Biogeography and expression patterns of the genes involved in methylmercury degration and mercury reduction in the global deep ocean
| Autor: | Bravo, Andrea G., Sanz-Sáez, Isabel, Carreras, Joan-Martí, Sánchez, Olga, Gasol, Josep M., Duarte, Carlos M., Sánchez, Pablo, Acinas, Silvia G. |
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| Rok vydání: | 2019 |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | 14th International Conference on Mercury as a Global Pollutant (ICMGP 2019), 8-13 September 2019, Krakow, Poland.-- 1 page Microbes are important drivers of biogeochemical processes determining the fate of mercury (Hg) in the aquatic systems. In particular, they have a relevant role on formation and degradation of methylmercury (MeHg) but also on the reduction of inorganic divalent Hg (HgII) to elemental Hg0. The recent discovery of the gene cluster involved in MeHg formation (hgcA/hgcB) has improved the knowledge on identity and metabolic features of the microbial community performing this process. Yet, little is known about the diversity and expression of the organisms involved in MeHg demethylation and HgII reduction, which are carried out by the merB and merA genes, respectively. Here, we explore the temperate global deep ocean metagenomes and metatranscriptomes of the Malapasina 2010 circumnavigation from two different plankton size fractions (0.2-0.8 μm and 0.8-20 μm), commonly referred to the life-style of free-living and particle–attached microorganisms, respectively. By using multiple-specific hidden markov models (HMM), here we show the biogeography and expression patterns of merA and merB genes. Analysing the metagenomes, we observed that the abundance patterns of merA and merB responded to the life-style of the organisms, with higher abundance in the particle-attached size fraction, as well as to the oceanographic basin. Interestingly, the metatranscriptomes revealed that expression patterns of merA and merB genes differed with their corresponding abundances. For example, merA and merB expression patterns in the Canary Islands basin were significantly lower in particle-attached compared to the free-living fraction. Alteromonas and Pseudoalteromonas (Gammaproteobacteria) were important contributors to both the abundance and expression of merA and merB at a global scale. This study represents the first global deep ocean analysis of the merAB genes and transcripts and reveals the main players involved in the divalent-Hg reduction and MeHg degradation in the marine Hg biogeochemical cycle |
| Databáze: | OpenAIRE |
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