AIMS Bioengineering, 2017, 4(1): 12-27. doi: 10.3934/bioeng.2017.1.12.

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Manganese orchestrates a metabolic shift leading to the increased bioconversion of glycerol into α-ketoglutarate.

Faculty of Science and Engineering, Laurentian University, Sudbury, ON, P3E 2C6, Canada

Glycerol is a major by-product of the biodiesel industry and its transformation into value-added products is an ongoing technological challenge. Here we report on the ability of the nutritionally-versatile Pseudomonas fluorescens to synthesize copious amount of α-ketoglutarate (KG) in a glycerol medium supplemented with manganese (Mn). The enhanced production of this keto-acid was mediated by the increased activities of isocitrate dehydrogenase (ICDH)-(NAD)P dependent and aminotransaminases. At stationary phase of growth when the optimal quantity of KG was recorded, these enzymes exhibited maximal activities. Two isoforms of pyruvate carboxylase (PC) that were identified in the Mn-treated cells provided an effective route for the synthesis of oxaloacetate, a metabolite critical in the production of KG. Furthermore, the increased activities of phosphoenol pyruvate carboxylase (PEPC) and pyruvate orthophosphate dikinase (PPDK) ensured the efficacy of this KG-generating metabolic system by supplying pyruvate and ATP from the oxaloacetate synthesized by PC. Mn-exposed whole cells converted 90% of industrial glycerol into KG. This Mn-evoked metabolic network can be optimized into the economic transformation of glycerol into KG.
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Keywords bioconversion; glycerol; α-ketoglutarate; manganese; pyruvate carboxylase; metabolic networks

Citation: Azhar A. Alhasawi, Vasu D. Appanna. Manganese orchestrates a metabolic shift leading to the increased bioconversion of glycerol into α-ketoglutarate.. AIMS Bioengineering, 2017, 4(1): 12-27. doi: 10.3934/bioeng.2017.1.12


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This article has been cited by

  • 1. Azhar A. Alhasawi, Sean C. Thomas, Sujeethar Tharmalingam, Felix Legendre, Vasu D. Appanna, Isocitrate Lyase and Succinate Semialdehyde Dehydrogenase Mediate the Synthesis of α-Ketoglutarate in Pseudomonas fluorescens, Frontiers in Microbiology, 2019, 10, 10.3389/fmicb.2019.01929
  • 2. Félix Legendre, Sujeenthar Tharmalingam, Anondo Michel Bley, Alex MacLean, Vasu D. Appanna, Metabolic adaptation and NADPH homeostasis evoked by a sulfur-deficient environment in Pseudomonas fluorescens, Antonie van Leeuwenhoek, 2019, 10.1007/s10482-019-01372-7
  • 3. F. Legendre, A. MacLean, V. P. Appanna, V. D. Appanna, Biochemical pathways to α-ketoglutarate, a multi-faceted metabolite, World Journal of Microbiology and Biotechnology, 2020, 36, 8, 10.1007/s11274-020-02900-8
  • 4. Alex MacLean, Anondo Bley, Vasu D. Appanna, , Microbial and Natural Macromolecules, 2021, 101, 10.1016/B978-0-12-820084-1.00005-3

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