PHYTATE DEPHOSPHORYLATION BY FREE AND IMMOBILIZED CELLS OF SACCHAROMYCES-CEREVISIAE

Saccharomyces cerevisiae in the form of baker's yeast, cells cultivate d on a yeast extract-peptone-glucose medium, as well as cells immobili zed in 18% (w/v) polyacrylamide gel showed the ability to hydrolyze 1. 727 mM sodium phytate solution at 45-degrees-C, pH 4.6, in a stirred t ank reactor. Seventy percent yield of dephosphorylation was observed a fter 2 h using a baker's yeast concentration of 5.8 g dry matter per 1 00 ml. Hydrolytic activity at 1.8-2.0 muM Pi min-1 was observed betwee n 1st and 3rd h of the reaction in cells cultured 24 or 48 h. No inhib ition by the substrate was found at sodium phytate concentrations of 0 .587-1.727 mM. After 1.5 h of hydrolysis a single, well distinguished peak of myo-inositol-triphosphate was the main product found. By means of immobilization the stability of the biocatalyst was enhanced 3.3-f old and reached its half-life at 64 ninety-minute runs.