Inducible pyrrole-2-carboxylate decarboxylase, which catalyzes the decarboxylation of pyrrole-2-carboxylate to pyrrole and CO2 in stoichiometric amounts, was purified from Bacillus megaterium PYR2910. The purity of the enzyme was shown by SDS/PAGE and gel-permeation HLPC. The enzyme has a molecular mass of approximately 98 kDa and consists of two identical subunits. It is highly specific for pyrrole-2-carboxylate, and also catalyzes the reverse reaction, the carboxylation of pyrrole. A unique feature of this enzyme is its requirement of an organic acid, such as acetate, propionate, butyrate or pimelate. A possible catalytic mechanism including a cofactor function of organic acid is discussed.