Browsing by Author "Alonso, Esteban"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
- Novel bacterial strains for nonylphenol removal in water and sewage sludge: insights from gene expression and toxicityPublication . Lara-Moreno, Alba; Aguilar-Romero, Inés; Madrid, Fernando; Villaverde, Jaime; Carlier, Jorge; Santos, Juan Luís; Alonso, Esteban; Morillo, EsmeraldaAbstract: 4-Nonylphenols (4-NPs) are persistent endocrine disruptors frequently found in wastewater treatment plant (WWTP) effluents and sewage sludge. This study evaluated the ability of eight bacterial strains that were isolated from sewage sludge to degrade 4-n-NP in an aqueous solution. Bacillus safensis CN12, Shewanella putrefaciens CN17, and Alcaligenes faecalis CN8 showed the highest degradation rates, removing 100%, 75%, and 74% of 4-n-NP (10 mg L−1 ), with DT50 values of 0.90, 8.9, and 10.4 days, respectively. Despite the reduction in 4-n-NP concentrations, ecotoxicity assays revealed that the resulting transformation products (TPs) were more toxic than the parent compound. To investigate the potential degradation mechanisms, in silico and gene expression analyses were conducted on B. safensis CN12, revealing a significant upregulation of the multicopper oxidase gene, cotA (7.25-fold), and the ring-cleaving dioxygenase gene, mhqO (13.9-fold). Although the CN12 strain showed potential for mineralization based on gene expression studies, this was not observed in the aqueous solution. However, when 4-n-NP was adsorbed on sludge and treated with CN12 in the presence of hydroxypropyl-β-cyclodextrin (HPBCD) as a bioavailability enhancer, mineralization reached up to 33%, indicating a synergistic effect with the native sludge microbiota.
- Ultrasound-assisted extraction as an easy-to-perform analytical methodology for monitoring ibuprofen and its main metabolites in musselsPublication . Malvar, José Luis; Santos, Juan Luis; Martín, Julia; Aparicio, Irene; Fonseca, Tainá; Bebianno, Maria; Alonso, EstebanNon-steroidal anti-infammatory drugs (NSAIDs) have been reported to be the main pharmaceutical class accumulated in seafood. Among them, ibuprofen (IBU) is of special concern as it is used worldwide to treat common pain, does not require a medical prescription, it is often taken in a high daily dose, and has been reported to cause potential adverse efects on aquatic organisms. IBU is highly transformed into hydroxy- and carboxy-metabolites and/or degradation products generated not only after its administration but also during wastewater treatment or in the environment. These compounds can be present in the environment at higher concentrations than IBU and present higher toxicity. In this work, a low-cost and afordable routine analytical method was developed and validated for the frst-time determination of IBU and its main metabolites in mussels. The method is based on ultrasound-assisted extraction (UAE), clean-up by dispersive solid-phase extraction (d-SPE) and analytical determination by liquid chromatography-tandem mass spectrometry. Box-Behnken experimental design was used for method optimisation to better evaluate the infuence and interactions of UAE and d-SPE variables. Extraction recoveries were in the range from 81 to 115%. Precision, expressed as relative standard deviation, was lower than 7%. Method detection limits were in the range from 0.1 to 1.9 ng g−1 dry weight. The method was successfully applied to wild mussels.