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Doubling the catabolic reducing power (NADH) output of Escherichia coli fermentation for production of reduced products
Author(s) -
Zhou Shengde,
Iverson A. G.,
Grayburn W. S.
Publication year - 2009
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1002/btpr.302
Subject(s) - fermentation , escherichia coli , operon , biochemistry , catabolism , anaerobic exercise , chemistry , pyruvate dehydrogenase complex , formate , dehydrogenase , biology , metabolism , enzyme , catalysis , gene , physiology
Homofermentative production of reduced products requires additional reducing power output (NADH) from glucose catabolism. Anaerobic expression of the pyruvate dehydrogenase complex (PDH, encoded by aceEF‐lpd, a normal aerobic operon) is able to provide the additional NADH required for production of reduced products in Escherichia coli fermentation. The multiple promoters (pflB p (1–7)) of pyruvate formate lyase (pflB) were evaluated for anaerobic expression of the aceEF‐lpd operon. Four chromosomal constructs, pflB p (1–7)‐aceEF‐lpd, pflB p (1–6)‐aceEF‐lpd, pflB p (6,7)‐aceEF‐lpd, and pflB p 6‐aceEF‐lpd efficiently expressed the PDH complex in anaerobically grown cells. Doubling the reducing power output was achieved when glucose was oxidized to acetyl‐CoA through glycolysis and pyruvate oxidation by the anaerobically expressed PDH complex (glucose →2 acetyl‐CoA + 4 NADH). This additional reducing power output can be used for production of reduced products in anaerobic E. coli fermentation. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010