S04 CURRENT PROBLEMS ON YEASTS 



6. Hydrogenated+CH^— CO— CH3->Protoplasm+CH3CHOHCH3 



protoplasm Acetone Isopropyl alcohol 



7. Hydrogenatcd+CbHi.Oe-^Protoplasm+CbHi^Ob 



protoplasm Levulose Mannite 



Kluyver and Donker believed that the dehydrogenation theory accounts for the facts 

 better than Neuberg's theory of Cannizzaro rearrangements. Neuberg cannot ex- 

 plain the formation of certain compounds found in fermentation mixtures such as 

 isopropyl alcohol, 2,3-butylene glycol, mannitol, etc. It was also argued that the 

 new theory suggests an explanation for assimilation and dissimilation. In this theory 

 the protoplasm acts as a catalyzer like nickel and platinum in chemical reactions. In 

 fermentation the protoplasm is charged with hydrogen. 



GLYCEROL FERMENTATION 



This product is of interest on account of the fact that during times of military 

 emergency it may become scarce. During the World War the nations involved had 

 to develop new sources of glycerol. In a former paragraph in which Neuberg's con- 

 ception of the chemistry of alcoholic fermentation was shown, the formation of 

 glycerol was explained. While Neuberg and Reinfurth were able to explain the forma- 

 tion of glycerol, Connstein and Llidecke placed it on a practical basis. Neuberg and 

 Reinfurth' demonstrated the function of the sodium sulphite. 



Connstein and Llidecke,- seeking to find other sources of glycerol for use by the 

 German army during the World War, found that if the yeast fermentation of sugar 

 was carried out in an alkaline solution, the amount of glycerol could be greatly in- 

 creased. The early work was done with a number of different alkaline salts. However, 

 on account of the difficulty of preventing the entrance and growth of bacteria, sodium 

 sulphite was added to the mixture. With this salt they secured still greater yields of 

 glycerol. When sodium sulphite amounting to 40 per cent of the sugar present was 

 used, the glycerol was equivalent to 23.1 per cent of the sugar present; when the 

 sulphite was increased to 100 and 200 per cent of the sugar, the glycerol amounted to 

 30.1 and 36.7 per cent respectively. This method was used by the German mihtary 

 authorities for producing glycerol. Eventually, 1,000,000 kilos were being produced 

 per month. Twenty-five per cent of the sugar appeared as glycerol; other by-products 

 such as alcohol and acetaldehyde were also secured. 



The United States Bureau of Internal Revenue also arrived at this method after 

 learning through Dr. Alonzo Taylor that the Germans were making glycerol'' by 

 fermentation. Eoff ct alJ used Saccharomyces eUipsoidcus with diluted black-strap 

 molasses as the substrate. The most favorable concentration of sugar was 17-20 gm. 

 per 100 cc. Between 20 and 25 per cent of the sugar was fermented to glycerol. 



■ Neuberg, C, ami Reinfurth, E.: Biochcui. Zlsriir., 89, 365. tqiS; 92, 234. iqicS. 



- Connstein, \V., and Llidecke, K.: Ber. d. dculsch. Clicm. Ccsc'IsrIi.ifl, 52, 1385-gi. 1919. 



i Ling. A. C: J. Soc. Client. Ind., 38, 175-77. iQiQ. 



J Eoff, J. R., Linder, VV. V., and Beyer, G. F.: J . Ind. I'Jig. Client., 11, 842-45. 1919. 



