THE INFLUENCE OF pH AND MEDIA COMPOSITION ON THE UPTAKE OF INORGANIC SELENIUM BY CHLAMYDOMONAS REINHARDTII

Riedel, Gerhardt F.; Sanders, James G.

doi:10.1897/1551-5028(1996)015<1577:tiopam>2.3.co;2

Cited by 23 publications

(39 citation statements)

References 24 publications

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“…Uptake of Se was significantly reduced by P additions in most cases but not by N additions. These observations are consistent with the results of previous studies using pure unicellular cultures [14,22]. For example, Wang and Dei [14] demonstrated that Se(IV) accumulation in both diatoms ( T. pseudonana and Skeletonema costatum ) and a green alga ( Chlorella autotrophica ) was inversely dependent on the ambient P and Si concentrations.…”

Section: Discussionsupporting

confidence: 92%

Seasonal study on the Cd, Se, and Zn uptake by natural coastal phytoplankton assemblages

Wang

Dei

Hong

2005

Enviro Toxic and Chemistry

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We conducted a seasonal study of the uptake of Cd, Se(IV), and Zn by natural phytoplankton assemblages collected from two locations in Hong Kong coastal waters. Marine phytoplankton in Port Shelter was dominated by diatoms and cyanobacteria, while phytoplankton in Tolo Harbour was dominated by dinoflagellates. The natural phytoplankton assemblages were spiked with macronutrients (N and P) and metals, and the accumulation of these metals was followed for 3 to 5 d in the laboratory. The two coastal systems were mostly P limited, with N limitation observed only during the summer in Tolo Harbour. With the additions of these macronutrients, phytoplankton responded in different ways in their accumulation of trace metals. Cadmium concentrations (normalized to chlorophyll a [chl a] concentration) increased by 25 to 38% with the simultaneous addition of N and P but were roughly constant when N alone was added. In N-limited systems, the Cd concentration increased by 25% with N addition. Concentrations of Se were reduced competitively (by 40-45%) with P addition. Zinc concentrations were reduced by 23 to 38% when both N and P were added, largely because of a major increase in biomass (biodilution). Both Cd and Zn uptake rates increased with increasing growth rates. The uptake rate of Se was not related to the growth rate because of the confounding influence of P addition. The particle concentration effect was observed only for Zn, in which the increasing chl a concentration biodiluted the Zn concentration in the phytoplankton. Overall, our results suggest that macronutrients may affect trace metal accumulation in natural phytoplankton because of their controls on cell growth, which may have implications for our understanding of trace metal dynamics in coastal ecosystems during phytoplankton blooms as well as for the prediction of trophic transfer in food chains.

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Section: Discussionsupporting

confidence: 92%

Seasonal study on the Cd, Se, and Zn uptake by natural coastal phytoplankton assemblages

Wang

Dei

Hong

2005

Enviro Toxic and Chemistry

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“…Thus, variation of metal K u values among different batches of experiments is rather small. Anionic metals [e.g., Cr(VI) and Se(IV)] are generally taken up at a slower rate, probably because of competition with major anions in seawater [28][29][30]. As found in previous studies, the uptake rate was highest for metals (e.g., Cd and Zn) that require facilitated transport in which SH-containing ligands are involved in metal binding [24].…”

Section: Metal Uptake Rate Constants In Bivalvesmentioning

confidence: 87%

Comparison of Metal Uptake Rate and Absorption Efficiency in Marine Bivalves

Wang¹

2001

Environ Toxicol Chem

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Recent studies have quantified extensively metal assimilation efficiency from ingested food sources in aquatic invertebrates. Metal absorption efficiency (alpha) from the dissolved phase is analogous to metal assimilation efficiency, but it remains poorly defined and quantified. In this study, the alpha of four trace metals [Cd, Cr(VI), Se(IV), and Zn] was determined in three species of marine bivalves (green mussel [Perna viridis], black mussel [Septifer virgatus], and clam [Ruditapes philippinarum]). Individual bivalves were first measured for their clearance rates, followed by measurements of the metal influx rate, after which the metal alpha and the uptake rate constant (Ku) were then computed. Among the four metals considered, the highest Ku and alpha were found for Zn, followed by Cd > Cr(VI) > Se(IV). The Ku values were comparable between the two mussels but were 1.8- to 3.3-fold lower in the clams. Interspecific difference in metal Ku was strongly related to, but intraspecific difference in Ku was not affected by, the bivalve's clearance rate. Interspecific difference in metal alpha was smaller than the metal Ku and was independent of the clearance rate, whereas the intraspecific difference in metal alpha correlated with the individual variations of the clearance rate. Within each bivalve species, a significant negative correlation was found between the metal alpha and the clearance rate, implying that an individual pumping a greater amount of water was coupled to a lower alpha. Significant correlation between the alpha of four metals was also documented in all three species of bivalves. Thus, metal bioavailability from the aqueous phase was directly related to the physiological conditions of the animals. Both the aqueous chemistry and the physiology of the animals can be important in affecting metal bioavailability from the dissolved phase.

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“…Because selenite may be taken up mainly through anionic transporters, it appears that the membrane permeability brought by a change in Ca 2+ concentration may be responsible for a change in Se influx. Using only one Ca 2+ concentration treatment (+1 mM Ca 2+ ), Riedel and Sanders [34] showed no significant effect of Ca 2+ on selenite uptake by the green alga Chlamydomonas reinhardtii . The influence of Ca 2+ on Zn influx may be a result of accidental uptake of Zn through the Ca channel.…”

Section: Discussionmentioning

confidence: 99%

Kinetic uptake of bioavailable cadmium, selenium, and zinc by Daphnia magna

Wang

2002

Enviro Toxic and Chemistry

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Kinetic uptake of Cd, Se(IV), and Zn by Daphnia magna from the dissolved phase was determined using radiotracer techniques in moderately hard water. The metal influx rate and distribution in the soft tissue and the exoskeleton of the daphnids as influenced by metal concentration, inorganic ligands including pH, Ca2+ and SO4(2-), and body size were quantified. When the metal concentrations were <180 nM for Cd and <769 nM for Zn, the concentration factor in daphnids increased linearly within the 12 h of exposure. At a higher concentration, apparent steady state was reached after 3 h of exposure. Cadmium and Zn distribution in the soft tissues was not affected by the total ambient concentrations, whereas Se distribution in the soft tissue decreased by 7 to 10% with increasing Se concentration from 16 to 643 nM. A linear positive power relationship was found between the influx rates of the metals and the ambient concentrations. The concentration factor for Se, however, decreased significantly with increasing Se concentration in water. The influx rate of metals was inversely related to the body size in a power function. When the pH in ambient water increased from 5.0 to 7.0, the influx rate of Cd, Se, and Zn increased by 2.9, 16.6, and 4.1 times, respectively. The influx rates of Cd, Se, and Zn decreased by 6.9, 8.7, and 4.4 times, respectively, with an increase in Ca2+ concentration from 0.6 to 5.1 mM. In contrast, the uptake rates of all three metals were not significantly affected by the SO4(2-) concentration. The majority of accumulated Se was distributed in the soft tissues after 12 h of exposure, whereas Cd and Zn were about evenly distributed in the soft tissue and exoskeleton. Any changes in pH, Ca2+, and SO4(2-) concentrations did not apparently affect their distributions in the daphnids. Our study provides important kinetic data necessary for delineating the exposure routes and for further development of the biotic ligand model in Daphnia. Using a bioenergetic-based kinetic model, we showed that the dissolved uptake is dominant for Zn accumulation (>50%). For Cd and Se, dietary exposure is dominant when the bioconcentration factors of these metals in phytoplankton are at the high end.

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THE INFLUENCE OF pH AND MEDIA COMPOSITION ON THE UPTAKE OF INORGANIC SELENIUM BY CHLAMYDOMONAS REINHARDTII

Cited by 23 publications

References 24 publications

Seasonal study on the Cd, Se, and Zn uptake by natural coastal phytoplankton assemblages

Seasonal study on the Cd, Se, and Zn uptake by natural coastal phytoplankton assemblages

Comparison of Metal Uptake Rate and Absorption Efficiency in Marine Bivalves

Kinetic uptake of bioavailable cadmium, selenium, and zinc by Daphnia magna

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