{"id":{"repo_id":"rice","oai_identifier":"oai:repository.rice.edu:1911/64664"},"canonical_url":"https://search.dev.ndltd.org/etd/rice/oai:repository.rice.edu:1911/64664","repository":{"repo_id":"rice","name":"Rice University","base_url":"https://repository.rice.edu/server/oai/request"},"display":{"title":"Metabolic Engineering and Transhydrogenase Effects on NADPH Availability in Escherichia coli","abstract":"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.","abstract_html":"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.","abstract_has_math":false,"creators":["Jan, Joanna"],"institution":"Rice University","degree_name":"Master of Science","degree_level":"Masters","degree_discipline":"Engineering","degree_department":null,"school":null,"contributors":[],"advisors":["San, Ka-Yiu"],"committee_chairs":[],"committee_members":["Bennett, George N.","Gonzalez, Ramon"],"year":2012,"date_issued":"2012-09-05","date_published":"2012-09-05","updated_at":"2026-07-24T04:10:21Z","subjects":["Metabolic engineering","Escherichia coli","Nadph","Cofactor","Transhydrogenase"],"languages":["eng"],"rights":["Copyright is held by the author, unless otherwise indicated. 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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."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Metabolic Engineering and Transhydrogenase Effects on NADPH Availability in Escherichia coli"]}]}],"canonical_facts":{"dc:contributor.advisor":["San, Ka-Yiu"],"dc:contributor.committeemember":["Bennett, George N.","Gonzalez, Ramon"],"dc:creator":["Jan, Joanna"],"dc:date.accessioned":["2012-09-06T04:18:07Z","2012-09-06T04:18:10Z"],"dc:date.available":["2012-09-06T04:18:07Z","2012-09-06T04:18:10Z"],"dc:date.issued":["2012-09-05"],"dc:description.abstract":["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. 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