Exploring the ammonium and nitrate transport of marine phytoplankton with nutrient analogues

Thesis/Dissertation · Mon Dec 31 23:00:00 EST 1984

OSTI ID:7169652

Balch, W M

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
• Country of Publication: United States
• Language: English

Related Subjects

520200 -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALGAE
AMINES
AMMONIUM COMPOUNDS
AQUATIC ECOSYSTEMS
AQUATIC ORGANISMS
BENCH-SCALE EXPERIMENTS
BIOLOGICAL MODELS
CELL CONSTITUENTS
CHLORATES
CHLORINE COMPOUNDS
CYTOPLASM
DATA
DIATOMS
ECOSYSTEMS
ELECTROMAGNETIC RADIATION
ENVIRONMENTAL TRANSPORT
EXPERIMENTAL DATA
FIELD TESTS
HALOGEN COMPOUNDS
INFORMATION
INHIBITION
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
MASS TRANSFER
METHYLAMINE
NITRATES
NITRITES
NITROGEN 15
NITROGEN COMPOUNDS
NITROGEN ISOTOPES
NUCLEI
NUMERICAL DATA
NUTRIENTS
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PHYTOPLANKTON
PLANKTON
PLANTS
RADIATIONS
STABLE ISOTOPES
TESTING
TRACER TECHNIQUES
UPTAKE
VISIBLE RADIATION