CHAPTER LXV, 



ENZYMES DECOMPOSING DISACCHABIDES AND 

 POLYSACCHARIDES. 



By Dr. A. BAIL 



327. Invertase. 



THE best known and most frequently investigated yeast enzyme 

 is invertase, which was originally termed invertin, and has also 

 been called saccharase, sucrase and euinvertase. 



In its occurrence it is one of the most widespread of the 

 enzymes. In the animal organism it is found in numerous organs, 

 especially in the mucous membrane of the small intestine (particu- 

 larly in warm-blooded animals) : and it has also been found, by 

 ERLENMEYER and A. von PLANTA (I.), AXENFELD (I.) and others, 

 in insects. In the vegetable kingdom it occurs in the majority of 

 plant organs : leaves, flowers and fruit (also in hop cones), &c., 

 though in far smaller amount than in the lower fungi, mould 

 fungi, yeasts and bacteria. 



Invertases of different origin are not always of identical compo- 

 sition ; and differences of action on saccharose are also observed 

 in the invertases according to the method of preparation employed 

 compare FERNBACH (VI.). For this reason, BAU (XII.) pro- 

 posed the name " euinvertase " for the invertase occurring in the 

 true yeast, until further investigation had shown whether the 

 saccharose-dissociating enzymes obtained from such highly diver- 

 gent materials were really identical. A special example of the 

 variation in the individual invertases is afforded byMonilia Candida 

 (p. 444, vol. ii.) which, though decomposing and fermenting 

 saccharose, does not, in the opinion of FISCHER" and P. LIND- 

 NER (II.), contain true invertase. HAHN (III.) regards the 

 enzyme of this fungus as an endoenzyme which is possibly com- 

 bined with the protoplasm ; and perhaps it is merely an enzy- 

 mogen. BUCHNER and MEISENHEIMER (I.), who investigated the 

 expressed juice of Monilia Candida, found that the enzyme will 

 not diffuse through parchment paper, differing remarkably, in 

 this respect, from yeast invertase. 



Invertase occurs extensively in yeasts, being found in all 



