Purification and characterization of gallic acid decarboxylase from Pantoea agglomerans T71

Oxygen-sensitive gallic acid decarboxylase from Pantoea (formerly Enterobac ter) agglomerans T71 was purified from a cell extract after stabilization b y reducing agents. This enzyme has a molecular mass of approximately 320 kD a and consists of six identical subunits. It is highly specific for gallic acid. Gallic acid decarboxylase is unique among similar decarboxylases in t hat it requires iron as a cofactor, as shown by plasma emission spectroscop y (which revealed an iron content of 0.8 mol per mol of enzyme subunit), sp ectrophotometric analysis (absorption shoulders at 398 and 472 nm), and inh ibition of the enzyme activity by 2,2'-bipyridyl, o-phenanthroline, and EDT A. Another interesting feature of this strain is the fact that it contains a tannase, which is used together with the gallic acid decarboxylase in a t wo-enzyme resting cell bioconversion to synthesize valuable pyrogallol from readily available tannic acid.