202 EXPERIMENT STATION RECORD. [Vol. 37 



well as on the decomposition of individual organic compounds in the course of 



these processes. Pyroraceraic acid appeared among the decomposition products 

 in both cases. In the work submitted the effect of the addition of raetliylene 

 blue on the process of decomposition of pyroracemic acid resulting In the forma- 

 tion of acetaldehyde and carbon dioxid was determined. 



In general, it is concluded that methylene blue retards the decomposition of 

 potassium pyroracemate by old yeast and the sprouts of wheat, especially 

 during the first hours of the reaction. A slight stimulation, however, was ob- 

 served with pea seeds. The formation of acids takes place along with the 

 activity of carboxylase. Methylene blue is considere<l to take up the hydrogen 

 of water and thus favor the accumulation of acids through the remaining 

 oxygen. 



Activity of reductase and carboxylase in decomposition of lactic acid by 

 yeasts, V. I. Pai.laoin, D. A. Saiunin, and E. I. LovciiiNovsKAfA (Izr. hup. 

 Akad. Nauk (liul. Acad. Imp. Sci Petrograd), 6. ser., 1915, No. 8, pp. 701-71S).— 

 The results of the investigation reported are summarized as follows; 



The decomposition of potassium lactate by dead yeast in the presence of 



methylene blue leads to a splitting off of carbon dioxid with the production 



of acetaldehyde. Theoretically, one-half of the carbon dioxid should be in the 



free .state and the other combined as pota.ssium carbonate, but in reality a 



much larger quantity of carbon dioxid is given off. If the decomposition of 



potassium lactate by dead yenst takes place in a current of air oxygen is ener- 



CO 

 getically absorbed and the ratio -^— approaches unity. 



The decomposition of lactic acid by yeasts in the presence of a hydrogen 

 acceptor consi.sts of, first, the separation of hydrogen by re<lu(t:ise with the 

 production of pyroraccnuc acid and, secondly, the splitting off of tarbun dicixid 

 from the pyroracemic acid through the action of carboxylase, with the produc- 

 tion of acetaldehyde. Since pyroracemic acid Is considennl to be an inter- 

 mediate product of nlcoholic fermentation, its production from lactic acid is 

 considered to offer new i)roof that lactic acid is an intermediate product of 

 alcoholic fermentation. 



Decomposition of lactic acid by killed yeast, V. I. Paluvdin (W. Pali.adin) 

 and D. A. Saiunin {Izv. hup. Akad. Nauk (liul. Acad. Imp. Sci. Petrograd), 6. 

 scr., 1916. No. S. pp. 1^7-19^1 ; Biochcm. Jour., 10 (1916). No. 2, pp. lSS-196).— 

 The authors endeavored to determine under what conditions the decompositii»n 

 of lactic acid would produce alcohol instead of acetaldehyde. Methylene blue 

 as ordinarily u.sed for a hydrogen receptor was replaced by pyrornceuiic add 

 which, when decomposed by carboxyla.se, yields acetaldehyde. The data sub- 

 mitted, while not considered to prove conclusively that lactic acid is the inter- 

 mediate product of alcoholic fermentation, are indicated as showing that alcohol 

 does not present the result of decomposition but the product of reduction of 

 acetaldehyde by removii\g the hydrogen from one of the intermediate products 

 of the decomposition of glucose. 



Investigations on the significance of hydrogen in 'alcoholic fermentation and 

 respiration have shown that on the reductions depend the anaerobic oxidation.s. 

 During the formation of the interme<liate products in the molecule of glucose 

 the hydrogen and not the oxygen is displace<l. The chemical proce.s.ses of alco- 

 holic fermentation and respiration can not be explained by reactions of decom- 

 position alone, as the hydrogen Is di.splaced not only within the confines of one 

 molecule but also passes from one molecule into another. Points in favor of 

 the theory that lactic add is an intermediate product In alcoholic fermentation 

 are discussed. 



