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Capacity and phenotypic characterization of isolated methylmercury marine bacteria detoxifiers

Authors :
Sanz-Sáez, Isabel
Pereira Garcia, Carla
Trujillo Cuadra, Laura
Pla Ferriol, Martí
Capilla Lloris, Miguel
Bravo, Andrea G.
Rodríguez Martín-Doimeadios, Rosa C.
Sebastián, Marta
Acinas, Silvia G.
Sánchez, Olga
Source :
Digital.CSIC. Repositorio Institucional del CSIC, instname
Publication Year :
2019
Publisher :
Sociedad Ibérica de Ecología, 2019.

Abstract

1st Iberian Ecological Society Meeting (2019); XIV Congreso Nacional de la Asociación Española de Ecología Terrestre (AEET), Ecology: an integrative science in the Anthropocene, 4-7 February 2019, Barcelona, Spain<br />Bacterial transformation of inorganic-mercury (HgII) and methylmercury (MeHg) is performed by the mer operon and is known to beharboured in diverse marine bacterial taxa. However, little is known about the tolerance capacity and phenotypic characterizationof marine bacteria displaying merA (volatilizes HgII to Hg0) or merAB (volatilizes HgII to Hg0 and degrade MeHg to HgII) genes. Inthis study, we performed a functional screening of these genes in 306 marine bacterial cultures from Alteromonas sp. and Mari-nobacter sp. since they have the mer operon and present a broad geographical distribution covering different depths and latitudinalgradients. Our PCR functional screening identified 24.5% of the isolates presenting the merA and only 9.2% presenting both merABgenes. Additionally, the Minimum Inhibitory Concentration (MIC) for HgCl2 and MeHg was determined for a total of 103 PCR positivestrains. Strain ISS312 presented the highest tolerance, with a MIC of 70uM and 10uM for HgCl2 and MeHg, respectively. This strain,affiliated to Alteromonas mediterranea DE, presented a 10h longer lag-phase and a slower growth rate when growing with MeHg,but reached a similar concentration (cells/ml) compared to the control. Additionally, it was able to degrade 5uM of MeHg in 24h. In-terestingly, inclusion bodies (IB) were observed inside cells and TEM-EDX analysis pointed out to poly-P as their probable nature. Insummary, our functional screening analyses helped to understand the capacity of marine bacteria to detoxify MeHg and to proposeAlteromonas sp. ISS312 as a potential candidate to be used in bioremediation experiments

Details

Database :
OpenAIRE
Journal :
Digital.CSIC. Repositorio Institucional del CSIC, instname
Accession number :
edsair.dedup.wf.001..465428a7f2f11ba64f67bdb6ce67e3b6