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Projeto de investigação
Linking Landscape, Environment, Agriculture and Food
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Chemical and Ecotoxicological Assessment of Agricultural Drainage Water from a Maize Crop Area
Publication . Palma, Patrícia; Catarino, Adriana; Silva, Emília; Alvarenga, Paula; GeoBioTec - Geobiociências, Geoengenharias e Geotecnologias; MDPI - Multidisciplinary Digital Publishing Institute
The use of agricultural drainage water (ADW) in irrigation is a great challenge, improving water use efficiency, nutrient circularity, and avoiding surface and ground-water contamination. The objective of this study was to evaluate the chemical and ecotoxicological characteristics of an ADW to analyze the safety of its reuse. An irrigated area with maize crops was selected (Tejo Basin, Portugal), where a subsurface structure for the recovery of ADW was installed, collecting the drainage in a pond and recycling it for crop irrigation. Water was collected monthly during the irrigation campaign of 2021 (April to August). Three herbicides and two metabolites were quantified, reaching a maximum concentration of 0.74 µg L−1 for S-metolachlor and 0.48 µg L−1 for terbuthylazine. The lethal bioassays did not detect toxicity, except for the sample collected in August toward Vibrio fisheri (EC50 = 25.2%). The samples were not toxic to Pseudokirchneriella subcapitata, with a growth inhibition rate of less than 10%. The low lethal and sublethal effects may be ascribed to the high nutrient concentration (e.g., 1.76 mg P L−1 and 98.9 mg NO3− L−1, in July) that could have masked toxic effects. Ecotoxicological responses support the option of ADW reuse in irrigation, offering a safe and sustainable solution for water and nutrient management.
Chitin-Glucan Complex Hydrogels
Publication . Araújo, Diana; Rodrigues, Thomas; Roma-Rodrigues, Catarina; Alves, Vítor D.; Fernandes, Alexandra R.; Freitas, Filomena; UCIBIO - Applied Molecular Biosciences Unit; DQ - Departamento de Química; DCV - Departamento de Ciências da Vida; MDPI - Multidisciplinary Digital Publishing Institute
Chitin-glucan complex (CGC) hydrogels were fabricated by coagulation of the biopolymer from an aqueous alkaline solution, and their morphology, swelling behavior, mechanical, rheological, and biological properties were studied. In addition, their in vitro drug loading/release ability and permeation through mimic-skin artificial membranes (Strat-M) were assessed. The CGC hydrogels prepared from 4 and 6 wt% CGC suspensions (Na51*4 and Na51*6 hydrogels, respectively) had polymer contents of 2.40 ± 0.15 and 3.09 ± 0.22 wt%, respectively, and displayed a highly porous microstructure, characterized by compressive moduli of 39.36 and 47.30 kPa and storage moduli of 523.20 and 7012.25 Pa, respectively. Both hydrogels had a spontaneous and almost immediate swelling in aqueous media, and a high-water retention capacity (>80%), after 30 min incubation at 37 °C. Nevertheless, the Na51*4 hydrogels had higher fatigue resistance and slightly higher-water retention capacity. These hydrogels were loaded with caffeine, ibuprofen, diclofenac, or salicylic acid, reaching entrapment efficiency values ranging between 13.11 ± 0.49% for caffeine, and 15.15 ± 1.54% for salicylic acid. Similar release profiles in PBS were observed for all tested APIs, comprising an initial fast release followed by a steady slower release. In vitro permeation experiments through Strat-M membranes using Franz diffusion cells showed considerably higher permeation fluxes for caffeine (33.09 µg/cm2/h) and salicylic acid (19.53 µg/cm2/h), compared to ibuprofen sodium and diclofenac sodium (4.26 and 0.44 µg/cm2/h, respectively). Analysis in normal human dermal fibroblasts revealed that CGC hydrogels have no major effects on the viability, migration ability, and morphology of the cells. Given their demonstrated features, CGC hydrogels are very promising structures, displaying tunable physical properties, which support their future development into novel transdermal drug delivery platforms.
Novel Hydrogel Membranes Based on the Bacterial Polysaccharide FucoPol
Publication . Araújo, Diana; Martins, Matilde; Concórdio-Reis, Patrícia; Roma-Rodrigues, Catarina; Morais, Maria; Alves, Vítor D.; Fernandes, Alexandra R.; Freitas, Filomena; UCIBIO - Applied Molecular Biosciences Unit; DQ - Departamento de Química; DCV - Departamento de Ciências da Vida; DCM - Departamento de Ciência dos Materiais; CENIMAT-i3N - Centro de Investigação de Materiais (Lab. Associado I3N); Molecular Diversity Preservation International (MDPI)
FucoPol, a fucose-rich polyanionic polysaccharide, was used for the first time for the preparation of hydrogel membranes (HMs) using Fe3+ as a crosslinking agent. This study evaluated the impact of Fe3+ and FucoPol concentrations on the HMs’ strength. The results show that, above 1.5 g/L, Fe3+ concentration had a limited influence on the HMs’ strength, and varying the FucoPol concentration had a more significant effect. Three different FucoPol concentrations (1.0, 1.75 and 2.5 wt.%) were combined with Fe3+ (1.5 g/L), resulting in HMs with a water content above 97 wt.% and an Fe3+ content up to 0.16 wt.%. HMs with lower FucoPol content exhibited a denser porous microstructure as the polymer concentration increased. Moreover, the low polymer content HM presented the highest swelling ratio (22.3 ± 1.8 g/g) and a lower hardness value (32.4 ± 5.8 kPa). However, improved mechanical properties (221.9 ± 10.2 kPa) along with a decrease in the swelling ratio (11.9 ± 1.6 g/g) were obtained for HMs with a higher polymer content. Furthermore, all HMs were non-cytotoxic and revealed anti-inflammatory activity. The incorporation of FucoPol as a structuring agent and bioactive ingredient in the development of HMs opens up new possibilities for its use in tissue engineering, drug delivery and wound care management.
Poly(Ethylene glycol) diacrylate iongel membranes reinforced with nanoclays for co2 separation
Publication . Nabais, Ana R.; Francisco, Rute O.; Alves, Vítor D.; Neves, Luísa A.; Tomé, Liliana C.; LAQV@REQUIMTE; DQ - Departamento de Química; MDPI AG
Despite the fact that iongels are very attractive materials for gas separation membranes, they often show mechanical stability issues mainly due to the high ionic liquid (IL) content (≥60 wt%) needed to achieve high gas separation performances. This work investigates a strategy to improve the mechanical properties of iongel membranes, which consists in the incorporation of montmorillonite (MMT) nanoclay, from 0.2 to 7.5 wt%, into a cross-linked poly(ethylene glycol) diacrylate (PEGDA) network containing 60 wt% of the IL 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2mim][TFSI]). The iongels were prepared by a simple one-pot method using ultraviolet (UV) initiated polymerization of poly(ethylene glycol) diacrylate (PEGDA) and characterized by several techniques to assess their physico-chemical properties. The thermal stability of the iongels was influenced by the addition of higher MMT contents (>5 wt%). It was possible to improve both puncture strength and elongation at break with MMT contents up to 1 wt%. Furthermore, the highest ideal gas selectivities were achieved for iongels containing 0.5 wt% MMT, while the highest CO2 permeability was observed at 7.5 wt% MMT content, due to an increase in diffusivity. Remarkably, this strategy allowed for the preparation and gas permeation of self-standing iongel containing 80 wt% IL, which had not been possible up until now.
Non-targeted metabolomic analysis of field-grown Coffea arabica cultivars reveals distinct leaf metabolic signatures
Publication . Carréra, Jéfyne Campos; Guerra-Guimarães, Leonor; D’Auria, John Charles; Sartori, Luana de Jesus; Pinheiro, Carla; Silva, Vânia Aparecida; Volpato, Margarete Lordelo; Carvalho, Gladyston Rodrigues; Mori, Fabio Akira; UCIBIO - Applied Molecular Biosciences Unit; DCV - Departamento de Ciências da Vida; Springer Science + Business Media
This study conducted a non-targeted metabolomic analysis of five Coffea arabica L. cultivars grown in the field experimental areas of the Cerrado Mineiro (Minas Gerais State, Brazil) to identify their metabolic fingerprints. The five cultivars selected for this study were chosen based on their specific genetic backgrounds and traits, including disease resistance, productivity, and cup quality. A total of 463 metabolic features were detected in the overall C. arabica metabolome, with the major metabolic classes comprising sugars, amino acids, lipids, phenylpropanoids, and phenolic compounds. Among these, 41 metabolites were identified as key discriminators among the five cultivars. Partial least squares discriminant analysis (PLS-DA) revealed distinct metabolic profiles, highlighting ferulic acid, theobromine, octopamine, rosmarinic acid, and gibberellin as key metabolites. These findings emphasize the importance of phenolic compounds and alkaloids in cultivar discrimination. The most relevant metabolic markers associated with environmental stress tolerance suggest their potential as biochemical indicators for selecting resilient cultivars, thereby contributing to coffee breeding programs. Notably, this study is the first documented characterization of the leaf metabolome of field-grown C. arabica cultivars, with Catiguá MG2 emerging as the most distinct. Our findings demonstrate the efficacy of metabolomic fingerprinting via non-targeted metabolomic as a powerful tool for differentiating coffee cultivars and for precision breeding strategies.
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Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
6817 - DCRRNI ID
Número da atribuição
UIDP/04129/2020