Toxicity of zinc in three microbial test systems

Ghosh, Sandip; Doctor, P. B.; Kulkami, P. K.

doi:10.1002/(sici)1098-2256(1996)11:1<13::aid-tox3>3.0.co;2-c

Cited by 19 publications

(9 citation statements)

References 10 publications

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“…The Microtox and P. phosphoreum bioassays use two strains of the same bacterial species, Photobacterium phosphoreum. Strain 11177, used in the Microtox bioassay, is highly sensitive to contaminants (http://www.azurenv.com) including metals (Codina et al, 1993;Ghosh et al, 1996). Indeed, the toxicity response of the P. phosphoreum Microtox bioassay to Cr, Mn, and Zn contrasted with the lack of effect of the same metals with similar speciation on the wild strain of P. phosphoreum.…”

Section: Discussionmentioning

confidence: 99%

“…Therefore, assuming that toxicity is related to metal speciation, a toxicity assessment of a freshwater or marine sample might be biased when using the Microtox bioassay, which has a NaCl-based medium (Villaescusa et al, 1996). This bioassay is known to overestimate the toxicity of metals more than do seawater-based nonmicrobial bioassays (Becerro et al, 1995;Ghosh et al, 1996). This could be because of the difference in speciation (i.e., fewer complexes in the Microtox bioassay medium), but it also could be a result of the inherent sensitivity of Microtox cells to metals.…”

Section: Discussionmentioning

confidence: 99%

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Chemical speciation and toxicity of metals assessed by three bioluminescence‐based assays using marine organisms

Deheyn

Bencheikh-Latmani

Latz

2004

Environmental Toxicology

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ABSTRACT:Metal toxicity is a function of the biology of the target organism and the chemical speciation of the metal. The toxicity of 11 metals was assessed with three cell-based bioassays based on marine organisms: the bacterium Photobacterium phosphoreum of the Microtoxா bioassay, an environmental strain of P. phosphoreum, and photocytes isolated from the brittlestar Ophiopsila californica. Metal speciation was calculated for three commonly used media: NaCl-based Microtoxா bioassay medium, artificial seawater glycerol, and artificial seawater. Decreased bioluminescence was considered a proxy for cell toxicity. In all three assays the elements Cd and Hg exhibited similar speciation as well as similar toxicity profiles. The element Cu was toxic in all three assays despite different metal speciation for the P. phosphoreum bioassay. The element Ag was toxic to both bacterial strains but not to photocytes despite a similar chemical speciation for all three assays. In general, the Microtoxா bioassay was sensitive to all metals (except Pb), whereas the photocytes were the least sensitive to the metals. The heightened response of the Microtoxா bioassay probably resulted from a combination of the limited complexing power of the medium and the greater sensitivity of the bacterial strain.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Chemical speciation and toxicity of metals assessed by three bioluminescence‐based assays using marine organisms

Deheyn

Bencheikh-Latmani

Latz

2004

Environmental Toxicology

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“…The precipitation mechanisms mentioned above are likely to protect intact microbenthic assemblages. However, when used for short-term toxicity tests, effect levels were not only in the same range as for bacterial single species toxicity tests (Gosh et al 1996) but were also suitable to detect a shift in community tolerance at much lower levels of long-term zinc exposure. It can be concluded that an in situ concentration of about 1 µM zinc represents a threshold level.…”

Section: Bacterial Thymidine Incorporationmentioning

confidence: 99%

Induced Metal Tolerance in Microbenthic Communities from Three Lowland Rivers with Different Metal Loads

Lehmann

Tubbing

Admiraal

1999

Arch. Environ. Contam. Toxicol.

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The response of microbenthic communities to sustained metal stress was studied in three lowland rivers with different levels of pollution. Tolerance against zinc and cadmium was determined in short-term toxicity tests with microbenthic assemblages colonizing glass discs. Photosynthetic activity served as an endpoint in tests for algae, whereas for bacteria thymidine incorporation was determined. For bacterial assemblages from unpolluted locations, EC50 values in short-term tests ranged between 6.7 and 56.2 &mgr;M zinc, and 8.7 and 25.5 &mgr;M cadmium, respectively. Bacterial assemblages from the two most polluted sites were significantly more tolerant for zinc (EC50: 994 &mgr;M and >1,000 &mgr;M) and cadmium (EC50: 218 &mgr;M and 154 &mgr;M). Results indicated a shift in community composition toward pollution-adapted organisms when a threshold concentration of 1 &mgr;M zinc is exceeded. Although an increasing community tolerance was also indicated for algae, EC50 values for microbenthic algae from all sites exceeded in most cases the highest metal concentrations tested (Zn: 1,000 &mgr;M; Cd: 320 &mgr;M). Since species composition of algal assemblages was found to change at much lower metal levels, it is concluded that short-term toxicity tests measuring photosynthesis inhibition do not reflect well the long-term effects of these metals. Toxic effects of metals on both algal and bacterial assemblages are attenuated by precipitation and complexing capacities of the biofilm.

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“…The toxicological studies need for simple, inexpensive, rapid and sensitive test in order to screen an increasing number of chemicals and assess their acute and chronic effects (Fargasová, 1994;Ghosh et al, 1996;Radix et al, 2000). Bacteria are considered test organisms that offer good response to these necessity (Ghosh et al 1996).…”

Section: Afb 1 Effects On Vibrio Fischerimentioning

confidence: 99%