| Registro completo |
| Provedor de dados: |
ArchiMer
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| País: |
France
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| Título: |
Binding of Hg by bacterial extracellular polysaccharide: a possible role in Hg tolerance
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| Autores: |
Cruz, Kimberly
Guezennec, Jean
Barkay, Tamar
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| Data: |
2017-07
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| Ano: |
2017
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| Palavras-chave: |
Mercury
Bacteria
Sorption
Tolerance
Exocellular polysaccharides
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| Resumo: |
Bacteria employ adaptive mechanisms of mercury (Hg) tolerance to survive in environments containing elevated Hg concentrations. The potential of extracellular polysaccharides (EPS) production by bacteria as a mechanism of Hg tolerance has not been previously investigated. The objectives of this study were to determine if bacterial EPS sorb Hg, and if so does sorption provide protection against Hg toxicity. Purified EPS with different chemical compositions produced by bacterial isolates from microbial mats in French Polynesian atolls and deep-sea hydrothermal vents were assessed for Hg sorption. The data showed that EPS sorbed up to 82% of Hg from solution, that this sorption was dependent on EPS composition, and that sorption was a saturable mechanism. Hg uptake capacities ranged from 0.005 to 0.454 mmol Hg/g for the different EPS. To determine if EPS production could alter bacterial Hg tolerance, Escherichia coli K-12 strains and their EPS defective mutants were tested by the disc inhibition assay. Mercury inhibited growth in a dose-dependent manner with wild-type strains having smaller (~1 mm), but statistically significant, zones of inhibition than various mutants and this difference was related to a 2-fold decline in the amount of EPS produced by the mutants relative to cell biomass. These experiments identified colanic acid and hexosamine as Hg-binding moieties in EPS. Together these data indicate that binding of Hg to EPS affords a low level of resistance to the producing bacteria.
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| Tipo: |
Text
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| Idioma: |
Inglês
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| Identificador: |
http://archimer.ifremer.fr/doc/00382/49348/49786.pdf
DOI:10.1007/s00253-017-8239-z
http://archimer.ifremer.fr/doc/00382/49348/
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| Editor: |
Springer
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| Formato: |
application/pdf
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| Fonte: |
Applied Microbiology And Biotechnology (0175-7598) (Springer), 2017-07 , Vol. 101 , N. 13 , P. 5493-5503
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| Direitos: |
Springer-Verlag Berlin Heidelberg 2017
info:eu-repo/semantics/openAccess
restricted use
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