Exploring the ammonium and nitrate transport of marine phytoplankton with nutrient analogues
Radiolabelled methylamine, an ammonium analogue and chlorate, a nitrate analogue, were transported constitutely by laboratory and field populations of phytoplakton. There was no effect of light on the transport of methylamine or chlorate which is contrary to similar measurements made with /sup 15/N-NH/sub 4//sup +/ and /sup 15/N-NO/sub 3//sup -/. The discrepancy appears to result from the fact that the analogues are only transported, while /sup 15/N-NH/sub 4/ and /sup 15/N-NO/sub 3//sup -/ are both transported and assimilated. Transport of ammonium and nitrate appeared to be active; it was against typical values of algal electrochemical gradients. Influx and efflux rates of methylamine and chlorate were measured in pulse-chase experiments; efflux rates increased as intracellular pools filled and net uptake slowed after approximately one to six hours. The pulse-chase experiments indicated that methylamine and chlorate (hence ammonium and nitrate) were stored in two intracellular compartments of diatoms, probably the vacuole and cytoplasm. Laboratory and field experiments demonstrated that chlorate transport by phytoplankton was inhibited when ambient ammonium or nitrite concentrations were high.
- Research Organization:
- California Univ., San Diego (USA)
- OSTI ID:
- 7169652
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
54 ENVIRONMENTAL SCIENCES
AMMONIUM COMPOUNDS
ENVIRONMENTAL TRANSPORT
UPTAKE
NITRATES
PHYTOPLANKTON
NUTRIENTS
AQUATIC ECOSYSTEMS
BENCH-SCALE EXPERIMENTS
BIOLOGICAL MODELS
CHLORATES
CYTOPLASM
DIATOMS
EXPERIMENTAL DATA
FIELD TESTS
INHIBITION
LABELLED COMPOUNDS
METHYLAMINE
NITRITES
NITROGEN 15
TRACER TECHNIQUES
VISIBLE RADIATION
ALGAE
AMINES
AQUATIC ORGANISMS
CELL CONSTITUENTS
CHLORINE COMPOUNDS
DATA
ECOSYSTEMS
ELECTROMAGNETIC RADIATION
HALOGEN COMPOUNDS
INFORMATION
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
MASS TRANSFER
NITROGEN COMPOUNDS
NITROGEN ISOTOPES
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PLANKTON
PLANTS
RADIATIONS
STABLE ISOTOPES
TESTING
560300* - Chemicals Metabolism & Toxicology
520200 - Environment
Aquatic- Chemicals Monitoring & Transport- (-1989)