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- Chitosan-based films with beetroot pulp and banana pseudostem extracts for active food packagingPublication . Nascimento, Rosa E. A.; Sales, Joana; Alves, Vitor D.; Crespo, João G.; Neves, Luísa A.; DQ - Departamento de Química; LAQV@REQUIMTE; Instituto de Tecnologia Química e Biológica António Xavier (ITQB); ElsevierThe increasing demand for sustainable alternatives to petroleum-based food packaging materials has driven the development of biodegradable and functional films. This study explores the formulation and characterization of chitosan (Ch)-based films incorporating enzymatically recovered extracts from beetroot pulp (BP) and banana plant pseudostem (PS), for active food packaging applications. The incorporation of these plant-based by-products significantly influenced the films’ physicochemical and functional properties. Fourier transform infrared spectroscopy (FTIR) confirmed the successful integration of BP and PS extracts into the Ch matrix. Optical characterization revealed increased opacity, especially in Ch+BP films, which might offer potential for light-sensitive food protection. Morphological analysis showed homogeneous, dense structures, indicating good compatibility between Ch and the incorporated extracts. The films hydrophilicity, full water solubility within 24 h, and low water vapor barrier, envisage their applicability in single-use short shelf-life packages of low moisture content products, as ready-to-drink instant coffee sachets or protein powder single-serve sachets. The antioxidant performance of the films was markedly enhanced, with 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities of 9.92 ± 1.30 and 7.00 ± 0.37 µmol Trolox/g film for Ch+BP and Ch+PS films, respectively, reinforcing their potential as active packaging materials. This is the first report on Ch films incorporating enzymatic BP and PS extracts, presenting an innovative, circular economy driven strategy for agro-industrial waste valorisation through sustainable, active food packaging solutions.
- Linking NrfD/PsrC-like architecture to energy conservationPublication . Manteigas, Gonçalo; Catarino, Teresa; Vicente, João B.; Duarte, Américo G.; Pereira, Inês A.C.; Instituto de Tecnologia Química e Biológica António Xavier (ITQB); DQ - Departamento de Química; Wiley-BlackwellThe QrcABCD quinone reductase complex is an electrogenic complex present in sulfate-reducing bacteria of the Desulfobacterota phylum. It operates as a cytochrome c3:menaquinone oxidoreductase involved in electron transfer from periplasmic hydrogen or formate oxidation to the menaquinone (MK) pool. Two proteins in this complex, QrcC and QrcD, form a redox dimer (QrcCD) responsible for MK reduction coupled to proton uptake from the cytoplasm. QrcD belongs to the NrfD/PsrC family, and homologs are found in many bacterial redox complexes in different bioenergetic contexts. In this work a homologous overexpression system for QrcABCD was established in Nitratidesulfovibrio vulgaris Hildenborough and used to produce variants with changes in key amino acids proposed to be involved in energy conservation. Growth studies of the modified strains combined with activity assays with isolated protein variants reconstituted in proteoliposomes revealed the essential role of key amino acids involved in the MK-binding site on the P-side of the membrane, and as part of a proposed proton uptake channel from the cytoplasm to the MK-binding site. The results support the proposed model for energy conservation where, upon formate or hydrogen oxidation, QrcABCD is involved in a redox-loop mechanism with another membrane complex, generating pmf by proton and electron uptake from different sides of the membrane, without active proton pumping.
- Deep Eutectic SystemsPublication . Amador, Sandro; Martins, Alice; Matias, Margarida; Pedrosa, Rui; Pinteus, Susete; CENIMAT-i3N - Centro de Investigação de Materiais (Lab. Associado I3N); DCM - Departamento de Ciência dos Materiais; Instituto de Tecnologia Química e Biológica António Xavier (ITQB); MDPI - Multidisciplinary Digital Publishing InstituteThe extraction of bioactive compounds from marine natural products has gained increasing attention due to their diverse applications, such as in pharmaceuticals, nutraceuticals, and cosmetics. Yet, low extraction yields and toxicity associated with common solvents are a major bottleneck. Deep eutectic solvents (DESs) and natural deep eutectic solvents (NADESs) have emerged as promising green alternatives to conventional organic solvents, offering advantages such as biodegradability, greater environmental and economic sustainability, low toxicity, and enhanced extraction selectivity. This review provides a comprehensive analysis of the principles, physicochemical properties, and applications of DESs/NADESs to obtain bioactive compounds from marine organisms. Among the most recent works, it is possible to verify the success of NADESs to extract carrageenan from the seaweed Kappaphycus alvarezii; pigments from Palmaria palmata; and polyphenols and proteins from different brown seaweeds. NADESs have also shown high potential to extract other valuable compounds from marine by-products, such as chitin from crabs and shrimp shells, and also lipids and proteins from different fish species and protein rich extracts from tilapia viscera. The challenges for DESs/NADESs use at industrial scale are also discussed, and success cases are revealed, highlighting their potential as game changers for extracting bioactive compounds from marine organisms and driving the development of innovative biotechnological products.
- Marine Antimicrobial PeptidesPublication . Magalhães, Rita; Mil-Homens, Dalila; Cruz, Sónia; Oliveira, Manuela; Instituto de Tecnologia Química e Biológica António Xavier (ITQB); MDPI - Multidisciplinary Digital Publishing InstituteThe global rise in antimicrobial resistance poses a major threat to public health, with multidrug-resistant bacterial infections expected to surpass cancer in mortality by 2050. As traditional antibiotic pipelines stagnate, novel therapeutic alternatives are critically needed. Antimicrobial peptides (AMPs), particularly those derived from marine organisms, have emerged as promising antimicrobial candidates due to their broad-spectrum activity, structural diversity, and distinctive mechanisms of action. Unlike conventional antibiotics, AMPs can disrupt microbial membranes, inhibit biofilm formation, and even modulate immune responses, making them highly effective against resistant bacteria. This review highlights the potential of marine AMPs as next-generation therapeutics, emphasizing their efficacy against multidrug-resistant pathogens and biofilm-associated infections. Furthermore, marine AMPs show promise in combating persister cells and disrupting quorum sensing pathways, offering new strategies for tackling chronic infections. Despite their potential, challenges such as production scalability and limited clinical validation remain; nevertheless, the use of new technologies and bioinformatic tools is accelerating the discovery and optimization of these peptides, paving the way for bypassing these challenges. This review consolidates current findings on marine AMPs, advocating for their continued exploration as viable tools in the fight against antimicrobial resistance.
- From Dormancy to EradicationPublication . Serrano, Susana; Grujović, Mirjana; Marković, Katarina G.; Barreto-Crespo, Maria Teresa; Semedo-Lemsaddek, Teresa; Instituto de Tecnologia Química e Biológica António Xavier (ITQB); MDPI - Multidisciplinary Digital Publishing InstituteBacterial persistence, a dormant state that enables microorganisms to survive harsh conditions, is a significant concern in food-industry settings, where traditional antimicrobial treatments often fail to eliminate these resilient cells. This article goes beyond conventional review by compiling critical information aimed at providing practical solutions to combat bacterial persisters in food production environments. This review explores the primary mechanisms behind persister cell formation, including toxin–antitoxin systems, the alarmone guanosine tetraphosphate (ppGpp), stochastic processes (in which persistence occurs as a random event), and the SOS response. Given the serious implications for food safety and quality, the authors also report a range of physical, chemical, and biological methods for targeting and eradicating persister cells. The strategies discussed, whether applied individually or in combination, offer varying levels of availability and applicability within the industry and can serve as a guide for implementing microbial contamination control plans. While significant progress has been achieved, further research is crucial to fully understand the complex mechanisms underlying bacterial persistence in food and to develop effective and targeted strategies for its eradication in food-industry settings. Overall, the translation of these insights into practical applications aims to support the food industry in overcoming this persistent challenge, ensuring safer, more sustainable food production.
- Current Biological Insights of Castanea sativa Mill. to Improve Crop Sustainability to Climate ChangePublication . Marques, Tiago; Ferreira-Pinto, Andrea; Fevereiro, Pedro; Pinto, Teresa; Gomes-Laranjo, José; Instituto de Tecnologia Química e Biológica António Xavier (ITQB); MDPI - Multidisciplinary Digital Publishing InstituteThe sustainability of agriculture is seriously threatened by climate change. In Europe, chestnut ecosystems, which are growing mainly in Mediterranean climate, are facing during summertime increasing of heat and drought stresses. These induce fragilities on trees, leading to a reduction in productivity and predisposing them to pest and disease attacks. The plasticity of chestnut species under contrasting climate is known. Understanding the specific adaptation of cultivars to different climate features is now important to anticipating climate changes. Caucasian Region is considered the origin center of chestnut (Castanea sativa), which is characterized by climatic transition from the Mediterranean to the Euro-Siberian area. Mostly, areas of chestnut are concentrated in the countries around the Mediterranean Basin, thriving in regions with humid and Pré-Atlantic bioclimates. In Portugal, more than 95% of the chestnut area is located in the Center and North side of Portugal. This is an anisohydry species, characterized by good hydroplasticity: 90% reduction in A occurs when Ψwstem drops to −1.25 MPa, and a 50% reduction in A occurs at values of −1.7 MPa. The highest fatty acid contents in chestnut chloroplasts are a-linolenic acid (18:3), ranging between 40 and 50% of the total amount and being the unsaturated/saturated 2.27 for Longal. New strategies are being investigated in order to increase tolerance against those abiotic factors in chestnut species. They include the use of innovative irrigation techniques, which can increase production 22–37%. Fertilization with silicone (Si) has been investigated to promote the tolerance of plants against heat and drought stresses. Breeding programs, mostly (in Europe) against ink disease, have been performed since the middle of the XX century to create new genotypes (such the Portuguese ColUTAD®). ClimCast, a network of orchards, was created in Portugal with the aim of responding to the new challenges facing orchards in the context of climate change.
- Towards More Nuanced Narratives in Bioeconomy Strategies and Policy Documents to Support Knowledge-Driven Sustainability TransitionsPublication . Stoye, Juliane; Schlaile, Michael P.; von Cossel, Moritz; Bertacchi, Stefano; Escórcio, Rita; Winkler, Bastian; Curran, Thomas P.; Ní Chléirigh, Laoise; Nic an Bhaird, Máire; Klakla, Jan Bazyli; Nachtergaele, Pieter; Ciantar, Hailey; Scheurich, Philipp; Lewandowski, Iris; Reinmuth, Evelyn; Instituto de Tecnologia Química e Biológica António Xavier (ITQB); Molecular Diversity Preservation International (MDPI)The bioeconomy has been discussed as a key strategy for addressing sustainability challenges, particularly regarding the transition from fossil-based to bio-based systems, in numerous national and supranational strategies and policy documents related to the bioeconomy. However, public understanding of and engagement with the bioeconomy remains limited. This is partly due to the bias of many bioeconomy strategies and policy documents towards technological solutions that tend to overlook the social, normative, and transformative dimensions of systemic change as well as the necessary knowledge. This opinion paper explores the potential of narratives as a means of communicating bioeconomy research in public policy, with the aim of addressing the communication gap between science, policy, and society. When applied in responsible and nuanced ways that acknowledge their embeddedness and context, bioeconomy (policy) narratives can support sensemaking for science communication, improve public understanding, facilitate stakeholder engagement and behavioural change. We argue that such narrative approaches can help to create narrative ‘boundary objects’ that can support more inclusive and participatory processes, enabling the co-creation of transformative knowledge for bioeconomy transitions with stakeholders as active participants. In summary, we highlight several opportunities, as well as limitations and implications, that could inform future work on bioeconomy narratives.
- Storage Time in BottlePublication . Oliveira-Alves, Sheila C.; Fernandes, Tiago A.; Lourenço, Sílvia; Granja-Soares, Joana; Silva, Andreia B.; Bronze, Maria Rosário; Catarino, Sofia; Canas, Sara; Instituto de Tecnologia Química e Biológica António Xavier (ITQB); MDPI - Multidisciplinary Digital Publishing InstituteFew studies have investigated the influence on physicochemical and phytochemical compositions during storage in the bottle of wine spirits (WSs) aged using alternative ageing technology (AAT) compared to traditional ageing technology (TAT). The aim of this study was to evaluate the effect of the bottle storage over one and four years on the evolution of chromatic characteristics (CIELab method) and physicochemical characteristics (alcoholic strength, acidity, and total dry extract), total phenolic index (TPI), low molecular weight compound contents (HPLC-DAD technique), in vitro antioxidant activities (DPPH, FRAP, and ABTS assays), and phenolic characterisation (HPLC-DAD-ESI-MS/MS technique) of WSs aged with chestnut wood using TAT (barrels, B) and AAT (micro-oxygenation levels (MOX): O15, O30, and O60; and control (N)). The results showed that after four years of storage in the bottle, the O60 modality resulted in smaller changes in physicochemical characteristics, higher preservation of phenolic content, and greater evolution of chromatic characteristics, ensuring its overall quality compared to other modalities. Antioxidant activity decreased similarly in both technologies, such as phenolic acid content, in particular, gallic acid content. According to the findings of this study, alternative ageing technology might be the best alternative for wine spirit quality and ageing process sustainability.
- Role of Native Arbuscular Mycorrhizal Fungi in Modulating Nutrient Subcellular Distribution in Wheat Grown in Mn-Toxic SoilPublication . Faria, Jorge Miguel Silva; Pinto, Ana Paula; Barrulas, Pedro; Brito, Isabel; Teixeira, Dora M.; Bioresources 4 Sustainability (GREEN-IT); MDPI - Multidisciplinary Digital Publishing InstituteHeavy metal toxicity leads to impaired crop growth and reduced crop yields and product quality by disrupting plant nutrient uptake, inhibiting development, inducing oxidative stress, and causing cellular toxicity. Arbuscular mycorrhizal fungi (AMF) can play a crucial role in crops’ adaptation to manganese (Mn) toxicity by regulating nutrient uptake and altering subcellular compartmentalization. The present study examines the influence of intact extraradical mycelia (ERMs) from native AMF on wheat (Triticum aestivum) grown in Mn-toxic soil, with a focus on the tissue-specific and subcellular Ca, Mg, P, and Mn distribution. Wheat cultivated in soil pre-colonized using an intact ERM associated with Lolium rigidum or Ornithopus compressus exhibited enhanced growth and improved P contents. During the first week of growth, the Mn concentrations increased in the wheat’s roots and shoots, but Mn was subsequently reduced and sequestered within the cell wall. In contrast, in the absence of an intact ERM, the Mn accumulation in wheat followed an apparent continuous time-course pattern. AMF-mediated cell wall sequestration seems to contribute to Mn detoxification by limiting excessive cytoplasmic accumulation. Furthermore, AMF-driven changes in the element distribution suggest a dynamic response, wherein an early-stage nutrient uptake transitions into a long-term protective mechanism. These findings highlight the potential of AMF in mitigating Mn stress in crops, providing insights for sustainable agriculture and soil remediation strategies.
- Potential of Different Eighteen Grapevine Genotypes to Produce Wines in a Hot RegionPublication . Caldeira, Ilda; Roque, Rita; Anjos, Ofélia; Lourenço, Sílvia; de Deus, João; Damásio, Miguel; Silvestre, José; Bioresources 4 Sustainability (GREEN-IT); MDPI - Multidisciplinary Digital Publishing InstituteA major challenge for the viticulture and oenology sector is to understand the impact of climate change on grapevine agronomic performance and wine quality. Genetic variability offers a key tool for adaptation, as some grape varieties may better withstand changing conditions while maintaining wine quality. As part of the WineClimAdapt research project (PDR2020-101-031010), a study was conducted on the adaptability of 18 white grape varieties to hot and dry conditions in Portugal. These grape varieties from Herdade do Esporão (Alentejo, Portugal) were vinified in duplicate at the INIAV winery, the result being 36 wines. The wines underwent physicochemical and sensory analyses, including gas chromatography–mass spectrometry (GC-MS) and gas chromatography–flame ionization detection (GC-FID), to assess their composition and sensory profiles. Tasters evaluated the wines using a structured scale (0–10) and rated their overall quality (0–20). Results from analysis of variance (ANOVA) revealed significant differences in the physicochemical composition and sensory profiles of the wines. Notably, some white wines displayed high acidity, which is advantageous for hot regions. The study also highlighted clear varietal differentiation across physicochemical, volatile and sensory analyses. Among the tested varieties, “Cayetana Blanca” and “Fernão Pires” achieved the highest average quality ratings, indicating promising potential for future studies and adaptation to climate change.