PURIFICATION OF A MARINE BACTERIAL GLUCOSE-DEHYDROGENASE FROM CYTOPHAGA-MARINOFLAVA AND ITS APPLICATION FOR MEASUREMENT OF 1,5-ANHYDRO-D-GLUCITOL

A novel glucose dehydrogenase (GDH) from a marine bacterium Cytophaga marinoflava IFO 14170 was isolated from its membrane fraction. This GD H catalyzes the oxidation of a hydroxy group of glucose, but does not react in its C-1 position. This enzyme is composed of a single peptide with a mol wt of 67,000. The GDH can react under high salinity. The o ptimum pH is around 8.0, showing a typical property of marine bacteria l enzymes. Using this novel enzyme, an enzymatic determination of 1,5- anhydro-D-glucitol (1,5AG) utilizing 2,6-dichrolophenolindophenol (DCI P) and phenazine methosulfate (PMS) as electron mediators was caried o ut. A good linear correlation was observed from 0.5 mM to 4 mM of 1,5A G.