Use of synchrotron radiation x-ray fluorescence and x-ray absorption spectroscopy to investigate bioaccumulation, molecular target and biotransformation of volcanic elements

LAMELA, P.A.; PEREZ, R.D.; PÉREZ, C.A.; BONGIOVANNI, G.

X-RAY SPECTROMETRY

JOHN WILEY & SONS LTD

Lugar: Londres; Año: 2018 p. 1 - 21

0049-8246

Due to the fact that toxic elements have a strong impact on ecosystems, including human health, methods of their determination and mitigation have received special attention in recent years. Here, we highlight the wide range of benefits of X-ray fluorescent spectroscopy (XRF) in the field of environmental research. Hostile volcanic environments were identified and representative organisms were analyzed by differents μ-SRXRF (micro Synchrotron Radiation X-Ray Fluorescence) set-up. The S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn,Ga, Ge, As, Se, Br, Rb, and Sr concentrations were measured, showing that the volcanic elements Ti, Mn and Fe, were abundant in this exposed biota, while a high concentration of As was only found in cyanobacteria (24.5 μ/g). In order to characterize this organism, arsenic metabolites were analyzed by μ-SRXRF-XANES (combining μ-SRXRF and X-ray Absorption Near Edge Structure), showing an active methylation capacity. Their proteins were separated by SDS-PAGE, electrotransferred to nitrocellulose and then scanning with μ-SRXRF. Defined protein bands containing K, Ca, Ti, Mn, Fe and Zn were found. Finally, a high capacity of Ti>Fe>Cr>Mn>Ca>As retention (low leaching), was revealed by μ-SRXRF,after aqueous/alcoholic extraction assisted by ultra-sonication. We speculate that these cyanobacteria could be interesting candidates for water treatment. Based in these results, we conclude that μ-SRXRF can be a valuable tool to study the biological fate of toxic elements in the environment, making broad data available about their molecular targets and the metabolic pathway in pollutant tolerance. The μ-SRXRF may also assist in remediation researches.