534 ENZYMES DECOMPOSING SACCHARIDES. 



Sacch. Pastorianus /., II. and ///., tfacch. ellipsoideus I. and 77. , 

 Sacch. cratericus, by two yeasts from Breslau " Kretschmer" beer, 

 and by culture bottom yeasts of the Frohberg type, though no 

 definite result was obtained with Saaz yeast. In the continued 

 experiments with races of the UF type, twenty-four yeasts fer- 

 mented trehalose, whilst nine others gave negative or indefinite 

 results. A majority of the culture top yeasts fermented this 

 sugar only, rather more than 16 per cent, of them having no 

 effect on trehalose ; and similar behaviour was exhibited by most 

 of the wild yeasts, only five out of thirty-seven races giving no 

 result. With regard to Bau's statement that Logos yeast fer- 

 ments trehalose, Lindner obtained a different result : and whilst 

 Kalanthariantz found that three lactose yeasts split up trehalose, 

 LINDNER (XXXV.) could not obtain any fermentation of this 

 sugar with the same yeasts. 



BAU (XVIII.) has pointed out a general resemblance between 

 the fermentation of trehalose and the course of fermentation of 

 saccharose solution by Monilia Candida, except that the operation 

 proceeds more sluggishly. 



Whereas Bourquelot's experiments indubitably prove that cer- 

 tain mould fungi contain an enzyme (trehalase) capable of splitting 

 up trehalose, there does not seem to be any justification for assuming 

 that this is also the case with the true yeasts so far as present 

 experience extends the contrary being indicated in a striking 

 degree by the irregularity of the decomposition and extreme 

 sluggishness of the fermentation. The case is probably analogous 

 with the behaviour of Monilia Candida in presence of saccharose. 



332. Raffinase. 



MUDIE (I.) discovered, in eucalyptus manna, a sugar, which 

 was afterwards investigated by BERTHELOT (IX.), who called it 

 melitose. This sugar has been already mentioned on p. 526, vol. ii. 

 When Dubrunfaut, in 1850, observed that certain sugars deposited 

 from beet molasses gave a polarimeter reading of over 100 (in the 

 Soleil-Ventzke-Scheibler apparatus), Scheibler at first attributed 

 this circumstance to the presence of an admixture of dextrin. 

 This hypothesis, however, proved untenable, and the name, "plus 

 sugar," was applied to the constituent causing this higher polari- 

 sation in beet sugar. In 1876, Loiseau succeeded in isolating 

 this sugar in a pure state, and named it raffinose, because it was 

 first recovered from sugar-refinery residues. The subsequent 

 exhaustive researches of Tollens and his collaborators, and the 

 simultaneously conducted investigations of Scheibler and Mittel- 

 meier, revealed the identical nature of the sugars, melitose, 

 raflSnose, plus ^ sugar and gossypose. The literature of these 

 highly interesting labours the study of which, in the original, 

 is recommended to all young workers desiring to acquire a know- 



