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Elisabetta Loffredo
Ruolo
Professore Associato
Organizzazione
Università degli Studi di Bari Aldo Moro
Dipartimento
DIPARTIMENTO DI SCIENZE DEL SUOLO,DELLA PIANTA E DEGLI ALIMENTI
Area Scientifica
AREA 07 - Scienze agrarie e veterinarie
Settore Scientifico Disciplinare
AGR/13 - Chimica Agraria
Settore ERC 1° livello
Non Disponibile
Settore ERC 2° livello
Non Disponibile
Settore ERC 3° livello
Non Disponibile
Bisphenol A (BPA) is an endocrine disruptor compound (EDC) of xenobiotic origin occurring in natural waters and wastewaters, especially in the most industrialized and urbanized areas. Recent investigations report the use of ligninolytic fungi for the removal of aromatic contaminants, including some EDCs, from different matrices. Humic acids (HA) are widely spread in all natural systems and their presence is ascertained to interfere with microbial growth and activity. The objective of this study was to assess the capacity of three ligninolytic fungi, Trametes versicolor, Stereum hirsutum and Pleurotus ostreatus, to remove BPA at the concentration of 4.6 mg L1 from water. Fungal growth on potato dextrose agar (PDA), in the absence and in the presence of a leonardite HA or a green compost HA, was evaluated during the biodecontamination process. The methodological approach adopted in this study excluded the presence of the mycelium in the contaminated water. Results obtained evidenced a relevant removal of BPA by any fungus when PDA only was used as growing medium. The addition of leonardite HA and compost HA stimulated the mycelial growth of any fungus, especially T. versicolor, and significantly enhanced the removal of the contaminant from water by, respectively, T. versicolor only and T. versicolor and S. hirsutum.
Natural terrestrial and aquatic systems can be polluted with xenobiotic compounds possessing hormone-like activity, commonly known as endocrine disruptors (EDs).among EDs, there are bisphenol a (BPA), a component of plastics, 17α-ethinylestradiol (EE2), present in oral contraceptives, and linuron (LIN), a common herbicide. This work investigated the capacity of seedlings of radish and ryegrass to remove coexisting BPA, EE2 and LIN from three different aqueous media, a water enriched with natural organic matter (NOM) at a concentration of 20 mg/l, a lake water and a river water. BPA, EE2 and LIN were spiked at concentrations of 1, 0.1 and 1 mg/l (ed1,0.1,1), respectively, as well as tenfold higher concentrations(ed10,1,10). Radish was much more efficient than ryegrass, and removed the compounds in the order EE2>BPA>LIN, averagely in the three media, at both EDS concentrations. in particular, with ed1,0.1,1 mix, the highest removal was obtained for EE2 in all media (100%) and the lowest removal for LIN in nom solution (34%). with ed10,1,10 mix, radish removal capacity was maximum for EE2 in lake water (88%) and minimum for LIN in river water (30%). At both ED concentrations, ryegrass removed the compounds in the order BPA>EE2>LIN, averagely in the three media. in particular, with ed1,0.1,1 mix, removal was maximum for EE2 in lake water (73%) and minimum for LIN in nom solution (6%). also with ed10,1,10mix, ryegrass seedlings removed significant amounts of EDS with a maximum for BPA in lake water (58%) and a minimum for LIN in river water (3%).
Phytoremediation of waters by aquatic organisms such as algae has been recently explored for the removal of organic pollutants possessing endocrine disrupting capacity. Monoraphidium braunii, a green alga known for rapid growth and good tolerance to different natural organic matter (NOM) qualities, was tested in this study for the ability to tolerate and remove the endocrine disruptor bisphenol A at concentrations of 2, 4 and 10 mg L−1, either in NOM-free or NOM-containing media. NOM at concentrations of 2, 5 and 20 mg L−1 of DOC, was added because it may interfere with xenobiotics and modify their effects, modulate algal growth performances or produce a trade-off of both effects. After 2 and 4 days of algal growth, the cell number and size, the maximum quantum yield of photosystem II in the dark or light adapted state, and the chlorophyll a content were recorded in order to evaluate the algal response to bisphenol A. Moreover, the residual bisphenol A was measured in the algal cultures by chromatographic technique. Results indicated that after 2 and 4 days bisphenol A at the lower concentrations was not toxic for alga, whereas at the highest concentration it reduced algal growth and photosynthetic efficiency. The sole NOM and its combinations with bisphenol A at the lower concentrations increased the cell number and the chlorophyll a content of algae. After 4-day growth, good removal efficiency was exerted by M. braunii at concentrations of 2, 4 and 10 mg L−1 removing, respectively, 39%, 48% and 35% of the initial bisphenol A. Lower removal percentages were found after 2-day growth in the different treatments. NOM at any concentration scarcely influenced the bisphenol A removal. On the basis of data obtained, the use of M. braunii could be reasonably recommended for the phytoremediation of aquatic environments from bisphenol A.
Allelochemical compounds released by plants to signal their presence and needs interact in soils with very important macromolecules, such as humic acids (HAs), which are able to modulate the ultimate effects on target organisms. Most of the available studies on plants and microorganisms report the effects of allelochemicals or those of humic fractions, separately. In this study, we investigated the combined activity of these two types of compounds on the soil-resident fungus Sclerotinia sclerotiorum. Thus, ferulic acid (FA), caffeic acid (CA), benzoic acid (BA), salicylic acid (SA), gallic acid (GA) and phthalic acid (PA), exogenously applied to the fungal growth medium, were tested both alone and in combination with a soil HA (SHA) and a compost HA (CHA). The two HAs were also tested alone on the fungus. When the allelochemicals were applied alone, only FA, BA and SA evidenced a significant inhibition of mycelial growth, whereas FA, BA and CA increased the number of sclerotia formed. The two HAs alone reduced the early growth of the fungus and markedly stimulated sclerotia formation. A significant attenuation or, in some cases, suppression of the allelochemical effect on mycelial growth was caused by the coexistence in the medium of the allelochemical and each HA, especially CHA. Moreover, in general, the combinations of HA-allelochemical significantly stimulated sclerotia formation, with respect to the sole allelochemical, but decreased it with respect to HA alone. Thus, investigations on the response of fungi to plant-released allelochemicals should not exclude interactive aspects of these compounds with ubiquitous coexisting humic macromolecules.
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