Ammonium and nitrate uptake by the marine macrophytes Hypnea musciformis (Rhodophyta) and Macrocystis pyrifera (phaeophyta)

Journal Article · Sun Jan 01 04:00:00 EST 1978 · J. Phycol.; (United States)

DOI:https://doi.org/10.1111/j.1529-8817.1978.tb00305.x· OSTI ID:6642207

Haines, K C ^[1]; Wheeler, P A

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1. Univ. of Texas Marine Science Inst., St. Croix, US Virgin Islands

NH/sub 4//sup +/ and NO/sub 3//sup -/ uptake were measured by continuous sampling with an autoanalyzer. For Hypnea musciformis (Wulfen) Lamouroux, NO/sub 3//sup -/ uptake followed saturable kinetics (K/sub s/ = 4.9 ..mu..g-at N.l/sup -1/, V/sub max/ = 2.85 ..mu..g-at N-g(wet)/sup -1/.h/sup -1/). The ammonium uptake data fit a truncated hyperbola, i.e., saturation was not reached at the concentrations used, NO/sub 3//sup -/ uptake was reduced one-half in the presence of NH/sub 4//sup +/, but presence of NO/sub 3//sup -/ had no effect on NH/sub 4//sup +/ uptake. Darkness reduced both NO/sub 3//sup -/ and NH/sub 4//sup +/ uptake by one-third to one-half. For Macrocystis pyrifera (L.) C. Agardh. NO/sub 3//sup -/ uptake followed saturable kinetics; K/sub s/ = 13.1 ..mu..g-at N.l/sup -1/, V/sub max/ = 3.05 ..mu..g-at N.g(wet)/sup -1/.h/sup -1/. NH/sub 4//sup +/ uptake showed saturable kinetics at concentrations below 22 ..mu..g-at N.l/sup -1/(K/sub s/ = 5.3 ..mu..g-at N.l/sup -1/, V/sub max/ = 2.38 ..mu..g-at N g(wet)/sup -1/.h/sup -1/); at higher concentrations uptake increased linearly with concentration. NO/sub 3//sup -/ and NH/sub 4//sup +/ were taken up simultaneously; presence of one form did not affect uptake of the other.

• OSTI ID: 6642207
• Journal Information: J. Phycol.; (United States), Journal Name: J. Phycol.; (United States) Vol. 14; ISSN JPYLA
• Country of Publication: United States
• Language: English

Related Subjects

520100 -- Environment
Aquatic-- Basic Studies-- (-1989)
54 ENVIRONMENTAL SCIENCES
550500 -- Metabolism
560303* -- Chemicals Metabolism & Toxicology-- Plants-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMMONIUM COMPOUNDS
ANIONS
AQUATIC ECOSYSTEMS
BIOCHEMICAL REACTION KINETICS
CATIONS
CHARGED PARTICLES
ECOSYSTEMS
FRESH WATER
HYDROGEN COMPOUNDS
ION MOBILITY
IONS
KINETICS
METABOLISM
MOBILITY
NITRATES
NITROGEN COMPOUNDS
OXYGEN COMPOUNDS
PARTICLE MOBILITY
PLANTS
QUANTITY RATIO
REACTION KINETICS
SAMPLING
SATURATION
SENSITIVITY
TUBERS
UPTAKE
WATER