Invertase, preparation

Although dilute aqueous acid hydrolyzed the methyl and benzyl a-D-fructofuranosides approximately 8 and 16 times as rapidly as sucrose, their method of preparation showed them to be unaffected by any of the enzymes active in a fermenting yeast suspension. Purified yeast invertase, proven free of a-D-glucosidases (maltases), could therefore contain no enzyme capable of hydrolyzing the above two a-D-fructo-furanosides, but did contain constituents that readily cleaved the beta isomers and also sucrose. The latter is accordingly a /S-D-fructofuranos-ide. When the evidence is put in this way, the present uncertainties as to whether purified invertase preparations include one or a number of /3-D-fructofuranosidases, and whether or not sucrose, methyl and... 

L.Wallerstein 1933 Invertase Invertase preparation and production procedure... 

As regards the occurrence of /3-D-linked disaccharides in the absence of a /3-D-linked substrate, one is tempted to conclude that these oligosaccharides are synthesized by the enzymic reversion of D-glucose by a /3-D-glucosidase. As White and Maher100 have found that their honey-invertase preparation had no /3-D-glucosidase activity, it would appear that these sugars are carried into the hive as constituents of nectar. 

When acted upon by invertase preparations containing melibiase (from brewers yeast), all the raffinose oligosaccharides, including planteose, are hydrolyzed to monosaccharides.23,42... 

Invertase prepared from Saccharomyces cerevisiae and S. carlsbergensis is used in the preparation of soft center candies, fondants, and invert sugars. 

Kinetics of Hydrolysis of Sucrose, Raffinose, and Inulin by Purified Yeast Invertase Preparations... 

In addition to invertase ( 8-fructofuranosidase) and the a-galactosidase of brewers yeast, purified yeast invertase preparations contain a j8-gluco-sidase and the otherwise unknown j5-mannosidase. However, there is no evidence for the existence of a jS-galactosidase, an a-mannosidase, an a-gluco-sidase, or an a-fructofuranosidase (12). Phenyl /3-fructopyranoside also is not appreciably hydrolyzed by yeast invertase (37). 

For this reason yeast invertase preparations contain little if any of this enzyme, and to obtain it very mild autolysis conditions must be employed. Dried yeasts seem to be a particularly good source 66). Such preparations contain considerable quantities of invertase, but if the low-temperature autolysate is treated with limited portions of activated aluminum hydroxide, the a-glucosidase is preferentially adsorbed and then may be eluted with solutions of secondary phosphates 66). 

Incomplete hydrolysis of sucrose by yeast invertase preparations produces, in addition to D-glucose and D-fructose, a number of oligosaccharides which are then hydrolyzed to different ratios of D-glucose and D-fructose 180y 181), Thus, one action of yeast invertase is to transfer D-fructosyl units to form 2— 6 D-fructofuranose linkages. (See also Chapter IX.)... 

Consequently, a sucrose solution (60 g.) in water (54 ml.) was adjusted to pH 4.5 with acetic acid. 6 ml. of a commercial yeast invertase preparation, Sumasuco invertase concentrate (Sugar Manufacturers Supply Co., London) was added and the solution was kept at 20° for 40 minutes. The reaction was stopped by boiling for a few seconds. A sample was analyzed paper chromatographically and showed, in addition to sucrose, glucose, and fructose, three oligosaccharide spots with Rf values lower than that of sucrose. 

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