For the purpose of enzymatic preparation of ADP-glucose (ADPG), bacterial screening was performed to find a strain having a high activity of ADPGpyrophosphorylase which catalyzes the synthesis of ADPGfrom ATPand glucose-1-phosphate. A cell-free extract of Arthrobacter simplex IFO 12069 showed a strong enzymeactivity for the synthesis ofADPG,which was isolated from the reaction solution by ion-exchange column chromatography and identified by paper and thin-layer chromatography. The enzyme activity of the bacterium reached a maximumin the late logarithmic phase under aerobic growth conditions. Somefactors affecting the ADPGsynthesis, e.g. reaction pH, substrate concentrations, divalent cations, inhibitors and activators, were studied with an ammoniumsulfate fraction, 30~50%saturation as the enzyme preparation.

For the purpose of enzymatic preparation of ADP-glucose (ADPG), bacterial screening was performed to find a strain having a high activity of ADPG pyrophosphorylase which catalyzes the synthesis of ADPG from ATP and glucose-I-phosphate. A cell-free extract of Arthrobacter simplex IFO 12069 showed a strong enzyme activity for the synthesis of ADPG, which was isolated from the reaction solution by ion-exchange column chromatography and identified by paper and thin-layer chromatography. The enzyme activity of the bacterium reached a maximum in the late logarithmic phase under aerobic growth conditions. Some factors affecting the ADPG synthesis, e.g. reaction pH, substrate concentrations, divalent cations, inhibitors and activators, were studied with an ammonium sulfate fraction, 30", 50% saturation as the enzyme preparation.