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Anaerobic digestion of different feedstocks: impact on energetic and environmental balances of biogas process
1000 | 2013
Bacenetti, Jacopo | Negri, Marco | Fiala, Marco | González-García, Sara
The possibility of limiting the global warming is strictly linked to the reduction of GHG emissions. Renewable energy both allows reducing emissions and permits to delay fossil fuel depletion. The anaerobic digestion of animal manure and energy crops is a promising way of reducing GHG emissions. In Italy agricultural biogas production was considerably increased; nowadays there are about 520 agricultural biogas plants.The increasing number of biogas plants, especially of those larger than 500kWe(electrical power), involves a high consumption of energy crops, large transport distances of biomass and digestate and difficulties on thermal energy valorization.In this study the energetic (CED) and environmental (GHG emissions) profiles associated with the production of electricity derived from biogas have been identified. Three biogas plants located in Northern Italy have been analyzed. The study has been carried out considering a cradle-to-grave perspective and thus, special attention has been paid on the feedstock production and biogas production process. The influences on the results taking into account different plant sizes and feeding rate has been assessed in detail.Energy analysis was performed using the Cumulative Energy Demand method (CED). The climate change was calculated for a 100-year time frame based on GHG emissions indicated as CO2equivalents (eq) and defined by the IPCC (2006).In comparison to the fossil reference system, the electricity production using biogas saves GHG emissions from 0.188 to 1.193kgCO2eq per kWhe. Electricity supply from biogas can also contribute to a considerable reduction of the use of fossil energy carriers (from -3.97 to 10.08MJfossilper kWhe). The electricity production from biogas has a big potential for energy savings and reduction of GHG emissions. Efficient utilization of the cogenerated heat can substantially improve the GHG balance of electricity production from biogas.
Показать больше [+] Меньше [-]Life cycle assessment of pigmeat production: portuguese case study and proposal of improvement options
1000 | 2015
González-García, Sara | Belo, Sara | Dias, Ana Cláudia | Rodrigues, João Várzea | da Costa, Rosário Roberto | Ferreira, António | de Andrade, Luís Pinto | Arroja, Luis
The aim of this study was to provide a detailed environmental evaluation of pigmeat production (the second most widely eaten type of meat) in Portugal, using relevant and good quality data in order to obtain representative results for this production sector. Life cycle assessment (LCA) methodology was used for the evaluations from a cradle-toslaughterhouse gate perspective. The system under study was divided in three subsystems: crop and feed production (S1), pigmeat production (S2) and slaughtering (S3). The production system under study considered the Best Available Techniques (BATs) for intensive rearing of pigs. According to the results and in line with other studies, S1 was the most influential subsystem in the environmental profile (ranging from 70% to 100% depending on the impact) mainly due to agricultural activities involved in the production of feed components. Activities carried out on the pig farms (S2) were remarkable in categories such as climate change due to background processes involved in the production of electricity requirements, e.g. emissions derived from slurry management (such as CH4 and N2O), and water depletion. Slaughtering-related contributions were negligible regardless of the category assessed. Different alternatives for the valorisation of animal by-products derived from the slaughterhouse were proposed for energy and feed production. A comparison with other related studies focused on pigmeat production was performed and no remarkable differences were identified. Thus, achievements and environmental hotspots identified in this specific case study for Portugal could be extended to the European production chain.
Показать больше [+] Меньше [-]The role of early fungal colonizers in leaf-litter decomposition in Portuguese streams impacted by agricultural Runoff
1000 | 2009
Sridhar, K. R. | Duarte, Sofia Alexandra Ferreira | Cássio, Fernanda | Pascoal, Cláudia
We conducted a transplant experiment between two streams in NW Portugal impacted by agricultural runoff, mainly differing in phosphate concentration, to determine whether fungi on decomposing leaves would adapt to the new environment or would be replaced by fungi of the recipient stream. The most nutrient enriched stream had lower fungal diversity but faster leaf decomposition. Leaf transplantation did not alter fungal activity or species dominance. Multidimensional scaling ordination of fungal communities, from DNA fingerprint or conidial production, revealed that transplanted communities resembled more those of the original stream than the recipient stream. Results suggest that early fungal colonizers will determine the development and activity of fungal communities on decomposing leaves in streams impacted by agricultural practices. | Portuguese Foundation for the Science and Technology (SFRH/BD/13482/2003)
Показать больше [+] Меньше [-]Comparative life cycle assessment of three representative feed cereals production in the Po Valley (Italy)
1000 | 2015
Noya, Isabel | González-García, Sara | Bacenetti, Jacopo | Arroja, Luís | Teresa Moreira, Maria
The cultivation of three different cereals e wheat, triticale and maize (five classes: 300, 400, 500, 600 and 700) e dedicated to grain production for feed purposes was assessed to quantify their environmental profiles and identify the most sustainable crop from an environmental perspective. The most critical processes throughout the life cycle of the cropping systems were also identified. These cereals were chosen because they are the most widespread cereal crops in the Po Valley (Lombardy region), the most important agricultural area in Italy. The standard framework of the Life Cycle Assessment (LCA) was followed to assess the environmental performance of the different cropping systems. Several impact categories were evaluated, including climate change (CC), ozone depletion (OD), terrestrial acidification (TA), freshwater eutrophication (FE), marine eutrophication (ME), human toxicity (HT), photochemical oxidant formation (POF), terrestrial ecotoxicity (TEC), freshwater ecotoxicity (FEC), marine ecotoxicity (MEC), water depletion (WD), fossil depletion (FD) as well as land use as an indicator. The results showed that the maize class 300 was the cereal with the worst environmental profile in the base case, considering economic allocation and no environmental burdens related with digestate production. This scenario presented the most intensive agricultural practices and the lowest biomass yield in comparison with the other crops. In contrast, the maize classes 600 and 700 were the cereal crops with the best environmental profiles in most impact categories. The lower requirements of fertiliser (and thus, fertilisation activities) as well as the higher biomass yield were responsible of these favourable results. However, according to the environmental results, the selection of the best biomass source depends on several methodological assumptions such as the functional unit and the allocation criteria considered (between the grain and the straw) as base for the calculations. Thus, the results of a sensitivity analysis showed that the choice of a mass allocation instead of economic one caused lower environmental impacts in all the categories. Moreover, the consideration or not of the environmental burdens related to the digestate production (the main organic fertiliser used) was also a critical step in the environmental evaluations. The inclusion of environmental loads related to digestate production caused a notable increase in the impact of all the cropping systems regardless the cereal and the impact category. This conclusion could be extrapolated to other systems that exclude the additional burdens allocated to the production of organic fertilisers.
Показать больше [+] Меньше [-]Biotechnological valorization of oilseed cakes: Substrate optimization by simplex centroid mixture design and scale-up to tray bioreactor
1000 | 2023
Sousa, D. F. | Salgado, José Manuel | Cambra-López, Maria | Dias, Alberto | Belo, Isabel
Sunflower (SFC), rapeseed (RSC), and soybean cakes (SBC) are examples of oilseed cakes (OC) used in animal feed. Bioprocessing of these OC by solid-state fermentation (SSF) aims to boost OC applications in feed and other industries by reducing antinutritional factors and releasing enzymes and antioxidants. A simplex centroid design was performed to optimize the substrate composition of SFC, RSC and SBC mixtures that maximize lignocellulolytic enzymes production by SSF with Aspergillus niger and consequently improve the nutritional properties of OC. Enzyme production by SSF of OC mixtures exceeded the activity values obtained using a single oilseed cake. A mixture composed of 50% (w/w) RSC and SBC was found to be the optimum substrate. The scale-up from flasks to tray-type bioreactors demonstrated SSF reproducibility, leading to the production of 299 U g1 cellulase, 1476 U g1 xylanase, 191 U g1 -glucosidase and 220 U g1 protease. The obtained enzymatic extract also presented antioxidant activity (around 50 mol Trolox equivalents/g). This study demonstrated that bioprocessing of OC mixtures through SSF is an effective approach to obtain value-added products with applications as feed or feed additives and to increase the liberation of bioactive compounds with applications in the feed, food, cosmetic and pharmaceutical industries. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd. | The authors thank the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/BIO/04469/2020 and UIDB/04033/2020 units. Daniel Sousa acknowledges the financial support provided by national funds through FCT (PD/BD/135328/2017), under the Doctoral Program ‘Agricultural Production Chains – from fork to farm’ (PD/00122/2012) and from the European Social Funds and the Regional Operational Programme Norte 2020. | info:eu-repo/semantics/publishedVersion
Показать больше [+] Меньше [-]Phaseolus vulgaris L. as a functional food for aging protection
1000 | 2020
Santos, Eunice | Marques, Guilhermina | Lino-Neto, T.
The common bean (Phaseolus vulgaris L.) is the most consumed legume and the major protein source for poor populations, especially in developing Afro-Asian countries. Common bean has a high nutritional value, being rich in protein, carbohydrates, essential fatty acids, vitamins, minerals, and fibers. Besides these nutrients, common bean is also enriched in bioactive compounds, such as polyphenols, mainly flavonoids. These compounds reveal important antioxidant activities through their capacity to interfere with oxidative processes and consequently exhibit antiinflammatory activity. Common bean also reveals anticarcinogenic and antimutagenic activities. Accordingly the consumption of common bean has been associated with the prevention and control of several age-related problems, such as diabetes, obesity, cardiovascular and gastrointestinal diseases, and cancer. This chapter focuses on the bioactivities present in common bean grains that make this legume an excellent functional food. Therefore the increase in common bean consumption, in traditional or nutraceutical forms, should be encouraged for improving human health. | This work was financed by Portuguese national funds through Programa Operacional Competitividade e Internacionalização (POCI), Project 3599, Promover a Produção Científica e Desenvolvimento Tecnológico e a Constituic¸ão de Redes Temáticas (3599-PPCDT) and Fundo Europeu de Desenvolvimento Regional (FEDER) under Project POCI-01-0145-FEDER-016801, by FCT under projects PTDC/AGR-TEC/1140/2014 and by FCT/MCTES/PIDDAC (Portugal) under the projects UID/MULTI/04046/2013, UID/AGR/04033/2013, and POCI-01-0145-FEDER-006958. The first author also acknowledges the financial support provided by the European Social Funds and the Regional Operational Programme Norte 2020 (operation NORTE-08-5369-FSE-000054) under the doctoral program “Agricultural Production Chains, from fork to farm” (PD/00122/2012).
Показать больше [+] Меньше [-]Yeasts as new powerful bio-tools for sustainable agriculture: Biocontrol of plant fungal diseases and ecological implications
1000 | 2023
Lucas, Cândida | Cássio, Fernanda
Crop diseases caused by fungi or oomycetes are responsible for significant losses in food production worldwide, and are increasingly recognized as a global threat to food security. This crisis derives from concurring factors, which include agricultural practices, global trade and climate change, all of which synergistically impact plants’ fitness, critical to the maintenance of function and services of agro-ecosystems. Yeasts are part of the plant holobiont, in the phytosphere, rhizosphere and adjacent soil, where they play mostly unknown roles, which do not include damage or disease to plants. In other respects, yeasts have beneficial potential for the biological control of fungal diseases and as promoters of plant health and growth. Their roles as endophytes, mutualists and as part of roots and soils microbiome are presented and discussed in this chapter, as are the ways by which yeasts kill fungi. These include the secretion of Killer toxins, hydrolytic enzymes, small peptides, siderophores and/or VOCs. Some species also act as necrotrophic mycoparasites. Yeasts’ resilience in face of environmental stress, specificity of action and amenability towards plants and humans, together with their fast proliferation, make them significant candidates for utilization in sustainable agriculture practices, both as BCAs and PGPs, urging research in this regard. | We thank Sofia Costa, a senior researcher at our research centre, for her critical reading and suggestions. This work was supported (i) by the “Contrato-Programa” UIDB/04050/2020 funded by national funds through the FCT I.P.; (ii) by the Fundação para a Ciência e Tecnologia (FCT), under the project LA/P/0069/2020 granted to the Associate Laboratory ARNET; and (iii) by the FCT, CCDR-NCCDR-N (Norte Portugal Regional Coordination and Development Commission) and European Funds (FEDER/POCI/COMPETE2020) through the project AgriFoodXXI (NORTE 01-0145-FEDER-000041).
Показать больше [+] Меньше [-]Microalgae and cyanobacteria as sources of bioactive compounds for cosmetic applications: A systematic review
1000 | 2023
Castro, Vera | Oliveira, Rui Pedro Soares de | Dias, Alberto Carlos Pires
Microalgae and cyanobacteria are rich in compounds with a wide diversity of biological activities that can be used to create new products with promising applications by the cosmetic industry. Many studies evaluating the bioactivities of microalgae and cyanobacteria extracts have been published, however perception of their potential use in cosmetic applications is still limited. The objective of this study was to systematically review the recent literature to assess the potential applications of microalgae and cyanobacteria in cosmetics. A total of 8498 articles mentioning antioxidant or anti-inflammatory properties, or cosmetic or nanosystem applications of microalgae and cyanobacteria extracts or biomass in the past 5 years were retrieved from different databases and the eligibility process was conducted applying inclusion and exclusion criteria. After that, 151 papers were selected of which 61 % cited antioxidant properties, 19 % cosmetic applications, 14 % anti-inflammatory potential, and 6 % nanosystem applications. The most reported genera were Chlorella (7 %), Arthrospira (7 %), Tetraselmis and Scenedesmus (6 % each). Crude extracts or biomass (56 %), pigments (14 %) and polysaccharides (9 %) were the type of microalgae- and cyanobacteria-based products most reported, Ninety-six percent of articles used in vitro methods with in vitro non-cellular assays being most cited (79 %) when compared with cellular assays (21 %), and only 4 % used in vivo approaches. Considering cosmetic applications, photoprotection (43 %), anti-cancer (melanoma) (19 %), and wound healing (16 %) were the most reported. A limited number of studies reported nanosystem applications, with metal nanoparticles and nanoemulsions as the most common nanosystem. The evidence found in the literature suggest that microalgae and cyanobacteria extracts are rich sources of bioactive products and compounds for cosmetic industry, which potential is far from being fully explored. | The authors acknowledge the financial support provided by the FCT Portuguese Foundation for Science and Technology (PD/BD/150264/2019) under the Doctoral Programme “Agricultural Production Chains – from fork to farm” (PD/00122/2012) and the Financiamento Plurianual de Unidades de I&D UIDB/04050/2020. This work was also supported by the “Contrato-Programa” UIDB/04050/2020 funded by national funds through the FCT I.P. This work was also funded by POCI-01-0247- FEDER-033784, Project Nº 33784, Extratoteca – Extratos de Microalgas com Elevado Valor-Acrescentado.
Показать больше [+] Меньше [-]Chronic effects of realistic concentrations of non-essential and essential metals (Lead and Zinc) on oxidative stress biomarkers of the mosquitofish, Gambusia holbrooki
1000 | 2015
Nunes, Bruno | Caldeira, Carina | Pereira, Joana Luísa | Gonçalves, Fernando | Correia, Alberto Teodorico
Metallic contamination is widespread, particularly in areas impacted by human activities. Human activities result in high loads of metals being discarded into the aquatic compartment, reinforcing the need to evaluate their toxic effects especially on exposed fish. The purpose of this study was to determine the toxic response (namely, antioxidant levels and lipoperoxidative damage) in both liver and gills of the freshwater fish species Gambusia holbrooki, exposed to lead and zinc. Fish were exposed for 28 days (chronic exposure) to ecologically relevant concentrations of the selected compounds. The following oxidative stress/damage biomarkers were evaluated: glutathione-S-transferases (GSTs), glutathione reductase (GR), and thiobarbituric acid reactive substances (TBARS). The results indicate that lead caused a significant oxidative response, with significant increase of the enzymatic antioxidant defense (GSTs activity in hepatic tissue, and GR activity in branchial tissue) of exposed organisms. On the other hand, zinc caused a significant inhibition of G. holbrooki hepatic GR, a biological response that may be related to the antioxidant activity exhibited by this metal. The obtained results are of high importance, especially if one considers that the obtained toxic responses occurred at low, albeit ecologically relevant, levels of exposure. Metal-containing waste (from domestic, agricultural and industrial sources) that is continuously released can have significant impacts on the environment, particularly aquatic ecosystems (López-Galindo et al. 2010). In recent years, the effects of metallic pollution in fish were demonstrated, showing that these organisms are able to bioaccumulate these pollutants (Greco et al. 2010). In addition, metals can induce severe alterations, including an oxidative stress response in various cell types, and also significant alterations of the elimination profile of foreign molecules from the body (Wang et al. 2009; Johnston et al. 2010). Thus, oxidative stress biomarkers, and others (especially those implicated in the metabolism of toxic molecules), have become an important assessment tool in aquatic toxicology (Livingstone 2001; Wang et al. 2009; Jin et al. 2010; Johnston et al. 2010) to monitor the occurrence of pollutants, and deleterious effects potentially exerted in aquatic organisms. The use of molecular oxygen in normal respiratory processes in mitochondria results in the physiological production and release of reactive oxygen species (ROS; Chance et al. 1979; Wallace 1999); exposure to xenobiotics (including metals) can increase the production of ROS through several mechanisms, such as interference in the electron transport within the mitochondrial membrane and subsequent accumulation of reactive intermediates (Herrero et al. 2008). This may result in cellular damage, namely by inactivation of antioxidant enzymes, depletion of nonenzymatic antioxidants, and membrane lipid peroxidation (Modesto and Martinez 2010). The review by Franco et al. (2009) referenced that some of the most common environmental contaminants, including several metallic species (e.g., iron, copper, chromium, cobalt, vanadium, cadmium, arsenic, nickel), could trigger apoptosis through the interference with regulating cellular mechanisms. Metals are known to interfere at several subcellular levels, such as the mitochondria (oxidation of mitochondrial RNA, and activation of the intrinsic apoptotic pathway), the endoplasmatic reticulum, and nuclear DNA. Moreover, established oxidative imbalance can cause irreversible oxidative damage in DNA and other macromolecules, or even death of organisms (Jin et al. 2010; Li et al. 2010; Modesto and Martinez 2010). ROS are removed or inactivated by antioxidant defenses, and the balance between these radicals and the antioxidant defense of living organisms is fundamental for their protection against oxidative stress and its deleterious consequences (Li et al. 2010; Modesto and Martinez 2010). Nevertheless, the exposure to chemical pollutants also may contribute to oxidative stress, by altering this equilibrium, and consequently inducing a decrease in the antioxidant defense system efficiency (Solé et al. 1996; Livingstone 2001). Fish cope with the harmful effects of oxidative stress through adaptive responses, namely by increased activity of enzymes involved in the biotransformation and metabolism of a wide range of environmental contaminants and their metabolites (Ognjanovic et al. 2008; Modesto and Martinez 2010). The antioxidant defense system of the majority of organisms is composed by a multitude of enzymes, among which it is possible to identify glutathione reductase (GR), and glutathione-S-transferases (GSTs). These are the most frequently studied biomarkers of oxidative stress in fish (Jin et al. 2010; Modesto and Martinez 2010; Pereira et al. 2010). Lipoperoxidation (LPO) estimation also has been found to have a high value as a biomarker of toxic effects, because this parameter reflects the onset of cellular damage, as a result of oxidation of membrane lipids (Ognjanovic et al. 2008; Pereira et al. 2010). Amongst all compounds present in the environment, in growing amounts and with evident human origin, metals are particularly important. Metals are widely dispersed in the aquatic environment, being released by anthropogenic activities (mining, release of domestic products into sewage; plumbing degradation; emissions from nuclear plants, from smelters and from burning fossil fuels) but also by natural sources (e.g., volcanoes) (Hozhina et al. 2001; Thompson et al. 2005; Rose and Shea 2007; Connan and Tack 2010; Aktar et al. 2011). Metallic species are fundamental for life, being part of macromolecules and enzymes (Liu and Thiele 1997). However, metals also are prone to establish redox cycles if in the presence of molecular oxygen, giving rise to the production of ROS (Herrero et al. 2008). Consequently, metals are dual in their effects: albeit vital, they are eminently toxic (Liu and Thiele 1997). Metals (especially transition metals) are toxic and capable of exerting important deleterious effects of oxidative nature in exposed organisms, as reviewed by Valavanidis et al. (2006). Metals, such as arsenic, cadmium, lead, mercury, chromium, nickel, manganese, and iron, especially in their waterborne form, can indeed increase the production of reactive oxygen species (Jadhav et al. 2007). However, exposure to metals conducing to oxidative stress is commonly followed by a set of immediate physiological adaptations (e.g., through antioxidant defenses) to prevent their adverse effects. For example, the study conducted by Grinevicius et al. (2009) on textile effluents rich in metallic species evidenced antioxidant responses in the freshwater fish Danio rerio. Despite the activation of antioxidant mechanisms following chemical insults by metals, damage (e.g., lipid peroxidation) is likely to occur, as reported by Siddique et al. (2008) after exposing Drosophila melanogaster to metals present in tannery effluents. Mining effluents also were proven to induce oxidative stress responses in fish (Kelly and Janz 2009), anurans (Marques et al. 2011), and mammals (Reglero et al. 2009). The purpose of the present study was to evaluate the chronic effects induced by exposure to environmentally realistic concentrations of two metals (nonessential lead and essential zinc) on oxidative stress parameters of the freshwater fish Gambusia holbrooki. Being distinct in nature and biological effects, these two metals are dispersed widely in Portuguese estuaries (Mucha et al. 2003; Fernandes et al. 2008). However, it is important to know in detail their toxic effects when in ecologically relevant levels to ascertain about the putative common toxic mechanisms and to know the biological responses elicited by fish to cope with these two different compounds. The oxidative stress parameters GSTs, GR, and thiobarbituric acid reactive substances (TBARS) were measured in hepatic and gill tissues to serve as putative biomarkers of effect in this study, provided their role in key biological processes determinant for the survival of the individuals: the enzymes are involved in detoxification by phase II metabolism (conjugation with glutathione) and antioxidant activity, and TBARS are indicative of lipoperoxidative damage (Nunes et al. 2008, 2015a, b). As target organs, we chose liver and gills because the liver is the main organ of xenobiotic metabolism in fish, and the gills are the primary barrier against the entrance of xenobiotics into the body and also are the first line of detoxification and elimination of deleterious compounds (Wood and Soivio 1991; Evans et al. 2005).
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