caa a22 4500 605502226 CHVBK 20210128100604.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s00253-015-6387-6 doi (NATIONALLICENCE)springer-10.1007/s00253-015-6387-6 Metabolic flux analysis of Escherichia coli MG1655 under octanoic acid (C8) stress [Elektronische Daten] [Yanfen Fu, Jong Yoon, Laura Jarboe, Jacqueline Shanks] Systems metabolic engineering has made the renewable production of industrial chemicals a feasible alternative to modern operations. One major example of a renewable process is the production of carboxylic acids, such as octanoic acid (C8), from Escherichia coli, engineered to express thioesterase enzymes. C8, however, is toxic to E. coli above a certain concentration, which limits the final titer. 13C metabolic flux analysis of E. coli was performed for both C8 stress and control conditions using NMR2Flux with isotopomer balancing. A mixture of labeled and unlabeled glucose was used as the sole carbon source for bacterial growth for 13C flux analysis. By comparing the metabolic flux maps of the control condition and C8 stress condition, pathways that were altered under the stress condition were identified. C8 stress was found to reduce carbon flux in several pathways: the tricarboxylic acid (TCA) cycle, the CO2 production, and the pyruvate dehydrogenase pathway. Meanwhile, a few pathways became more active: the pyruvate oxidative pathway, and the extracellular acetate production. These results were statistically significant for three biological replicates between the control condition and C8 stress. As a working hypothesis, the following causes are proposed to be the main causes for growth inhibition and flux alteration for a cell under stress: membrane disruption, low activity of electron transport chain, and the activation of the pyruvate dehydrogenase regulator (PdhR). Springer-Verlag Berlin Heidelberg, 2015 Octanoic acid nationallicence Toxicity nationallicence Escherichia coli nationallicence Metabolic flux analysis nationallicence Fu Yanfen Department of Chemical and Biological Engineering, Iowa State University, 4136 Biorenewables Research Laboratory, 50011-2230, Ames, IA, USA aut Yoon Jong Department of Chemical and Biological Engineering, Iowa State University, 4136 Biorenewables Research Laboratory, 50011-2230, Ames, IA, USA aut Jarboe Laura Department of Chemical and Biological Engineering, Iowa State University, 4136 Biorenewables Research Laboratory, 50011-2230, Ames, IA, USA aut Shanks Jacqueline Department of Chemical and Biological Engineering, Iowa State University, 4136 Biorenewables Research Laboratory, 50011-2230, Ames, IA, USA aut Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/10(2015-05-01), 4397-4408 0175-7598 99:10<4397 2015 99 253 https://doi.org/10.1007/s00253-015-6387-6 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00253-015-6387-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Fu Yanfen Department of Chemical and Biological Engineering, Iowa State University, 4136 Biorenewables Research Laboratory, 50011-2230, Ames, IA, USA aut NATIONALLICENCE 700 1- Yoon Jong Department of Chemical and Biological Engineering, Iowa State University, 4136 Biorenewables Research Laboratory, 50011-2230, Ames, IA, USA aut NATIONALLICENCE 700 1- Jarboe Laura Department of Chemical and Biological Engineering, Iowa State University, 4136 Biorenewables Research Laboratory, 50011-2230, Ames, IA, USA aut NATIONALLICENCE 700 1- Shanks Jacqueline Department of Chemical and Biological Engineering, Iowa State University, 4136 Biorenewables Research Laboratory, 50011-2230, Ames, IA, USA aut NATIONALLICENCE 773 0- Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/10(2015-05-01), 4397-4408 0175-7598 99:10<4397 2015 99 253