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Systems‐wide analysis and engineering of metabolic pathway fluxes in bio‐succinate producing Basfia succiniciproducens
Author(s) -
Becker Judith,
Reinefeld Jasper,
Stellmacher René,
Schäfer Rudolf,
Lange Anna,
Meyer Hanna,
Lalk Michael,
Zelder Oskar,
von Abendroth Gregory,
Schröder Hartwig,
Haefner Stefan,
Wittmann Christoph
Publication year - 2013
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.24963
Subject(s) - isocitrate dehydrogenase , anabolism , biochemistry , flux (metallurgy) , oxidative phosphorylation , citric acid cycle , metabolic engineering , chemistry , metabolic flux analysis , formate dehydrogenase , dehydrogenase , metabolic pathway , zymomonas mobilis , cofactor , enzyme , metabolism , ethanol , ethanol fuel , organic chemistry
Basfia succiniciproducens has been recently isolated as novel producer for succinate, an important platform chemical. In batch culture, the wild type exhibited a high natural yield of 0.75 mol succinate (mol glucose) −1 . Systems‐wide 13 C metabolic flux analysis identified undesired fluxes through pyruvate‐formate lyase (PflD) and lactate dehydrogenase (LdhA). The double deletion strain B. succiniciproducens Δ ldhA Δ pflD revealed a 45% improved product yield of 1.08 mol mol −1 . In addition, metabolic flux analysis unraveled the parallel in vivo activity of the oxidative and reductive branch of the TCA cycle in B. succiniciproducens , whereby the oxidative part mainly served for anabolism. The wild type re‐directed surplus NADH via a cycle involving malic enzyme or via transhydrogenase, respectively, to supply NADPH for anabolism, because the fluxes through the oxidative PPP and isocitrate dehydrogenase, that also provide this cofactor, were not sufficient. This was not observed for the deletion mutants, B. succiniciproducens Δ pflD and Δ ldhA Δ pflD , where PPP and isocitrate dehydrogenase flux alone matched with the reduced anabolic NADPH demand. The integration of the production performance into the theoretical flux space, computed by elementary flux mode analysis, revealed that B. succiniciproducens Δ ldhA Δ pflD reached 62% of the theoretical maximum yield. Biotechnol. Bioeng. 2013;110: 3013–3023. © 2013 Wiley Periodicals, Inc.