| Title | A phytochelatin-based bioassay in marine diatoms useful for the assessment of bioavailability of heavy metals released by polluted sediments. |
| Abstract | The aim of the present work was to develop a new bioassay involving the presence of phytochelatins (PCs), detoxifying intracellular metal-binding peptides, in microalgae as response to metal bioavailability in re-suspensions of metal-polluted marine sediments. For this purpose, the synthesis of PCs has been studied in laboratory cultures of three marine diatoms, namely Phaeodactylum tricornutum, Thalassiosira weissflogii and Skeletonema costatum, exposed to elutriates of sediments collected in a polluted coastal area in the province of Pisa (Tuscany, Italy). Short- and long-term incubations in the elutriates of two marine sediments (named A and B) exhibited an increase of PCs synthesis in all the phytoplanktonic species examined, when the elutriate concentration increased from 0% to 100%. Elutriate B, which was mainly contaminated by Cd, was shown to be more effective to induce PCs than elutriate A, which was richer in Cu and TOC. The results show that the PCs response, in the microalgae examined, was species-specific. Our data also show that the PCs synthesis occurred before the growth rate was affected, thereby indicating that PCs can be considered as an early warning response of metal exposure. The PCs response in exponentially growing cultures of T. weissflogii, which was found to be the most sensitive alga, increased when the initial cellular density decreased. Finally, the positive relationship obtained between the cellular PCs concentration in T. weissflogii and the degree of metal contamination of the elutriates from twelve sediments collected in a metal-polluted coastal area, confirmed that the PCs-induction test can be applied in field studies. In conclusion, the response of these marine microalgae suggests that these cellular peptides could represent an excellent biomarker of metal exposure, which is useful for the assessment of sediment toxicity, by carrying out PCs-induction tests on sediment elutriates. |
| Source | Environment international 35, pp. 532–538 |
| Keywords | BiomarkersPhytochelatinsMicroalgaeHeavy metalsMarine sediments |
| Journal | Environment international |
| Editor | Pergamon., New York, Stati Uniti d'America |
| Year | 2009 |
| Type | Articolo in rivista |
| DOI | 10.1016/j.envint.2008.09.012 |
| Authors | Morelli E.; Marangi M.L.; Fantozzi L. |
| Text | 9751 2009 10.1016/j.envint.2008.09.012 ISI Web of Science WOS 000265172900016 Biomarkers Phytochelatins Microalgae Heavy metals Marine sediments A phytochelatin based bioassay in marine diatoms useful for the assessment of bioavailability of heavy metals released by polluted sediments. Morelli E.; Marangi M.L.; Fantozzi L. Elisabetta Morelli, Maria Luisa Marangi and Laura Fantozzi Istituto di Biofisica, Consiglio Nazionale delle Ricerche CNR , Area della Ricerca di Pisa, Via Moruzzi 1, 56124 Pisa, Italy The aim of the present work was to develop a new bioassay involving the presence of phytochelatins PCs , detoxifying intracellular metal binding peptides, in microalgae as response to metal bioavailability in re suspensions of metal polluted marine sediments. For this purpose, the synthesis of PCs has been studied in laboratory cultures of three marine diatoms, namely Phaeodactylum tricornutum, Thalassiosira weissflogii and Skeletonema costatum, exposed to elutriates of sediments collected in a polluted coastal area in the province of Pisa Tuscany, Italy . Short and long term incubations in the elutriates of two marine sediments named A and B exhibited an increase of PCs synthesis in all the phytoplanktonic species examined, when the elutriate concentration increased from 0% to 100%. Elutriate B, which was mainly contaminated by Cd, was shown to be more effective to induce PCs than elutriate A, which was richer in Cu and TOC. The results show that the PCs response, in the microalgae examined, was species specific. Our data also show that the PCs synthesis occurred before the growth rate was affected, thereby indicating that PCs can be considered as an early warning response of metal exposure. The PCs response in exponentially growing cultures of T. weissflogii, which was found to be the most sensitive alga, increased when the initial cellular density decreased. Finally, the positive relationship obtained between the cellular PCs concentration in T. weissflogii and the degree of metal contamination of the elutriates from twelve sediments collected in a metal polluted coastal area, confirmed that the PCs induction test can be applied in field studies. In conclusion, the response of these marine microalgae suggests that these cellular peptides could represent an excellent biomarker of metal exposure, which is useful for the assessment of sediment toxicity, by carrying out PCs induction tests on sediment elutriates. 35 Articolo pubblicato EI1846.pdf Articolo in rivista Pergamon. 0160 4120 Environment international Environment international Environ. int. Environment international. laura.fantozzi FANTOZZI LAURA elisabetta.morelli MORELLI ELISABETTA TA.P05.015.002 Meccanismi di risposta cellulare a contaminanti ambientali |
