Samenvatting
Cupriavidus metallidurans strains contain many genes involved in the resistance and processing of heavy
metals, which are very well studied and characterized. In addition, studies at SCK•CEN underscored the
rapid evolution of C. metallidurans strains towards significantly increased metal resistance, particularly for
silver. Our objective is to understand the molecular mechanisms of this increased resistance to silver.
C. metallidurans strains including type strain CH34, its plasmidless derivatives AE104 and NA4, isolated
from a silver-sanitized drinking water system, were grown in toxic levels of silver to obtain silver-resistant
mutants. The latter were characterized in detail via re-sequencing, oligonucleotide microarrays, RNA-seq
and deletion and complementation analyses.
Our data indicate that C. metallidurans is able to adapt rapidly to toxic silver concentrations. Silver-resistant
mutants were obtained from different strains, even from strains cured from the main mega-plasmid encoded
metal resistance determinants, indicating that the canonical efflux mechanisms are not involved. Wholegenome
expression profiling in non-selective growth conditions showed that only a few genes are commonly
up-regulated in all obtained silver-resistant mutants and some of them are downregulated in the absence of
a two-component system. In addition, deletion mutants and plasmid-based complementation confirmed that
a two-component regulatory system and two genes coding for small periplasmic proteins play a central role.
These results represent a previously uncharacterized molecular mechanism for metal/silver resistance.
metals, which are very well studied and characterized. In addition, studies at SCK•CEN underscored the
rapid evolution of C. metallidurans strains towards significantly increased metal resistance, particularly for
silver. Our objective is to understand the molecular mechanisms of this increased resistance to silver.
C. metallidurans strains including type strain CH34, its plasmidless derivatives AE104 and NA4, isolated
from a silver-sanitized drinking water system, were grown in toxic levels of silver to obtain silver-resistant
mutants. The latter were characterized in detail via re-sequencing, oligonucleotide microarrays, RNA-seq
and deletion and complementation analyses.
Our data indicate that C. metallidurans is able to adapt rapidly to toxic silver concentrations. Silver-resistant
mutants were obtained from different strains, even from strains cured from the main mega-plasmid encoded
metal resistance determinants, indicating that the canonical efflux mechanisms are not involved. Wholegenome
expression profiling in non-selective growth conditions showed that only a few genes are commonly
up-regulated in all obtained silver-resistant mutants and some of them are downregulated in the absence of
a two-component system. In addition, deletion mutants and plasmid-based complementation confirmed that
a two-component regulatory system and two genes coding for small periplasmic proteins play a central role.
These results represent a previously uncharacterized molecular mechanism for metal/silver resistance.
Originele taal-2 | English |
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Pagina's | 39 |
Aantal pagina's | 1 |
Status | Published - 20 okt 2017 |
Evenement | Belgian Society for Microbiology (BSM) Symposium 2017 - Academy Palace, Brussels, Belgium Duur: 20 okt 2017 → 20 okt 2017 https://belsocmicrobio.be/bsm-meeting-2017-closed/ |
Seminar
Seminar | Belgian Society for Microbiology (BSM) Symposium 2017 |
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Land/Regio | Belgium |
Stad | Brussels |
Periode | 20/10/17 → 20/10/17 |
Internet adres |