Percorrer por autor "Carvalho, Maria de Fátima"
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- Bioreciclagem têxtil e saúde ambiental: uma abordagem inovadora para a redução de riscos e promoção da sustentabilidadePublication . Almeida, Liliana; Alexandrino, Diogo A. M.; Ribeiro, Nuno; Oliveira, Rui S.; Carvalho, Maria de Fátima; Freitas, Marisa; Alexandrino, DiogoA poluição associada à indústria têxtil representa um desafio crescente para a saúde pública e ambiental. O descarte inadequado de resíduos têxteis, frequentemente em aterros, ou o seu tratamento por incineração (Azcona et al., 2023), contribui para a emissão de compostos tóxicos, microplásticos e partículas inaláveis, com efeitos adversos sobre a qualidade do ar, da água e do solo (Shirvanimoghaddam et al., 2020; Juanga-Labayen et al., 2022). Assim, é urgente promover estratégias de gestão sustentável deste tipo de resíduos que minimizem riscos para a saúde humana e para os ecossistemas. O presente trabalho visa desenvolver e avaliar processos de bioreciclagem de resíduos têxteis com base em microrganismos celulolíticos, como alternativa ecológica às práticas convencionais. O estudo tem sido conduzido com base numa abordagem interdisciplinar que integra metodologias da microbiologia ambiental, biotecnologia e saúde ambiental. Inicialmente, procedeu-se à caracterização físico-química dos resíduos têxteis pós-industriais e pós-consumo. Posteriormente, realizaram-se ensaios de biodegradação in vitro. Estes ensaios possibilitaram monitorizar parâmetros ambientais e observar alterações estruturais nas fibras têxteis, avaliando a sua suscetibilidade à degradação biológica. Paralelamente, foram isolados microrganismos a partir de diferentes matrizes ambientais, incluindo composto, solo e efluentes, recorrendo a meios seletivos para microrganismos celulolíticos. A caracterização dos resíduos têxteis permitiu definir as configurações experimentais a testar, centradas em fibras de algodão e liocel, tingidas e não tingidas. Os ensaios de biodegradação realizados evidenciaram alterações morfológicas e estruturais nas fibras, compatíveis com processos iniciais de despolimerização e fragmentação da celulose. Paralelamente, o isolamento de microrganismos resultou na obtenção de diversas colónias com atividade celulolítica. Entre os isolados identificados destacam-se fungos dos géneros Neurospora e Aspergillus, bem como bactérias dos géneros Glutamicibacter e Bacillus, reconhecidos pelo seu potencial na degradação de polímeros de origem celulósica. Os resultados preliminares deste estudo sugerem que a (bio)reciclagem pode constituir uma alternativa eficaz e ambientalmente segura às práticas convencionais de gestão de resíduos têxteis, contribuindo para a redução da poluição e da consequente exposição humana a compostos tóxicos. A integração de microrganismos celulolíticos em processos de gestão de resíduos poderá representar um avanço relevante na promoção da saúde ambiental e na prevenção de riscos sanitários associados à indústria têxtil.
- Exploring the biosurfactant potential of Actinobacteria isolated from Ruta graveolensPublication . Ferreira, Sílvia; Ribeiro, Inês; Oliveira, Rui S.; Carvalho, Maria de FátimaBiosurfactants are surface-active compounds known for their emulsifying properties and numerous advantages, including low environmental toxicity, eco-friendliness, biodegradability and acceptability. These molecules are amphiphilic, containing both hydrophilic and hydrophobic ends, allowing them to interact at the aqueous-non-aqueous interface. Bacterial biosurfactants are interesting due to their various fields of applications, including biomedicine, cosmetics, food, pharmaceutics, water treatment and oil recovery. Actinobacteria are an important group of microorganisms with high potential for producing different bioactive metabolites including antimicrobial, anticancer and other pharmaceutical compounds. Medicinal plants,such as Ruta graveolens, are a rich source of bioactive compounds, and the association of actinobacteria endophytes with such plants are an attractive source for bioprospecting for novel compounds with biomedical and industrial applications. The purpose of this study was to explore the biosurfactant activity of actinobacterial strains previously isolated from R. graveolens. Fifteen previously isolated actinobacterial strains were inoculated into 100 mL Erlenmeyer flasks containing 30 mL of Kim’s broth supplemented with 3% filtered olive oil as a hydrophobic carbon source. After two weeks, biosurfactant productionwas analyzed by measuring the emulsification activity. Eight out of the 15 actinobacterial strains showed emulsification activity. All results were compared with a positive control consisting of Triton X100 (1mg/ml), and a negative control consisting in Kim’s broth. Almost all strains that revealed positive activity are affiliated to the actinobacterial species Tsukamurella tyrosinosolvens (7/8), with one strain belonging to the species Microbacterium gisengiterae. Comparative analysis with the positive control (with an emulsification activity of 60%), indicated that 3/8 samples showed high emulsification activity (>40%), 1 showed moderate activity (37%) and 4/8 showed low/moderate activity (20-30%). The subsequent phases of this study will involve analyzing if the potential biosurfactant compounds can reduce the surface tension and if they can represent new molecules.
- In vitro antimicrobial activity of volatile compounds from the Lichen Pseudevernia furfuracea (L.) Zopf. against multidrug-resistant bacteria and fish pathogensPublication . Essadki, Yasser; Hilmi, Adel; Cascajosa-Lira, Antonio; Girão, Mariana; Darrag, El Mehdi; Rosário Martins, Maria; Romane, Abderrahmane; Zerrifi, Soukaina El Amrani; Mugani, Richard; Tazart, Zakaria; Redouane, El Mahdi; Jos, Angeles; Cameán, Ana M.; Vasconcelos, Vitor; Campos, Alexandre; Khalloufi, Fatima El; Oudra, Brahim; Barakate, Mustapha; Carvalho, Maria de FátimaLichens are symbiotic organisms with unique secondary metabolism. Various metabolites from lichens have shown antimicrobial activity. Nevertheless, very few studies have investigated the antimicrobial potential of the volatile compounds they produce. This study investigates the chemical composition and antimicrobial properties of volatile compounds from Pseudevernia furfuracea collected in two regions of Morocco. Hydrodistillation was used to obtain volatile compounds from samples collected in the High Atlas and Middle Atlas. Gas chromatography–mass spectrometry (GC-MS) analysis identified phenolic cyclic compounds as the primary constituents, with atraric acid and chloroatranol being the most abundant. Additionally, eight compounds were detected in lichens for the first time. The antimicrobial activity of these compounds was assessed using disc diffusion and broth microdilution methods. Both samples demonstrated significant antimicrobial effects against multidrug-resistant human bacteria, reference microorganisms, fish pathogens, and Candida albicans, with minimum inhibitory concentrations (MICs) ranging from 1000 µg/mL to 31.25 µg/mL. This study provides the first report on the volatile compounds from Pseudevernia furfuracea and their antimicrobial effects, particularly against fish pathogens, suggesting their potential as novel antimicrobial agents for human and veterinary use. Further research is warranted to explore these findings in more detail.
- MarinEye – A tool for marine monitoringPublication . Martins, Alfredo; Dias, André; Silva, Eduardo; Ferreira, Hugo; Dias, Ireneu; Almeida, José Miguel; Torgo, Luís; Gonçalves, Marco; Guedes, Maurício; Dias, Nuno; Jorge, Pedro; Mucha, Ana Paula; Magalhães, Catarina; Carvalho, Maria de Fátima; Ribeiro, Hugo; Almeida, C. Marisa R.; Azevedo, Isabel; Ramos, Sandra; Borges, Teresa; Leandro, Sérgio Miguel; Maranhão, Paulo; Mouga, Teresa; Gamboa, Roberto; Lemos, Marco; Santos, Antonina dos; Silva, Alexandra; Teixeira, Bárbara Frazão e; Bartilotti, Cátia; Marques, Raquel; Cotrim, SóniaThis work presents an autonomous system for marine integrated physical-chemical and biological monitoring – the MarinEye system. It comprises a set of sensors providing diverse and relevant information for oceanic environment characterization and marine biology studies. It is constituted by a physical-chemical water properties sensor suite, a water filtration and sampling system for DNA collection, a plankton imaging system and biomass assessment acoustic system. The MarinEye system has onboard computational and logging capabilities allowing it either for autonomous operation or for integration in other marine observing systems (such as Observatories or robotic vehicles. It was designed in order to collect integrated multi-trophic monitoring data. The validation in operational environment on 3 marine observatories: RAIA, BerlengasWatch and Cascais on the coast of Portugal is also discussed.
- Unveiling Lichen’s Hidden Arsenal against multidrug resistance: A Systematic Review of their essential oils, volatile compounds and extracts with antimicrobial applicationsPublication . Essadki, Yasser; El Amrani Zerrifi, Soukaina; Carvalho, Maria de Fátima; Barros, Lillian; Vasconcelos, Vitor; Campos, Alexandre; El Khalloufi, Fatima; Oudra, Brahim; Martins, Rosário; Martins, RosarioThe increase in multidrug resistance in microorganisms and the rise of emergent infectious diseases worldwide is a threat to human and animal health. Therefore, research on new molecules with antibiotic potential is a priority. Lichens have a unique secondary metabolism with relatively untapped potential, yet their essential oils (EOs) and volatile organic compounds (VOCs) remain a relatively untapped resource. This systematic review was conducted following PRISMA 2020 guidelines, with a comprehensive search performed in the Web of Science database for studies published up to 2023. From 254 identified records, six studies involving nine lichen species (Evernia prunastri, Evernia divaricata, Cladonia rangiformis, Cladonia furcata, Parmotrema perlatum, Lichina pygmaea, Parmelia perlata, Hypogymnia physodes, and Parmelia sulcata) met the eligibility criteria. The synthesized data show that these volatile fractions possess significant antimicrobial potential, with minimum inhibitory concentrations (MICs) generally lower than 1 mg/mL. Major bioactive constituents identified include atraric acid, orsellinates, and various sesquiterpenes. While the current evidence highlights a strong potential of lichen volatiles against pathogens, research is limited to a small fraction of known species. This review identifies a critical gap in testing these compounds directly against MDR clinical isolates and suggests that future research should focus on high-biomass species and the heterologous expression of lichen biosynthetic genes to develop sustainable antimicrobial applications.