Effect of Cadmium(II), Chromium(VI), and Arsenic(V) on Long-Term Viability- and Growth-Inhibition Assays Using Vibrio fischeri Marine Bacteria

Abstract

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.

Toxicity of Some Pesticides, Heavy Metals and Their Mixtures to Vibrio fischeri Bacteria and Daphnia magna: Comparative Study

“…In the Microtox ® assay, antagonism dominated the toxicity of heavy metal mixtures, while synergism was obtained for the binary mixtures of pesticides (Table 5). Our results agreed with those reported by Fulladosa et al (2005) regarding to the antagonistic effect of Cd-Pb and Cu-Pb mixtures against Vibrio fischeri bacteria.…”

“…ISSN 2157-6076 2015 Cd and Pb reported by different investigators, compared with our results. It seems that our result for Cd (4.47 mg/L) was very low as compared with those reported by Codina et al (1993), Newman and McCloskey (1996), Mowat and Bundy (2002) and Fulladosa et al (2005); which respectively equaled to 34.70, 21.90, 59.30 and 10.90 mg/L. For Cu and Pb, the opposite was obtained where our EC50 values (2.84 and 5.83 mg/L, respectively) were generally higher than those reported by other investigators (Table 6).…”

“…In the present study, all types of interaction were obtained in the Daphnia bioassay, while additive effect was not counted in the Microtox ® assay. The extent of deviation from a simple additive effect generally depends on (1) the ISSN 2157-6076 2015 measured parameter, (2) the chemical nature of toxicants and (3) the relative contribution of each toxicant to the toxicity of the mixture (Fulladosa et al, 2005). Furthermore, variation in sensitivity of D. magna and V. fischeri to the tested toxicants should be taken into account.…”

Sensitivity of bacterial vs. acute Daphnia magna toxicity tests to metals

“…A clear hormesis phenomenon caused by the presence of Cd(II) in low concentrations, under the conditions of both viability and growth-inhibition assays with V. fischeri has been already reported [37].…”

Optimal conditions for stability of photoemission and freeze drying of two luminescent bacteria for use in a biosensor

“…In a study of the effects of As(III) and As(V) on V. fischeri, chemical speciation was found to be correlated with toxicity [13]; this could explain why it was difficult to obtain a clear EC50. In the same study, a correlation was observed between toxicity and pH; i.e., changes in pH of the pollutant solutions resulted in improvement or reduction of the EC50.…”