize in the usual way, 

 method not given. 



(d) Giltner gavo the following method of 

 preparation of the medium: 



(1) Stir 5.0 g. of wood ashes (elm, 

 beech, maple) into 1000.0 cc. of 

 distilled water for 2 or 3 minutes 

 only. 



(2) Filter. 



(3) Add 1.0% commercial sucrose. 



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



(5) Strain while hot thru several thick- 

 nesses of clean cheese cloth. This 

 may be filtered if desired. 



(6) Sterilize by the Tyndall method in 

 the steamer. 



