| Autor: |
Kazuo Kakii, Mitsuo Kuriyama, Ma.Lourdes B. Buelva |
| Rok vydání: |
1995 |
| Předmět: |
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| Zdroj: |
Journal of Fermentation and Bioengineering. 79:136-140 |
| ISSN: |
0922-338X |
| DOI: |
10.1016/0922-338x(95)94080-b |
| Popis: |
A Hg 2+ -resistant Pseudomonas which can utilize glycine as a sole carbon and nitrogen source was isolated from a municipal sewage treatment plant, and the toxicity of Hg 2+ in the presence of halide ions was examined. In glycine medium without halide ions, bacterial growth was scarcely influenced even at an initial Hg 2+ concentration of 25 μM. The viable cell count decreased when adsorbed Hg 2+ was more than 300 μmol·g-cell −1 . The toxicity of Hg 2+ was enhanced when the halide ion concentration was such that the [HgX 2 ] 0 complex ( X =Br − or I − ) in the solution became dominant. In the presence of [HgBr 2 ] 0 complex, complete growth inhibition of unacclimatized cells was observed at 2–3 μM Hg 2+ . A sudden decrease in the viable cell count was evident when adsorbed Hg 2+ was more than 15 μmol·g-cell −1 . Growth of the isolate pre-incubated in glycine medium containing 25 μM Hg 2+ (acclimatized cells) was also inhibited completely at 10 μM Hg 2+ in the presence of Br − . The adsorption and toxicity of Hg 2+ decreased with increasing halide ion concentration in which [HgBr 3 ] − or [HgBr 4 ] 2− complexes exist dominantly. These results indicate that toxicity of Hg 2+ was enhanced by the formation of [HgX 2 ] 0 complex and was not governed by the amount of Hg 2+ adsorbed to the cells. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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