title: Manipulating respiratory levels in Escherichia coli for aerobic formation of reduced chemical products.
abstract: Optimizing the productivity of bioengineered strains requires balancing ATP generation and carbon atom conservation through fine-tuning cell respiration and metabolism. Traditional approaches manipulate cell respiration by altering air feeding, which are technically difficult especially in large bioreactors. An approach based on genetic regulation may better serve this purpose. With excess oxygen supply to the culture, we efficiently manipulated Escherichia coli cell respiration by adding different amount of coenzyme Q1 to strains lacking the ubiCA genes, which encode two critical enzymes for ubiquinone synthesis. As a proof-of-concept, the metabolic effect of the ubiCA gene knockout and coenzyme Q1 supplementation were characterized, and the metabolic profiles of the experimental strains showed clear correlations with coenzyme Q1 concentrations. Further proof-of-principle experiments were performed to illustrate that the approach can be used to optimize cell respiration for the production of chemicals of interest such as ethanol. This study showed that controlled respiration through genetic manipulation can be exploited to allow much larger operating windows for reduced product formation even under fully aerobic conditions.
authors: Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, China.
authors: Jiangfeng
authors: J
authors: Zhu
authors: Ailen
authors: A
authors: Sánchez
authors: George N
authors: GN
authors: Bennett
authors: Ka-Yiu
authors: KY
authors: San
mesh_terms: D019149:Bioreactors; D004926:Escherichia coli / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D055442:Metabolome; D010084:Oxidation-Reduction; D007652:Oxo-Acid-Lyases / Q000235:genetics; D010100:Oxygen / Q000378:metabolism*; D014451:Ubiquinone / Q000008:administration & dosage
chemical_list: D014451:Ubiquinone; D000431:Ethanol; D007652:Oxo-Acid-Lyases; C025203:Ubiquinone Q1; D010100:Oxygen