Bioproduction of D-Psicose from Allitol with Enterobacter aerogenesIK7: A New Frontier in Rare Ketose Production

D-Psicose, a new alternative sweetener, was produced from allitol by microbial oxidation of the newly isolated strain Enterobacter aerogenesIK7. Cells grown in tryptic soy broth medium (TSB) supplemented with D-mannitol at 37 °C were found to have the best oxidation potential. The cells, owing to broad substrate specificity, oxidized various polyols (tetritol, pentitol, and hexitol) to corresponding rare ketoses. By a resting cell reaction, 10% of allitol was completely transformed to the product D-psicose, which thus becomes economically feasible for the mass production of D-psicose. Finally, the product was crystallized and confirmed to be D-psicose by analytical methods.