Promoting photo-fermentative hydrogen production performance by substituting the rnf promoter in Rhodobacter capsulatus
| Autor: | Thomas J. Lie, Xiaojing Zheng, Honghui Yang, Hongyu Ma, Wei Yan |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Rhodobacter
biology Renewable Energy Sustainability and the Environment Chemistry Mutant Energy Engineering and Power Technology Nitrogenase Promoter 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics biology.organism_classification 01 natural sciences 0104 chemical sciences Cell biology Fuel Technology Transcription (biology) Fermentative hydrogen production 0210 nano-technology Gene Bacteria |
| Zdroj: | International Journal of Hydrogen Energy. 46:3742-3752 |
| ISSN: | 0360-3199 |
| DOI: | 10.1016/j.ijhydene.2020.10.270 |
| Popis: | The Rnf (Rhodobacter nitrogen fixation) complex encoded by rnfABCDGEH genes is a crucial enzyme for the functioning of nitrogenase. In this work, we studied the effect of Rnf complex expression level on hydrogen production in the hydrogen-producing bacterium Rhodobacter capsulatus SB 1003 by expressing rnf genes with three autologous promoters. Substitution of the rnf promoter with that of pucB resulted in a 1.59-fold increase in rnf transcription level and 1.3-fold increase in nitrogenase activity. Under various test conditions, maximum H2 yields and production rates were increased by 12.4%–24.7% and 6.5%–22.9%, respectively. There was a further increase in H2 production when the Prnf::PpucB::rnf fusion construct was expressed in a background strain with both the alternative Fe nitrogenase and the Mo nitrogenase co-expressed. The results demonstrate that the Rnf complex catalyzes a rate-limiting step in photo-fermentative H2 production. The mutants with overexpressed Rnf complex are more competitive than naturally isolated strains under low light condition or in scale-up bioreactors. |
| Databáze: | OpenAIRE |
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