Scheda di dettaglio – i prodotti della ricerca
| Dato | Valore |
|---|---|
| Title | Dissolved gaseous mercury production in the dark: evidence for the fundamental role of bacteria in different types of Mediterranean water bodies. |
| Abstract | It is well established that the dissolved gaseous mercury (DGM) production in waters is mainly driven by photochemical processes. The present paper provides evidence for a significant bacteria-mediated DGM production, occurring also under dark conditions in environmentally different types of coastal water bodies of the Mediterranean basin. The DGM production was laboratory determined in sea, lagoon-brackish and lake water samples, comparing the efficiency of the DGM production processes in darkness and in the light. This latter condition was established by exposing samples at solar radiation intensity in the Photosyntetical Active Radiation region (PAR) of 200 W m(-2). Mercury reduction rate in the dark was of the order of 2-4% of the DGM production in lightness, depending on the total mercury concentration in the water, rather than the bacterial abundance in it. Support for the active bacterial role in mercury reduction rate under dark conditions was provided by: 1) absence of significant DGM production in sterilized water samples (following filtration treatment or autoclaving), 2) restored DGM production efficiency, following re-inoculation into the same water samples of representatives of their bacterial community, previously isolated and separately cultured. Notwithstanding the low bacteria-mediated vs. the high photo-induced DGM production, whatever natural water body was considered, it is worth stressing the significant contribution of this organismal-mediated process to oceanic mercury evasion, since it occurs continuously along the entire water column throughout the 24 h of the day. |
| Source | Science of the total environment 407, pp. 917–924 |
| Journal | Science of the total environment |
| Editor | Elsevier, Lausanne ;, Paesi Bassi |
| Year | 2009 |
| Type | Articolo in rivista |
| Authors | Fantozzi L., R. Ferrara, F.P. Frontini, F. Dini. |
| Text | 9747 2009 Dissolved gaseous mercury production in the dark evidence for the fundamental role of bacteria in different types of Mediterranean water bodies. Fantozzi L., R. Ferrara, F.P. Frontini, F. Dini. It is well established that the dissolved gaseous mercury DGM production in waters is mainly driven by photochemical processes. The present paper provides evidence for a significant bacteria mediated DGM production, occurring also under dark conditions in environmentally different types of coastal water bodies of the Mediterranean basin. The DGM production was laboratory determined in sea, lagoon brackish and lake water samples, comparing the efficiency of the DGM production processes in darkness and in the light. This latter condition was established by exposing samples at solar radiation intensity in the Photosyntetical Active Radiation region PAR of 200 W m 2 . Mercury reduction rate in the dark was of the order of 2 4% of the DGM production in lightness, depending on the total mercury concentration in the water, rather than the bacterial abundance in it. Support for the active bacterial role in mercury reduction rate under dark conditions was provided by 1 absence of significant DGM production in sterilized water samples following filtration treatment or autoclaving , 2 restored DGM production efficiency, following re inoculation into the same water samples of representatives of their bacterial community, previously isolated and separately cultured. Notwithstanding the low bacteria mediated vs. the high photo induced DGM production, whatever natural water body was considered, it is worth stressing the significant contribution of this organismal mediated process to oceanic mercury evasion, since it occurs continuously along the entire water column throughout the 24 h of the day. 407 Articolo in rivista Elsevier 0048 9697 Science of the total environment Science of the total environment Sci. total environ. FERRARA ROMANO laura.fantozzi FANTOZZI LAURA TA.P05.015.002 Meccanismi di risposta cellulare a contaminanti ambientali |