Role of different microbial compartments (biofilms, suspended matters, surface sediment) and some of them components (bacterial cells, extracellular polymeric substances and biominerals) on HgII methylation and reduction
Monomethylmercury formation, the neurotoxic form of mercury, is mainly linked to anaerobic microbial activity. In order to assess the relative contribution of several microbial compartments (biofilms, raw water and sediment) we evaluated methylation of samples from ponds of temperate area (Lorraine,...
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fttriple:oai:gotriple.eu:10670/1.mtibox 2023-05-15T18:28:21+02:00 Role of different microbial compartments (biofilms, suspended matters, surface sediment) and some of them components (bacterial cells, extracellular polymeric substances and biominerals) on HgII methylation and reduction Rôle de différents compartiments microbiens (biofilms, matières en suspension, sédiments de surface) et de leurs constituants (bactéries, polymères extracellulaires et biominéraux) sur la méthylation et la réduction de HgII Remy, Paul-Philippe Université de Lorraine Jorand, Frédéric 2015-07-01 http://www.theses.fr/2015LORR0076/document fr fre 10670/1.mtibox http://www.theses.fr/2015LORR0076/document other Theses.fr Méthylation du mercure Mare thermokarstique Biofilm Bactéries ferriréductrices Bactéries sulfatoréductrices Rouille verte Mercury methylation Thermokarst pond Iron reducing bacteria Sulfate reducing bacteria Green rust geo envir Thesis https://vocabularies.coar-repositories.org/resource_types/c_46ec/ 2015 fttriple 2023-01-22T16:57:07Z Monomethylmercury formation, the neurotoxic form of mercury, is mainly linked to anaerobic microbial activity. In order to assess the relative contribution of several microbial compartments (biofilms, raw water and sediment) we evaluated methylation of samples from ponds of temperate area (Lorraine, France) and from subarctic ponds (Nunavik, Quebec). Biofilms were not found to specifically promote mercury methylation, whereas sediment emerges as the main compartment involved in mercury methylation. The formation of methylmercury is positively linked to the temperature and to nutrients. Thus, by increasing the open water period, the water temperature and of the microbial activity, current climate changes may turn these ponds in preferential location for mercury methylation in the subarctic ecosystem. Finally, the reactivity of green rust, a mineral which can be produced by bacterial activity of environmental biofilms, may compete with mercury methylation by reducing HgII into Hg0 La formation de méthylmercure, la forme la plus toxique du mercure, est due à l’activité bactérienne anaérobie. Afin de connaître la contribution des compartiments microbiens (biofilms, eaux brutes, sédiments) dans la méthylation du mercure, nous avons évalué les vitesses de méthylation d’échantillons de mares de région tempérée (Lorraine) et subarctique (Québec, Canada). Si les bactéries des biofilms ne semblent pas plus méthylantes que d’autres, le sédiment apparait comme le compartiment le plus méthylant en lien avec la concentration en nutriments ainsi qu’avec la température. Ainsi, les changements climatiques actuels, en augmentant la température de l’eau et en favorisant l’activité biologique, peuvent faire de ces mares des sites préférentiels de la méthylation du mercure en milieu subarctique. Enfin, l’activité des biofilms a mené à la formation de rouille verte, un minéral capable de réduire HgII en mercure élémentaire, concurrençant ainsi la méthylation bactérienne Thesis Subarctic subarctique* Thermokarst Nunavik Unknown Canada Nunavik Verte ENVELOPE(141.192,141.192,-66.740,-66.740) |
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fttriple |
language |
French |
topic |
Méthylation du mercure Mare thermokarstique Biofilm Bactéries ferriréductrices Bactéries sulfatoréductrices Rouille verte Mercury methylation Thermokarst pond Iron reducing bacteria Sulfate reducing bacteria Green rust geo envir |
spellingShingle |
Méthylation du mercure Mare thermokarstique Biofilm Bactéries ferriréductrices Bactéries sulfatoréductrices Rouille verte Mercury methylation Thermokarst pond Iron reducing bacteria Sulfate reducing bacteria Green rust geo envir Remy, Paul-Philippe Role of different microbial compartments (biofilms, suspended matters, surface sediment) and some of them components (bacterial cells, extracellular polymeric substances and biominerals) on HgII methylation and reduction |
topic_facet |
Méthylation du mercure Mare thermokarstique Biofilm Bactéries ferriréductrices Bactéries sulfatoréductrices Rouille verte Mercury methylation Thermokarst pond Iron reducing bacteria Sulfate reducing bacteria Green rust geo envir |
description |
Monomethylmercury formation, the neurotoxic form of mercury, is mainly linked to anaerobic microbial activity. In order to assess the relative contribution of several microbial compartments (biofilms, raw water and sediment) we evaluated methylation of samples from ponds of temperate area (Lorraine, France) and from subarctic ponds (Nunavik, Quebec). Biofilms were not found to specifically promote mercury methylation, whereas sediment emerges as the main compartment involved in mercury methylation. The formation of methylmercury is positively linked to the temperature and to nutrients. Thus, by increasing the open water period, the water temperature and of the microbial activity, current climate changes may turn these ponds in preferential location for mercury methylation in the subarctic ecosystem. Finally, the reactivity of green rust, a mineral which can be produced by bacterial activity of environmental biofilms, may compete with mercury methylation by reducing HgII into Hg0 La formation de méthylmercure, la forme la plus toxique du mercure, est due à l’activité bactérienne anaérobie. Afin de connaître la contribution des compartiments microbiens (biofilms, eaux brutes, sédiments) dans la méthylation du mercure, nous avons évalué les vitesses de méthylation d’échantillons de mares de région tempérée (Lorraine) et subarctique (Québec, Canada). Si les bactéries des biofilms ne semblent pas plus méthylantes que d’autres, le sédiment apparait comme le compartiment le plus méthylant en lien avec la concentration en nutriments ainsi qu’avec la température. Ainsi, les changements climatiques actuels, en augmentant la température de l’eau et en favorisant l’activité biologique, peuvent faire de ces mares des sites préférentiels de la méthylation du mercure en milieu subarctique. Enfin, l’activité des biofilms a mené à la formation de rouille verte, un minéral capable de réduire HgII en mercure élémentaire, concurrençant ainsi la méthylation bactérienne |
author2 |
Université de Lorraine Jorand, Frédéric |
format |
Thesis |
author |
Remy, Paul-Philippe |
author_facet |
Remy, Paul-Philippe |
author_sort |
Remy, Paul-Philippe |
title |
Role of different microbial compartments (biofilms, suspended matters, surface sediment) and some of them components (bacterial cells, extracellular polymeric substances and biominerals) on HgII methylation and reduction |
title_short |
Role of different microbial compartments (biofilms, suspended matters, surface sediment) and some of them components (bacterial cells, extracellular polymeric substances and biominerals) on HgII methylation and reduction |
title_full |
Role of different microbial compartments (biofilms, suspended matters, surface sediment) and some of them components (bacterial cells, extracellular polymeric substances and biominerals) on HgII methylation and reduction |
title_fullStr |
Role of different microbial compartments (biofilms, suspended matters, surface sediment) and some of them components (bacterial cells, extracellular polymeric substances and biominerals) on HgII methylation and reduction |
title_full_unstemmed |
Role of different microbial compartments (biofilms, suspended matters, surface sediment) and some of them components (bacterial cells, extracellular polymeric substances and biominerals) on HgII methylation and reduction |
title_sort |
role of different microbial compartments (biofilms, suspended matters, surface sediment) and some of them components (bacterial cells, extracellular polymeric substances and biominerals) on hgii methylation and reduction |
publishDate |
2015 |
url |
http://www.theses.fr/2015LORR0076/document |
long_lat |
ENVELOPE(141.192,141.192,-66.740,-66.740) |
geographic |
Canada Nunavik Verte |
geographic_facet |
Canada Nunavik Verte |
genre |
Subarctic subarctique* Thermokarst Nunavik |
genre_facet |
Subarctic subarctique* Thermokarst Nunavik |
op_source |
Theses.fr |
op_relation |
10670/1.mtibox http://www.theses.fr/2015LORR0076/document |
op_rights |
other |
_version_ |
1766210795743477760 |