The growth response of the green alga Chlorella vulgaris to combined divalent cation exposure.
Using the growth response of the green alga Chlorella vulgaris as a model system, the effects of combinations of the environmentally active cations Cd, Co, and Cu were evaluated. The 96-h static EC50 for these cations to C. vulgaris were, respectively, 0.89 microM, 9.0 microM, and 2.8 microM, yielding a toxicity series such that Cd > Cu > Co. The cation combinations of Cd + Cu, and Cu + Co acted synergistically, while Cd + Co, and the tri-metallic combination Cd + Cu + Co resulted in antagonistic interactions. Examination of these toxic combinations at 24, 48, 72, and 96 h indicate that the cellular response is not a uniform one. Failure of energy dispersive X-ray spectrophotometric analysis to demonstrate any intracellular incorporation of these cations (except for a weak cytoplasmic Cu peak at the 8.0 KEV position) suggests that the toxic actions of these cations at EC50 concentrations are exerted at the level of the plasma membrane.
Rachlin
J W
JW
Department of Biological Sciences, Lehman College, City University of New York, West, Bronx 10468-1589.
Grosso
A
A
D002104:Cadmium / Q000633:toxicity*; D002412:Cations / Q000633:toxicity; D002708:Chlorella / Q000187:drug effects* / Q000254:growth & development; D003035:Cobalt / Q000633:toxicity*; D003300:Copper / Q000633:toxicity*; D004338:Drug Combinations; D007928:Lethal Dose 50
D002412:Cations; D004338:Drug Combinations; D002104:Cadmium; D003035:Cobalt; D003300:Copper