* 
1911] CURRENT LITERATURE 235 
of phosphates. For a clearer understanding of a number of recent papers on 
the subject by these writers, their views may be outlined briefly here. 
_ The view of HarpEeNn and Youne, as expressed in a number of former 
papers, on the manner in which the addition of phosphates to a fermenting 
mixture of yeast juice and sugar causes an increased evolution of carbon 
dioxid, is derived from the following observations. When phosphates are 
added to a fermenting mixture of glucose and yeast juice, the amount of car- 
bon dioxid evolved from the fermenting mixture is greatly increased. e 
extra carbon dioxid is all given off during an initial period of accelerated 
fermentation, after which the rate of evolution decreases and continues at a 
iform rate. During the initial period of fermentation, the phosphates enter 
into combination with the sugar in a form not precipitable by ammoniacal 
magnesium citrate. During the second or uniform period of fermentation, 
the phosphates are again set free. The carbon dioxid given off during the 
initial period is chemically equivalent to the amount of phosphate added... 
These facts are formulated in the following equations. 
I. 2C6H10s+2R,HPO,= 2CO,+2C,Hs0+2H,0+ CsH0,(PO,R2)2 
Tl. CéH10,(PO,R.)2+2H.0 = CoH0s+2R.HPO, 
According to this view, the phosphate combines with the sugar to form a 
hexose-phosphate. This reaction gives the extra carbon dioxid evolved during 
the initial period after the addition of a phosphate, while the rate of the second 
Teaction determines the steady rate of fermentation at which the simple sugars 
are fermented by yeast juice without the addition of phosphates. 
The view of Iwanorr differs from the foregoing chiefly in the following 
details. The phospho-organic compound formed in a mixture of sugar, zymin, 
or “Hefanol” and a phosphate is a triose-phosphate and not a hexose-phos- 
Phate. The formation of the triose-phosphate is not necessarily accompanied 
by the evolution of carbon dioxid, because the combination takes place also 
When a phosphate is added to the filtrate of a sugar solution which has been 
fermented by zymin. Therefore, the combination may take place without 
the accompaniment of fermentation or the evolution of carbon dioxid. 
Further evidence in support of his interpretation is given by [WANOFF in a 
Fecent paper. The main facts and conclusions of this paper may be stated 
briefly, without going into the experiments upon which they are based. It is 
found that the filtrate of a mixture of zymin and saccharose in water fermented 
one day is capable of combining with phosphates, but that this power of com- 
bination is lost when the filtrate is heated. The sugar which can be in part 
liberated from the phospho-organic compound is not fermentable by living 
yeast. Further, “Hefanol” washed with water will ferment the phospho-organic 
compound (triose-phosphate of the author), but not glucose, even after the 
addition of phosphate. 
2 Wainer ee 
, _‘lWANorr, S., Ueber die Bildung der phosphororganischen Verbindungen und 
ihte Rolle bei der Zymasegiirung. Centralbl. Bakt. II. 24:1-12. 1909. 
