PURIFICATION METHOD OF CRUDE NAPHTHALENE DICARBOXYLIC ACID USING BENZALDEHYDE DEHYDROGENASE FROM RECOMBINATED MICROORGANISM AND 2,6-NAPHTHALENE DICARBOXYLIC ACID IN CRYSTALLINE FORM OBTAINED BY USING THE SAME

摘要

A method for purifying crude naphthalene dicarboxylic acid is provided to environment-friendly mass-produce crystal form of 2,6-naphthalene dicarboxylic acid with high purity by purifying and crystallizing crude naphthalene dicarboxylic acid under the proper conditions using benzaldehyde dehydrogenase purified from a recombinant microorganism converting 2-formyl-6-naphthoic acid into naphthalene dicarboxylic acid. A method for purifying crude naphthalene dicarboxylic acid using benzaldehyde dehydrogenase comprises the steps of: (a) reacting benzaldehyde dehydrogenase which is isolated and purified from a recombinant microorganism obtained by transformation using a recombinant expression vector including benzaldehyde dehydrogenase gene xylC derived from Sphingomonas aromaticivorans KCTC 2888 described as SEQ ID : NO. 1 or a gene having more than 90% homology to the gene or is isolated and purified from a recombinant microorganism obtained by transformation using a recombinant expression vector including benzaldehyde dehydrogenase gene xylC derived from Pseudomonas putida ATCC 33015 described as SEQ ID : NO. 4 or a gene having more than 90% homology to the gene with crude naphthalene dimethylcarboxylic acid to convert 2-formyl-6-naphthoic acid into 2,6-naphthalene dicarboxylic acid ; (b) putting an acidic solution to the reaction solution obtained from the step(a) to adjust the pH thereof, reacting it with agitation at a temperature of 10-110 deg.C for 1 minute to 8 hours to crystallize the crude naphthalene dicarboxylic acid; (c) washing the crystallized crude naphthalene dicarboxylic acid to remove impurities therefrom; and (d) drying the washed materials at a temperature of 50-250 deg.C to obtain a pure crystal form 2,6-naphthalene dicarboxylic acid. The method further comprises a step of removing the inactivated enzyme from the reaction product obtained from the step(a).