Malic Enzyme Facilitates d-Lactate Production through Increased Pyruvate Supply during Anoxic Dark Fermentation in Synechocystis sp. PCC 6803

• 秀瀨, 涼太

• Matsuda, Mami

• Osanai, Takashi

• 蓮沼, 誠久

• 近藤, 昭彦

抄録

d-Lactate is one of the most valuable compounds for manufacturing biobased polymers. Here, we have investigated the significance of endogenous malate dehydrogenase (decarboxylating) (malic enzyme, ME), which catalyzes the oxidative decarboxylation of malate to pyruvate, in d-lactate biosynthesis in the cyanobacterium Synechocystis sp. PCC6803. d-Lactate levels were increased by 2-fold in ME-overexpressing strains, while levels in ME-deficient strains were almost equivalent to those in the host strain. Dynamic metabolomics revealed that overexpression of ME led to increased turnover rates in malate and pyruvate metabolism; in contrast, deletion of ME resulted in increased pool sizes of glycolytic intermediates, probably due to sequential feedback inhibition, initially triggered by malate accumulation. Finally, both the loss of the acetate kinase gene and overexpression of endogenous d-lactate dehydrogenase, concurrent with ME overexpression, resulted in the highest production of d-lactate (26.6 g/L) with an initial cell concentration of 75 g-DCW/L after 72 h fermentation.

収録刊行物

• ACS Synthetic Biology

  ACS Synthetic Biology 9 (2), 2020-01-31

  American Chemical Society

キーワード

• cyanobacteria
• d-lactate
• malate dehydrogenase (decarboxylating)
• metabolomics
• Synechocystis sp. PCC6803

詳細情報

• CRID: 1050856995322926848
• NII論文ID: 120006796500
• ISSN: 21615063
• HANDLE: 20.500.14094/90006763
• 本文言語コード: en
• 資料種別: journal article
• データソース種別:
  • IRDB
  • CiNii Articles