Related Experiment Video
Updated: Jul 6, 2026

Workflow Based on the Combination of Isotopic Tracer Experiments to Investigate Microbial Metabolism of Multiple Nutrient Sources
Published on: January 22, 2018
Nitrogen source influences natural abundance (15)N of Escherichia coli
Jessica G Collins1, Paul Dijkstra, Stephen C Hart
1Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, USA. Jessica.Collins@nau.edu
Abstract:
Escherichia coli cells were forced to mineralize or assimilate nitrogen in vitro by manipulating substrate carbon and nitrogen availability. When grown on an organic nitrogen source, E. coli cells released NH(4)(+) and were enriched in (15)N relative to the nitrogen source (1.6-3.1 per thousand). However, when cells were grown on an inorganic nitrogen source, the biomass was depleted (6.1-9.1 per thousand) relative to the source. By measuring (15)N enrichment of microorganisms relative to nitrogen pools, ecosystem ecologists may be able to determine if microorganisms are assimilating or mineralizing nitrogen.
More Related Videos
Related Concept Videos
Stringent Response in E. coli
Overview of Nitrogen Metabolism
The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen (N2) from the air, but this nitrogen...
The Nitrogen Cycle
Inorganic Nitrogen Assimilation
Other Nuclides: 31P, 19F, 15N NMR
While fluorine-19 and phosphorous-31 have high natural abundances (100%) and positive gyromagnetic ratios, nitrogen-15 has a low natural abundance and a negative gyromagnetic ratio. However, nitrogen-15 is still preferred over nitrogen-14 (which has a high...
Evolution of New Traits in Microbes

