A fed-batch process was used to produce cis,cis-muconic acid from catechol by recombinant Escherichia coli cells expressing the catA gene, which encodes the Pseudomonas putida mt-2 catechol I,2-dioxygenase responsible for catalyzing ortho-cleavage of catechol, as biocatalysts. We succeeded in producing 415 mM (59.0 g L-1) cis,cis-muconic acid in aqueous solution without generation of by-products in 12 h under the optimal conditions with successive addition of 10 mM catechol. The molar conversion yield based on the amount of consumed catechol was the theoretical value of 100% (mol mol(-1)).