Levoglucosan Dehydrogenase Involved in the Assimilation of Levoglucosan inArthrobactersp. I-552

A levoglucosan (1,6-anhydro-beta-D-glucopyranose)-using bacterium, isolated from soil, was identified. It was shown to belong to the genus Arthrobacter and tentatively named Arthrobacter sp. I-552. A novel enzyme catalyzed the dehydrogenation of levoglucosan to form 1,6-anhydro-beta-D-ribo-hexopyranos-3-ulose (3-keto levoglucosan), using NAD+ as an electron acceptor, i.e. NAD+: 1,6-anhydro-beta-D-glucopyranose oxidoreductase (trivial name: levoglucosan dehydrogenase). This enzyme was purified and characterized. A possible reaction scheme for the glucose formation was proposed. This pathway for levoglucosan use is distinct from those in yeast and fungi.