Seasonal changes in peryphytic microbial metabolism determining mercury methylation in a tropical wetland.

Autor: Lázaro WL; Centro de Estudos em Limnologia Biodiversidade e Etnobiologia do Pantanal, Universidade do Estado de Mato Grosso (UNEMAT), Brazil. Electronic address: wilkinsonlopes@gmail.com., Díez S; Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Barcelona, Spain. Electronic address: sergi.diez@idaea.csic.es., da Silva CJ; Centro de Estudos em Limnologia Biodiversidade e Etnobiologia do Pantanal, Universidade do Estado de Mato Grosso (UNEMAT), Brazil; Rede Bionorte, Doutorado em Biodiversidade e Biotecnologia da Amazônia Legal, Brazil., Ignácio ÁRA; Centro de Estudos em Limnologia Biodiversidade e Etnobiologia do Pantanal, Universidade do Estado de Mato Grosso (UNEMAT), Brazil., Guimarães JRD; Laboratório de Traçadores. Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro (UFRJ), Brazil.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2018 Jun 15; Vol. 627, pp. 1345-1352. Date of Electronic Publication: 2018 Feb 07.
DOI: 10.1016/j.scitotenv.2018.01.186
Abstrakt: Mercury (Hg) methylation, a key process in the biogeochemical cycle of Hg, is mainly attributed to sulfate-reducing bacteria and methanogenic Archaea. However, environmental regulation by these groups has not yet been ascertained in tropical environments, especially in respect to the seasonal flood flooding. This work evaluated the variation of net methylmercury production potential in relation to biological characteristics of the periphyton, environmental factors, and flood pulse seasons. Our results indicate that there is a seasonal change between metabolic groups as main Hg methylators, sulfate-reducing bacteria in the dry season and methanogenic Archaea in the flood season. In addition, there was a positive relationship between dissolved organic carbon (DOC), phosphorus, cyanobacteria biovolume, and periphytic Hg methylation potential. These results shed a new light on MeHg production plasticity, mediated by landscape and flood pulses in tropical wetlands, as well as on ecological relationships within the periphyton.
(Copyright © 2018 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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