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Accelerated Electro-Fermentation of Acetoin in Escherichia coli by Identifying Physiological Limitations of the Electron Transfer Kinetics and the Central Metabolism

Beblawy, Sebastian; Philipp, Laura-Alina; Gescher, Johannes

Abstract:
Anode-assisted fermentations offer the benefit of an anoxic fermentation routine that can be applied to produce end-products with an oxidation state independent from the substrate. The whole cell biocatalyst transfers the surplus of electrons to an electrode that can be used as a non-depletable electron acceptor. So far, anode-assisted fermentations were shown to provide high carbon efficiencies but low space-time yields. This study aimed at increasing space-time yields of an Escherichia coli-based anode-assisted fermentation of glucose to acetoin. The experiments build on an obligate respiratory strain, that was advanced using selective adaptation and targeted strain development. Several transfers under respiratory conditions led to point mutations in the pfl, aceF and rpoC gene. These mutations increased anoxic growth by three-fold. Furthermore, overexpression of genes encoding a synthetic electron transport chain to methylene blue increased the electron transfer rate by 2.45-fold. Overall, these measures and a medium optimization increased the space-time yield in an electrode-assisted fermentation by 3.6-fold.

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Verlagsausgabe §
DOI: 10.5445/IR/1000129899
Veröffentlicht am 19.02.2021
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Angewandte Biowissenschaften (IAB)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2020
Sprache Englisch
Identifikator ISSN: 2076-2607
KITopen-ID: 1000129899
Erschienen in Microorganisms
Verlag MDPI
Band 8
Heft 11
Seiten Art.-Nr.: 1843
Vorab online veröffentlicht am 23.11.2020
Schlagwörter electro-fermentation; acetoin; methylene blue; bulk chemicals; metabolic engineering; Escherichia coli
Nachgewiesen in Scopus
Web of Science
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