Effect of NaCI concentration on cadmium uptake by the halophilic alga Dunaliella salina

Abstract

The effect of NaCl concentration on cadmium uptake by DunaLiella salina was investigated. Algae were grown in the presence of 5 mg I-' cadmium at NaCl concentrations varying from 0.5 M to 4 M. The response of cell-specific growth rate, pigment content, and cadmium uptake was studied. Results show maximum cadmium uptake at NaCl concentrations between 0.5 and 1.0 M and considerably lower cadmiuni uptake at NaCl concentrations above 1.0 M. It is suggested that of the Cd species existing under the experimental conditions, the positively charged Cd", CdC1' and possibly the uncharged CdC12(aq) play a major role in cadmium uptake processes.

Microalgae – A promising tool for heavy metal remediation

“…For example, in case of the alga S. bacillaris, 2.5% salinity was optimal for Cd and 20% salinity for Cu; essentially high salt concentrations can severely limit metal binding by algae (Wilde and Benemann, 1993). D. salina showed maximum cadmium uptake when NaCl concentrations ranged between 0.5 and 1.0 M; but, at NaCl concentrations4 1.0 M, considerably less cadmium uptake occurred (Rebhun and Ben-Amotz, 1986). Wang (1987) reviewed several reports indicating that metal (Ni, Zn, Sn, Cu, and Cd) toxicity decreases as chloride or salinity increases.…”

Antagonistic effect of manganese to cadmium toxicity in the alga Dunaliella salina

“…O Inter-Research/Printed in F. R. Germany Cadmium uptake has been reported in Dunaliella (Jennings & Rainbow 1979, Rebhun & Ben-Amotz 1986, but the exact location of cadmium in the cell was not resolved. Our recent paper (Rebhun & Ben-Amotz 1986) showed that the positively charged Cd2', CdC1+ and possibly the neutral CdC12(aq) are toxic to Dunaliella.…”

“…Our recent paper (Rebhun & Ben-Amotz 1986) showed that the positively charged Cd2', CdC1+ and possibly the neutral CdC12(aq) are toxic to Dunaliella.…”

“…Cadmium has been found to exert a toxic effect on plants (Weigel 1985) and various unicellular algae such as Chlorella (Rosko & Rachlin 1975, Hart & Scaife 1977, Hart et al 1979, Gipps & Coller 1980, Rebhun & Ben-Amotz 1984, Euglena (De Filippis et al 1981, Bariaud et al 1985, &atoms (Conway & Williams 1979, Rachlin et al 1982, 1983, Dunaliella (Jennings & Rainbow 1979, Rebhun & Ben-Amotz 1986, Monochrysis and Isochrysis (Wikfors & Ukeles 1982), Isochrysis (Li 1980), and other phytoplankton (Kayser & Sperling 1980, Rabsch & Elbrachter 1980, Wolter et al 1984). …”

Use of factorial experimental design to evaluate how biotic and abiotic factors influence cadmium accumulation in the unicellular alga Dunaliella bioculata

“…Studies on the accumulation of heavy metals by these cells in culture showed that uptake depends on many different variables such as exposure time (Gnassia-Barelli & Hardstedt-Romeo 1982), other heavy metals (Gray 1974, Stary & Kratzer 1982, natural exudates (Hardstedt-Romeo & GnassiaBarelli 1980), nutrient cations such as Ca2+, ~n~ ' , ~e~+ , zn2+, ~g~+ (Braek et al 1980, Singh & Pandey 1981, salinity (Rebhun & Ben-Amotz 1986) and growth phase (Gipps & Coller 1982). However, in these toxicological O Inter-ResearchIPrinted in F. R. Germany studies, the variables were tested individually.…”