Abstract
We have developed a system for the comprehensive bioconversion of a series of organic chemicals through the living cells of recombinant microbes (living cells-based combinatorial chemistry; CellCombiChem). This attempt started with recombinant Escherichia coli expressing bacterial genes involved in biphenyl degradation (metabolism). The biphenyl degradation is carried out through four enzymes : biphenyl dioxygenase (BphA), dihydrodiol dehydrogenase (BphB), 2, 3-dihydrodiol dioxygenase (BphC), and hydrolase (BphD). We succeeded in synthesizing various oxidized compounds from a series of aromatic compounds, e.g. phenyl heterocycles and flavonoids, by using E. coli expressing these enzyme genes systematically (bphA, synthesis of 1, 2-cis-dihydrodiol; bphA+bphB, 1, 2-diol; bphA+bphB+bphC, picolinic acid; bphA+bphB+bphC+bphD, carboxylic acid). In this bphA (bphA1A2A3A4), bphA1 (2072) evolved by family (DNA) shuffling, which has a wide substrate preference, was used. Many of the converted compounds were novel, and some of them showed potent antioxidative activity.
