﻿2 6 BOTANICAL GAZETTE [January 



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Medium C— Inulin, 5^™; KNO3, 0.5^"^; CaCls, 0.25 s"^; Na2So4, 

 0.25s™; NaH2P04, 0.25s™; MgSo4, o.2^™; FcaCle, trace; water to make , 



500". 



About 50*''' of this were placed in each of a number of small 

 Erlenmeyer flasks, which, after sterilization, were inoculated 

 with spores of Penicillium. As in the former case, so here, the 

 fungus grew well, and its growth was followed after a few days 

 by the appearance of a reducing sugar in the culture medium. 

 After nine days of growth the culture fluid contained no inulin. 



It was found that Aspergillus niger grown in the culture fluids 

 described above caused, after a few days of growth, the same 

 appearance of levulose in the solution. After trying a number 

 of media the following was preferred as producing uniformly 

 vigorous growths of the fungi : 



Medium D.— Inulin, 15^"^; peptone (Griibler's), 7.5^""; KNO3, 2^™ 

 CaCla, i^"^; Na2S04. i^™;MgS04. 1^"^; NaH^PO^, i^™ ; FeS04, trace 

 water to make 1500^^. 



This solution gave about equally good results when 25^^ were 

 placed in small (125*^^) Erlenmeyer flasks, or when 75*^^ were 

 placed in larger (500''^) flasks. Since the growth is almost 

 entirely on the surface, a larger percentage of mycelia is obtained 

 from a given quantity of culture medium if the fluid is in a thin 

 layer. The cultures were grown in the dark at a temperature of 



25-30° c 



METHOD OF OBTAINING PREPARATIONS OF INULASE. 



Cultures of the fungi were grown as described above until 

 about a week old; the mycelia were then filtered from the cul- 

 ture fluid, washed in distilled water, torn apart with needles, and 

 thrown into a mixture of three parts of absolute alcohol and one 

 part of ether. After remaining in the alcohol and ether about 

 five minutes, the material was filtered off on a Biichner funnel 

 and dried. The mass when ground to a powder yielded, in the 

 case of Aspergillus, a black, and in the case of Penicillium, a 

 grayish-green powder. 



The above method was suggested by the procedure recom- 

 mended by Alberts as a simple way to obtain the zymase from 



sEinfacher Versuch zur Veranschaulichung der Zymase. Ber. Deutsche Chem. 

 Gesell. 33: 3775. 1900. 



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