Identification and removal of impediments to biocatalytic synthesis of aromatics from D-glucose: rate-limiting enzymes in the common pathway of aromatic amino acid biosynthesis

Abstract

Increasing the flow of D-glucose equivalents into the common pathway of aromatic amino acid biosynthesis creates a metabolic situation where individual common pathway enzymes become rate-limiting. Such enzymes are unable to convert substrate to product at a rate sufficient to avoid intracellular accumulation of substrate. Export of the accumulating substrate by the host microbe into its culture supernatant results in lowered percent conversions and decreased purity of desired aromatic products. Methodology has now been developed which facilitates rapid identification and removal of impediments to biocatalytic synthesis of aromatics from D-glucose which are caused by rate-limiting, common pathway enzymes