Process for preserving the phosphorylating activity of yeast, applied to the production of fructose-1,6-diphosphate

A process for preserving the phosphorylating activity of brewer's yeast applied to the production of fructose-1,6-diphosphate, wherein the following steps are provided:

• (a) permeabilizing the cell wall, in order to allow fructose-1,6-diphosphate to flow out from the cytoplasm, by adding 0.5 volume hypertonic solution to 1 volume of a yeast suspension of 60% w/v yeast in tap water, and heating for one hour to 35.degree. C. under slow stirring;
• (b) preparing a disintegrated yeast extract suitable for use as a protecting agent against the oxidation of the SH groups of the glycolytic enzymes during the repeated phoshorylation cycles, by disintegrating a yeast suspension in a hypertonic solution of 1M glucose and 0.5M potassium phosphate by means of a glass ball homogenizer, incubating the disintegrated cell suspension for 2 h at 28.degree. C., deproteinizing by heating at 100.degree. C. for 10' and centrifuging 8000 revolutions for 30';
• and
• (c) immobilizing the glycolytic enzymes inside the cell, by cross-linking with intracellular proteins, wherein glutaraldehyde is added to the suspension of the permeabilized yeast cells, and to which is added disintegrated yeast extract at a final concentration of glutaraldehyde of 0.25-1% w/v, at 28.degree. C. under constant and slow stirring.