Effect of cadmium(II), chromium(VI), and arsenic(V) on long-term viability- and growth-inhibition assays using Vibrio fischeri marine bacteria.
As a complement to previous results obtained using the standard Microtox acute-toxicity test, which is based on measuring the rapid decrease of bioluminescence (5 to 30 minutes of exposure) in Vibrio fischeri bacteria in the presence of toxicants, the long-term effects of Cd(II), Cr(VI), and As(V) were studied on growth rate and viability assays of the same bacteria adapted to longer-lasting cultures, i.e., 48 or 72 hours instead of 5 or 30 minutes. Effects on viability or growth, as studied by establishing dose- and time-response curves, confirmed that these poisonous chemicals were not particularly toxic to these bacteria. Nevertheless, in the case of Cr(VI), the viability-inhibition assay appeared to be more sensitive than the Microtox acute-toxicity test. Interestingly, it was possible to observe a clear hormesis phenomenon, especially for Cd(II), under the conditions of both viability- and growth-inhibition assays.
Fulladosa
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Department of Chemical Engineering, University of Girona, Avda. Lluís Santaló, s/n, Girona, 17071, Spain,
Murat
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JC
Villaescusa
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I
D048908:Aliivibrio fischeri / Q000187:drug effects* / Q000254:growth & development / Q000648:ultrastructure; D001151:Arsenic / Q000494:pharmacology*; D002104:Cadmium / Q000494:pharmacology*; D002857:Chromium / Q000494:pharmacology*; D020128:Inhibitory Concentration 50; D008855:Microscopy, Electron, Scanning; D018675:Toxicity Tests / Q000379:methods*
D002104:Cadmium; D002857:Chromium; C074702:chromium hexavalent ion; D001151:Arsenic