NAA for studying detoxification of Cr and Hg by Arthrobacter globiformis 151B
| Autor: | Sergey S. Pavlov, Peter Bode, I. G. Murusidze, L. M. Mosulishvili, N. Tsibakhashvili, Marina Frontasyeva, Th. G. van Meerten, Inga Zinicovscaia, E. I. Kirkesali |
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| Rok vydání: | 2010 |
| Předmět: |
Chemistry
Magnesium Health Toxicology and Mutagenesis Sodium Potassium Radiochemistry Public Health Environmental and Occupational Health chemistry.chemical_element Manganese Zinc Pollution Analytical Chemistry Mercury (element) Chromium Nuclear Energy and Engineering Radiology Nuclear Medicine and imaging Spectroscopy Arsenic |
| Zdroj: | Journal of Radioanalytical and Nuclear Chemistry. 286:533-537 |
| ISSN: | 1588-2780 0236-5731 |
| DOI: | 10.1007/s10967-010-0815-y |
| Popis: | Instrumental neutron activation analysis was used to study accumulation of Hg(II) and Cr(VI) ions in Arthrobacter globiformis 151B, a gram-positive, Cr(VI)-reducer aerobic bacterium isolated from basalt sample taken from the most polluted region in the Republic of Georgia (Kazreti). Experiments were focused on (1) accumulation of Hg(II) in bacterial cells; (2) accumulation of Cr(VI) in A. globiformis 151B in the presence of Hg(II) and (3) effects of Hg(II) and mixture of Cr(VI)–Hg(II) on the elemental composition of bacteria. It was shown that this bacterial strain possesses uptake mechanisms by which mercury toxicity can be reduced in environment and that accumulation of Cr(VI) in A. globiformis 151B is much higher in the presence of Hg(II) ions. Accumulation of Hg(II), similar to the Cr(VI) accumulation, follows well the Lengmuir–Freundlich model. NAA measurements showed increased content of Fe in bacteria under Hg and Cr action, suggesting that Fe-containing biomolecules play a decisive role in detoxifying of heavy metals by A. globiformis 151B. A concentration of 5000 μg/L of Hg(II) was found to be critical for A. globiformis 151B. At this concentration of Hg(II) the concentrations of both essential (Na, Mg, Al, Cl, K, Mn, Zn) and some non-essential elements (Rb, Sb, Sc, As) changed drastically along with a decrease of the biomass of bacteria by a factor of two. One may assume that under this high exposure to Hg(II) the structure of the bacterial cell wall was destroyed. |
| Databáze: | OpenAIRE |
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