Aridane G. Gonzalez, investigador externo de nuestro proyecto EACFe, ha participado en el congreso internacional: Ocean Sciences Meeting de New Orleans (21 - 26 de Febrero de 2016). Allí ha presentado un póster invitado a la sesión: Trace Metal Bioavailability and Metal-Microorganism Interactions.
El OSM-2016 ha sido muy productivo. Han habido sesiones muy interesantes de la biogeoquímica de metales traza en el océano, especiación química de metales y la interacción de metales con microorganismos. Ademas de muchas sesiones paralelas de gran interés por su papel en la química de metales, como pueden ser las sesiones de nutrientes y de la propiedades de la materia orgánica disuelta.
RESUMEN - ABSTRACT
Persistence of Fe(II) in seawater
due to the effect of organic exudates from D.
tertiolecta
The chemistry
of iron is highly affected by the presence of organic ligands in solution,
where the exudates produced by microorganisms are playing a key role. In this
sense, the Fe(II) oxidation was studied in the presence of exudates produced by Dunaliella tertiolecta. In this sense, the Fe(II) oxidation rate
was studied at different stages of growth, where the Dissolved Organic Carbon
(DOC) increased from 2.1 to 7.1 mg L-1. The oxidation of Fe(II) was
also studied as a function of pH (7.2 - 8.2), temperature (5-35 °C) and
salinity (10-37). The presence of exudates invoked in a decreasing of Fe(II)
rate constant with respect to the control seawater.
On the other hand, the phenolic profile of the
exudates and extracts of D. tertiolecta
were studied in the stationary phase (8 days of culture) and compared with the
control seawater. The phenolic profile revealed an enrichment in phenolic
compounds that are able to reduce Fe(III) to Fe(II) acting as a source of
Fe(II) in the surface waters. Then, two phenolic compounds as catechin and
sinapic acid were selected to studied the reduction of Fe(III) in seawater from
pH 8.0 to 6.0. The reduction of Fe(III) by these two phenolic compounds was a
pH-dependent process.
The role of
organic exudates by D. tertiolecta is
favouring the persistence of Fe(II) in surface waters and under ocean
acidification conditions must be factored due to the key role played by them on
the Fe(II) oxidation rate at lower pH values. As they are responsible for
decreasing the Fe(II) oxidation rate, these experiments indicated that the
exudates of D. tertiolecta can act as
an important Fe(II) supplier to other marine organisms.
FOTOS DEL CONGRESO
