626 EXPERIMENT STATION RECORD. 



presence of 12 percent alcohol and feebly at 16 per cent. Small quan- 

 tities of some of the higher alcohols check its growth. Cane sugar 

 solutions containing meat extract are fermented by it even when con- 

 taining as much as 45 per ceut cane sugar. Salt in small quantity 

 does not check it, while 22 per cent stops it entirely. Solutions con- 

 taining 10 per cent cane sugar and 4 per cent tartaric acid do not 

 admit the growth of the yeast. 



Several other agents of fermentation derived from rice straw are 

 mentioned, among them the organism depended upon for ripening the 

 vegetable cheese, natto, the Javanese arrac, a diastase-yielding fungus 

 and Saccharomyces vordermanni. 



On the behavior of yeast at a high temperature, T. Nakamura 

 {Imp. Univ. Col Agr. [Tokyo] Bui, vol. 3, No. .3, pp. 227-232).— The 

 author experimented with pure cultures of yeast obtained from a single 

 colony. A description of the method of treatment is given. It was 

 found that exposing the yeast in a water bath for li hours at 40° C. or 

 1 hour at 48° C. did not destroy its fermenting power. At a tempera- 

 ture of 52° C. the power to produce fermentation was destroyed if con- 

 tinued for more than 20 minutes. 



It was found that the thermal point at which the fermenting power 

 was destroyed was 50° C. for 30 minutes' exposure. With between 2.5 

 and 30 minutes' exposure at the above temperature, the yeast still gave 

 feeble fermentation for a short time, after which it ceased, although 

 but a very small portion of the sugar had been used up. It is inferred 

 that exposure for 25 minutes to a temperature of 50° C. forms the limit, 

 not only of fermenting power, but life functions as well. 



The effect on the resistant power of the organism of adding various 

 compounds to the culture medium was tested and meat extract, sodinm 

 chlorid, and sodium nitrate served to increase the resisting power of 

 the yeast. 



In an appended note by Dr. O. Loew, the phenomenon of suspended 

 fermenting power in living cells is explained by the statement of Buch- 

 ner l u That the fermentative power is connected with a soluble proteid 

 that can be separated by expressing the yeast under a pressure of 

 400 to 500 atmospheres." This substance, called zymose, coagulates 

 easily, and after a few days loses its active properties. It is similarly 

 affected by heating to 50° C. or more. 



Note on a grape wine fermented by sake yeast, K. Kegami 

 (Imp. Univ. Col Ayr. [Tokyo] Bui., vol. 3, No. 5, pp. 225. 226).— Two liters 

 of freshly prepared grape juice were sterilized by boiling and after 

 cooling inoculated with a pure culture of sake yeast. After 2 months 

 fermentation at from 5 to 20° 0., the clear filtered liquid gave extract 

 1.78 per cent, acidity 0.572 per cent, alcohol 10.30 per cent. The taste 

 was equal to that of the average white wine, but the bouquet was 

 inferior. The yeast can not be used to replace the usual ferments of 

 wine making. 



1 Ber. Deut. Chem. Gesell., 30 (1896), p. 117. 



