Shewanella oneidensis NADH Dehydrogenase Mutants Exhibit an Amino Acid Synthesis Defect
| Autor: | Michaela A. TerAvest, Kody L. Duhl |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Economics and Econometrics
020209 energy Energy Engineering and Power Technology lcsh:A 02 engineering and technology Shewanella Article Respiratory electron transport chain 0202 electrical engineering electronic engineering information engineering Shewanella oneidensis MR-1 Shewanella oneidensis TCA cycle Amino acid synthesis chemistry.chemical_classification amino acids biology Renewable Energy Sustainability and the Environment NADH dehydrogenase 021001 nanoscience & nanotechnology biology.organism_classification Amino acid Citric acid cycle Fuel Technology chemistry Biochemistry redox state biology.protein NAD+ kinase lcsh:General Works 0210 nano-technology |
| Zdroj: | Frontiers in Energy Research, Vol 7 (2019) Front Energy Res |
| ISSN: | 2296-598X |
| DOI: | 10.3389/fenrg.2019.00116 |
| Popis: | Shewanella oneidensis MR-1 is a dissimilatory metal reducing bacterium with a highly branched respiratory electron transport chain. The S. oneidensis MR-1 genome encodes four NADH dehydrogenases, any of which may be used during respiration. We previously determined that a double-knockout of two NADH dehydrogenases, Nuo and Nqr1, eliminated aerobic growth in minimal medium. However, the double-knockout strain was able to grow aerobically in rich medium. Here, we determined that amino acid supplementation rescued growth of the mutant strain in oxic minimal medium. To determine the mechanism of the growth defect, we monitored growth, metabolism, and total NAD(H) pools in S. oneidensis MR-1 and the NADH dehydrogenase knockout strain. We also used a genetically encoded redox sensing system and determined that NADH/NAD(+) was higher in the mutant strain than in the wild-type. We observed that the double-knockout strain was able to metabolize d,l-lactate and N-acetylglucosamine when supplemented with tryptone, but excreted high concentrations of pyruvate and acetate. The requirement for amino acid supplementation, combined with an apparent inability of the mutant strain to oxidize pyruvate or acetate suggests that TCA cycle activity was inhibited in the mutant strain by a high NADH/NAD(+). |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|