A novel biotransformation of 2-formyl-6-naphthoic acid to 2,6-naphthalene dicarboxylic acid by Pseudomonas sp. for the purification of crude 2,6-naphthalene dicarboxylic acid.

Crude 2,6-naphthalene dicarboxylic acid was purified by Pseudomonas sp. HN-72 which biotransformed the major impurity of 2-formyl-6-naphthoic acid into 2,6-naphthalene dicarboxylic acid. The biotransformation yield reached 100% when the reaction was performed at 40 degrees C for 1 h, in 200 ml KH(2)PO(4)/KOH buffer (50 mM, pH 8.0), with 0.2% (w/v) crude 2,6-naphthalene dicarboxylic acid and 2.5 mg dry cell wt/ml.