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- Co-metabolic degradation of mono-fluorophenols by the ectomycorrhizal fungi Pisolithus tinctoriusPublication . Franco, Albina R.; Ferreira, António C.; Castro, Paula M. L.The release of fluorinated organic compounds from fire retardants or agrochemical products may have a significant negative effect on soil ecosystems. In this study, the ability of Pisolithus tinctorius to tolerate and degrade mono-fluorophenols (FP) was assessed. In vitro studies showed fungal growth in the presence of 0.45 mM of 2-FP and 3-FP, but not in the presence of 4-FP. P. tinctorius was able to degrade up to 79% and 92% of 1 mM 2-FP and 3-FP, respectively, in glucose supplemented liquid medium, suggesting that 2- and 3-FP degradation occurred in co-metabolism with glucose consumption. 3-Fluorocatechol (FC) and 4-FC were identified as metabolic intermediates using HPLC and LC–MS. Liberation of fluoride was not detected suggesting that a fluorinated dead-end product was formed. In extracts of cells collected at the end of cultures supplemented with the mono-FPs, a metabolic intermediate compatible with a mass corresponding to a fluoromuconate compound, according to LC–MS data, was recovered. The results further suggest that ectomycorrhizal fungi may be able to degrade mono-FP in pure culture while using glucose as a carbon source, through a similar pathway as that found in bacteria. To our knowledge, this is the first time that degradation of mono-FPs by an ectomycorrhizal fungus is reported.
- Detection of the crystallization process of paracetamol with a multi-mode optical fiber in a reflective configurationPublication . Soares, Liliana; Novais, Susana; Ferreira, António; Frazão, Orlando; Silva, SusanaA configuration of a refractometer sensor is described with the aim of optically detecting the crystallization process of paracetamol. The developed sensing head is based on a conventional cleaved multi-mode fiber. The fiber tip sensor structure was submitted to contact with the liquid of interest (paracetamol fully dissolved in 40% v/v of ethanol/water) and the crystallization process of paracetamol, induced with continued exposure to air, was monitored in real time.
- Continuous-flow precipitation as a route to prepare highly controlled nanohydroxyapatite: In vitro mineralization and biological evaluationPublication . Castro, Filipa; Ribeiro, Viviana. P.; Ferreira, António; Oliveira, Ana L.; Reis, Rui L.; Teixeira, José A.; Rocha, FernandoThis work reports the biological evaluation of nanosized hydroxyapatite (HAp) previously synthesized by continuous-flow precipitation in a scaled-up meso oscillatory flow reactor (meso-OFR). Physicochemical characterization of the synthesized HApsuggests high surface reactivity namely because of its high specific surface area and low crystallinity. On the other hand, in vitro biomineralization assays demonstrated the apatite-forming activity of the prepared HAp and their higher surface reactivity when compared to a commercial HAp. Furthermore, human osteoblastic-like (Saos-2) cells culture evidenced that the synthesized HAp stimulated cell proliferation, especially when applied at lower concentrations (30 and 50 μg ml−1), although its cellular uptake behavior. Therefore, the prepared HApshows immense potential as biomedical material, as well as drug and gene delivery vehicle. The results are also very promising regarding further scaling up of the process, as the designed methodology allow for the preparation in a continuous mode of nanosized HAp with controlled physico-chemical properties.
- Application of a high-throughput process analytical technology metabolomics pipeline to Port wine forced ageing processPublication . Castro, Cristiana C.; Martins, R.C.; Teixeira, José A.; Ferreira, António C. SilvaMetabolomics aims at gathering the maximum amount of metabolic information for a total interpretation of biological systems. A process analytical technology pipeline, combining gas chromatography-mass spectrometry data preprocessing with multivariate analysis, was applied to a Port wine "forced ageing" process under different oxygen saturation regimes at 60 °C. It was found that extreme "forced ageing" conditions promote the occurrence of undesirable chemical reactions by production of dioxane and dioxolane isomers, furfural and 5-hydroxymethylfurfural, which affect the quality of the final product through the degradation of the wine aromatic profile, colour and taste. Also, were found high kinetical correlations between these key metabolites with benzaldehyde, sot-olon, and many other metabolites that contribute for the final aromatic profile of the Port wine. The use of the kinetical correlations in time-dependent processes as wine ageing can further contribute to biological or chemical systems monitoring, new biomarkers discovery and metabolic network investigations.