Mechanisms of inorganic-carbon acquisition in marine phytoplankton and their implications for the use of other resources

Journal Article · Sun Dec 01 00:00:00 EST 1991 · Limnology and Oceanography; (United States)

DOI:https://doi.org/10.4319/lo.1991.36.8.1701· OSTI ID:6994333

Raven, J A; Johnston, A M ^[1]

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1. Univ. of Dundee, Scotland (United Kingdom)

Most of the marine phytoplankton species for which data are available are rate saturated for photosynthesis and probably for growth with inorganic C at normal seawater concentrations; 2 of the 17 species are not saturated. Photosynthesis in these two species can probably be explained by the 17 species not saturated. Photosynthesis in these two species can probably be explained by assuming that CO{sub 2} reaches the site of its reaction with RUBISCO (ribulose bisphosphate carboxylase-oxygenase) by passive diffusion. The kinetics of CO{sub 2} fixation by intact cells are explicable by RUBISCO kinetics typical of algae, and a CO{sub 2}-saturated in vivo RUBISCO activity not more than twice the in vivo light- and inorganic-C-saturated rate of photosynthesis. For the other species, the high affinity in vivo for inorganic C could be other species, the high affinity in vivo for inorganic C could be explained by postulating active influx of inorganic C yielding a higher concentration of CO{sub 2} available to RUBISCO during steady state photosynthesis than in the medium. Although such a higher concentration of internal CO{sub 2} in cells with high affinity for inorganic C is found at low levels of external inorganic C, the situation is more equivocal at normal seawater concentrations. In theory, the occurrence of a CO{sub 2}-concentrating mechanism rather than passive CO{sub 2} entry could reduce the photon, N, Fe, Mn, and Mo costs of growth, but increase the Zn and Se costs. Thus far, data on costs are available only for photons and N; these data generally agree with the predicted lower costs for cells with high affinity for inorganic C.

• OSTI ID: 6994333
• Journal Information: Limnology and Oceanography; (United States), Vol. 36:8; ISSN 0024-3590
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
29 ENERGY PLANNING
POLICY AND ECONOMY
CARBON DIOXIDE
ECOLOGICAL CONCENTRATION
PHYTOPLANKTON
CARBON DIOXIDE FIXATION
SEAS
CARBON CYCLE
CARBON SINKS
IRON
MANGANESE
MOLYBDENUM
NICKEL
NUTRIENTS
PHOTONS
PHOTOSYNTHESIS
PRODUCTIVITY
SELENIUM
ZINC
AQUATIC ORGANISMS
BOSONS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
ELEMENTARY PARTICLES
ELEMENTS
MASSLESS PARTICLES
METALS
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PLANKTON
PLANTS
SEMIMETALS
SINKS
SURFACE WATERS
SYNTHESIS
TRANSITION ELEMENTS
540320* - Environment
Aquatic- Chemicals Monitoring & Transport- (1990-)
560300 - Chemicals Metabolism & Toxicology
290301 - Energy Planning & Policy- Environment
Health
& Safety- Regional & Global Environmental Aspects- (1992-)