Hydrogen production driven by formate oxidation in Shewanella oneidensis MR-1
Shewanella oneidensis MR-1 is a potent hydrogen producer in the deficiency of exogenous electron acceptors. The electron transfer pathway for hydrogen production remains unclear, although enzymes for hydrogen production have been identified in S. oneidensis MR-1. In this study, we investigated the e...
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Published in: | Applied microbiology and biotechnology Vol. 104; no. 12; pp. 5579 - 5591 |
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Main Authors: | , , , , , , , |
Format: | Journal Article |
Language: | English |
Published: |
Berlin/Heidelberg
Springer Berlin Heidelberg
01-06-2020
Springer Springer Nature B.V |
Subjects: | |
Online Access: | Get full text |
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Summary: | Shewanella oneidensis
MR-1 is a potent hydrogen producer in the deficiency of exogenous electron acceptors. The electron transfer pathway for hydrogen production remains unclear, although enzymes for hydrogen production have been identified in
S. oneidensis
MR-1. In this study, we investigated the electron transfer pathway from formate to hydrogen, given that formate is commonly a key chemical for bacterial hydrogen production. We revealed that two formate dehydrogenases FdhA1B1C1 and FdhA2B2C2, rather than FdnGHI, played a dominant role in formate-driven hydrogen production. Menaquinone was indispensable for the electron transfer from formate to hydrogen, which excluded the presence of formate hydrogen-lyase in
S. oneidensis
MR-1. A previously proposed formate dehydrogenase subunit HydC was identified as a menaquinone-binding subunit of [FeFe] hydrogenase HydAB, and the
hydABC
operon is conserved in bacteria living in diverse environments. A formate exporter FocA and transcriptional regulator FhlA were identified for their effect on formate metabolism and hydrogen production. FhlA positively affected the metabolism of formate and hydrogen by regulating the expression of
fdhA2B2C2
,
fdnGHI
,
focA
, and
dld-II
. Overall, the electron transfer pathway deciphered in this work will facilitate the improvement of biohydrogen production by
S. oneidensis
MR-1.
Key Points
• The electron transfer pathway from formate to hydrogen in MR-1 is deciphered.
• Menaquinone is indispensable for hydrogen production.
• A cytochrome b subunit transfers electrons from menaquinone to [FeFe] hydrogenase. |
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ISSN: | 0175-7598 1432-0614 |
DOI: | 10.1007/s00253-020-10608-w |