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| Status |
Public on Dec 31, 2024 |
| Title |
Low levels of nitrate rather than high carbon-nitrogen ratios induce Dissimilatory Nitrate Reduction to Ammonia (DNRA) in Geobacter lovleyi SZ. |
| Organism |
Trichlorobacter lovleyi |
| Experiment type |
Expression profiling by high throughput sequencing
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| Summary |
N retention in soils can be stimulated by microorganisms carrying out dissimilatory reduction of nitrate to ammonia (DNRA), a respiratory activity that converts nitrate and/or nitrite to ammonia. Geobacter lovleyi has recently being recognized as a key driver of DNRA, providing a model to investigate the environmental signals that promote nitrate ammonification. Here we show that low nitrate concentrations (5mM) induce DNRA in G. lovleyi independently of the concentration of the electron donor, thus challenging the prevailing view that high carbon-to-nitrogen (C/N) ratio triggers this process. The nitrate transcriptome revealed a complex metabolic network of periplasmic (Nap) and cytoplasmic (Nar) nitrate reductase systems for the reduction of nitrate to nitrite. The transcriptome also included a canonical (NrfA-1), two Geobacter-specific nitrite reductases (NrfA-2 and NrfA-3) and a membrane-bound NrfH cytochrome, which electronically connects NrfA to the menaquinone pool. Flagellar motility and chemotaxis proteins were also among the most upregulated genes in the nitrate cultures, consistent with an adaptive response that allows Geobacter cells to sense and access the limited supply of nitrate in anaerobic zones of the soils and sediments. This is the first demonstration of the ability of the bacteria to use DNRA pathway under nitrate limiting conditions independently of the C/N ratio. G. lovleyi provides a model for study DNRA process and it is a good candidate that could contribute in the retention of nitrogen in soils leading to efficient use of nitrogen containing fertilizers and preventing nitrate leaching.
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| Overall design |
We extracted total RNA from exponential phase of growth in Geobacter lovleyi SZ when growth with or without 5 mM sodium nitrate.
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| Contributor(s) |
Tabares M, Reguera G |
| Citation missing |
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| |
| Submission date |
Jan 13, 2021 |
| Last update date |
Dec 31, 2024 |
| Contact name |
MARCELA TABARES |
| Organization name |
MICHIGAN STATE UNIVERSITY
|
| Department |
MMG
|
| Lab |
REGUERA LAB
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| Street address |
567 WILSON RD
|
| City |
EAST LANSING |
| State/province |
MI |
| ZIP/Postal code |
48823 |
| Country |
USA |
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| Platforms (1) |
| GPL29599 |
Illumina HiSeq 2000 (Geobacter lovleyi) |
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| Samples (6)
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| Relations |
| BioProject |
PRJNA691925 |
| SRA |
SRP301618 |
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