CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



677 



(4) Steam until the precipitate turns 

 white. 



(5) Dilute about one-third with distilled 

 water and steam 5 more minutes. 



(6) Decant the solution and filter, keep- 

 ing most of the precipitate in the 

 beaker until most of the liquid has 

 passed thru the filter. 



(7) Wash the precipitate with a little 

 distilled water. The filtrate is 

 cloudy. 



(8) Make up to 250.0 cc. by the addition 

 of distilled water. 



(9) Steam 10.0 g. yeast in 100.0 cc. 

 distilled water for 45 minutes in an 

 Arnold. Filter until filtrate is clear 

 and brilliant. 



(10) Wash with 100.0 cc. distilled water. 



(11) Make up to 250.0 cc. with distilled 

 water. 



(12) Place 30.0 g. agar in 2000.0 cc. 

 distilled water and let stand for 24 

 hours. 



(13) Pour off the water and add an equal 

 volume of fresh water. 



(14) Allow to stand for 24 hours, pour on 

 cotton flannel cloth in a funnel and 

 wash with a liter of distilled water. 

 Press out as much water as possible. 



(15) Add enough water to have the total 

 weight 1030.0 g. 



(16) Dissolve the agar by heating in the 

 Arnold, and filter thru cotton flannel 

 until clear. 



(17) Mix equal parts of (16) and (8). 



(18) The usual pH = 6.7. 

 Sterilization: Method not specified. 

 Use: To determine the bacterial count of 



milk. 

 Variants: Any desired indicator may be 



added. 

 Reference: Ayers and Mudge (1920 p. 581). 



2087. Park, Williams and Krumwiede's 

 Basic Beer Wort Agar 



Constituents : 



1. Beer Wort 1000.0 cc. 



2. Agar (1.5%) 15.0 g. 



Preparation: 



(1) Dissolve 2.0% of any of the added 

 nutrients in beer wort (see medium 

 1218) that has been solidified by the 

 addition of 1.5% agar. 



Sterilization: Not specified. 



Use: Cultivation of molds. 



Added nutrients : The authors added 2.0% 

 of any desired carbohydrate, alcohol, etc. 



Reference : Park, Williams and Krumwiede 

 (1924 p. 134). 



2088. Heinemann's Beer Wort Agar 



Constituents : 



1. Beer wort 1000.0 cc. 



2. Agar 1.5% 15.0 g. 



Preparation : 



(1) Autoclave beer wort at 120° for 5 

 minutes. 



(2) Cool. 



(3) Filter. 



(4) Dissolve 1.5% agar in the filtrate. 



(5) Clarify with the white of egg. 

 Sterilization: Not specified. 



Use: Cultivation of molds, yeast, etc. 

 Variants : 



(a) Dombrowski cultivated milk yeast 

 in a medium prepared by dissolving 

 1.5%agar in wort. 



(b) Janke cultivated acetic acid bacteria 

 found in beers on a medium prepared 

 by dissolving 2.0% agar and 2.0% 

 gelatin in hopped Lager beer wort of 

 12.75° Ballings, clarified with egg 

 white, filtered thru cotton, distributed 

 in 50.0 cc. lots and sterilized by the 

 discontinuous method in the steamer. 



(c) Harvey cultivated trichophyta, 

 molds, yeasts, etc., in a medium 

 prepared by dissolving 1.5% agar in 

 beer wort diluted to a specific gravity 

 of 1.1. 



References: Heinemann (1905 p. 128), 

 Dombrowski (1910 p. 380), Lohnis (1913 p. 

 88), Janke (1916 p. 6), Harvey (1921-22 

 p. 113), Klimmer (1923 p. 207), Park, 

 Williams and Krumwiede (1924 p. 134) 



2089. Groenewege's Indican Malt Agar 



Constituents: 



1. Malt agar 100.0 cc. 



2. Indican (0.1%) 1.0 g. 



Preparation : 



(1) Prepare malt agar. 



(2) Add 0.1% indican to (1). 

 Sterilization: Not specified. 



Use: Cultivation of Phytobacter lycopersi- 

 cum n. sp. (causing tomato rot). Author 

 reported that the indican was de- 

 composed. 



Reference: Groenewege (1913 p. 24). 



