Separating the influx and efflux components of net uptake of NO sub 3 sup - and NH sub 4 sup + with the use of isotopic fractional data
Transport processes are central to the life of organisms. It is important to dissect net uptake of metabolites and evaluate its components (influx and efflux). Results of our study have shown that our method, based on isotopic fractionation, is successful in separating the impact of changes in influx vs efflux on changes in net uptake of nitrate and that there is a high probability that the method will be equally successful with ammonium uptake. The methodology is applicable to steady state conditions unlike previous methods which involve the use of {sup 15}N or {sup 13}N labeled material or {sup 14}C labeled analogs. These previous methods require short term measurements, the shorter, the more accurate. The isotopic fractionation methodology will be applicable to steady state experiments with other nutrients containing atoms whose stable isotope abundance is measurable at the level of precision necessary for determination of overall isotopic fractionation factors (e.g., C{prime}, N, O, S). 33 refs., 3 figs., 2 tabs.
- Research Organization:
- Washington Univ., St. Louis, MO (USA)
- Sponsoring Organization:
- DOE/ER
- DOE Contract Number:
- FG02-87ER13765
- OSTI ID:
- 5606476
- Report Number(s):
- DOE/ER/13765-1; ON: DE90001200
- Country of Publication:
- United States
- Language:
- English
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