Metabolic Engineering and Transhydrogenase Effects on NADPH Availability in Escherichia coli

[摘要] The ultimate goal in the field of metabolic engineering is improving cellular processes in a rational manner using engineering design principles and molecular biology techniques.The syntheses of several industrially useful compounds are cofactor-dependent.The reducing equivalent NADPH is required in several enzymatic reactions leading up to the synthesis of high-value compounds like polymers, chiral alcohols, and antibiotics.However, it’s a highly costly compound with limited intracellular availability.This study focuses on the genetic manipulation of a whole-cell system using the two transhydrogenase isoforms pntAB and udhA.Two model systems are used: 1) the production of (S)-2-chloropropionate and 2) the production of poly(3-hydroxybutyrate).Results suggest that the presence of udhA increases product yield and NADPH availability while the presence of pntAB has the opposite effect.A maximum product yield of 1.4 mole-product/mole-glucose was achieved aerobically in a pntAB-deletion strain with udhA overexpression, a 150% improvement over the wild-type control strain.

[发布机构] Rice University

[效力级别] engineering