OXIDATION OF SUGARS BY AN ENZYME PREPARATION FROMAEROBACTER AEROGENES

Cell-free extracts of Aerobacter aerogenes grown on a medium containing yeast extract, glucose, and salts, oxidized D-α-fructoheptose (2-C-hydroxymethyl-D-glucose), glucose, gluconate, and other hexoses and pentoses. The enzymes were in a particulate fraction and were difficult to purify. This cell-free enzyme system required magnesium or certain other divalent metal ions as activators and was not stimulated by any coenzyme tested. Phosphorylation did not appear to be involved. The pH-stability and pH-activity curves for the crude enzyme preparation were plotted and the Kmvalue for D-α-fructoheptose determined. The same enzyme system is apparently involved for all substrates and appears to be specific for sugars having the same configuration as glucose at the second and fourth carbon atoms.