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Updated: May 27, 2026
08:05
Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O
Published on: October 7, 2020
Bacterial nitrate assimilation: gene distribution and regulation
Víctor M Luque-Almagro1, Andrew J Gates, Conrado Moreno-Vivián
1Departamento de Bioquímica y Biología Molecular, Universidad de Córdoba, Edificio Severo Ochoa, 1a planta, Campus de Rabanales, Córdoba, 14071, Spain.
Biochemical Society Transactions
|November 23, 2011
Summary
Heterotrophic bacteria widely possess systems for nitrate assimilation, challenging previous assumptions about their nitrogen metabolism. Regulation of this process involves ammonia repression and specific nitrate induction, varying across species.
Area of Science:
- Microbiology
- Biogeochemistry
- Molecular Biology
Background:
- Nitrate is crucial for phytoplankton nutrition but less studied in heterotrophic bacteria.
- Heterotrophic bacteria were traditionally viewed primarily as decomposers of organic nitrogen.
- Previous knowledge indicated some, but not all, heterotrophic bacteria could use nitrate.
Purpose of the Study:
- To investigate the prevalence of nitrate assimilation pathways in heterotrophic bacteria.
- To understand the regulation of nitrate assimilation in these organisms.
- To compare nitrate assimilation regulation in heterotrophs with other bacteria.
Main Methods:
- Analysis of available prokaryotic genome sequences.
- Review of existing literature on bacterial nitrate assimilation.
- Comparative genomics of nitrate assimilation (Nas) systems.
Main Results:
- Assimilatory nitrate reductase (Nas) systems are phylogenetically widespread in bacterial and archaeal heterotrophs.
- Genome data suggests broader utilization of nitrate by heterotrophic bacteria than previously thought.
- Regulation in Gram-negative bacteria involves ammonia repression (Ntr system) and nitrate/nitrite induction.
Conclusions:
- Heterotrophic bacteria possess widespread systems for nitrate assimilation.
- Nitrate assimilation regulation in heterotrophs is complex, involving dual control mechanisms.
- Further research is needed on the variability of nitrate/nitrite-specific control in different organisms.
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