METHOD FOR ISOLATING AND PURIFYING ANTHRANILIC ACID FROM FERMENTED SOLUTION

PURPOSE:To recover high-purity anthranilic acid in high recovery ratio by eliminating cells of bacteria from a fermented solution of anthranilic acid, decoloring the solution by a specific method, then concentrating under a specific condition and subjecting anthranilic acid to isoelectric point precipitation. CONSTITUTION:First, cells of bacteria are removed from a fermented solution of anthranilic acid. Then the degermed fermented solution is adjusted to pH5-10 and passed as a feed solution through decoloring resin column, a dyestuff (crystallization inhibitor) of the degermed fermented solution is adsorbed on a decoloring resin and decolored. Successively, the decolored fermented solution is concentrated while adjusting the solution to pH7-11. Then, pH of the concentrated solution is adjusted to an isoelectric point of anthranilic acid to crystallize and precipitate anthranilic acid. Finally, precipitate of anthranilic acid is separated from crystal mud. An amphoteric ion exchange resin, for example, is used as the decoloring resin.