CBQF - Contribuições em Revistas Científicas / Contribution to Journals
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- 1,3-Propanediol production in a two-step process fermentation from renewable feedstockPublication . Mendes, Filipa Soares; González-Pajuelo, Maria; Cordier, Hélène; François, Jean M.; Vasconcelos, IsabelIn this work, the production of 1,3-propanediol from glucose and molasses was studied in a two-step process using two recombinant microorganisms. The first step of the process is the conversion of glucose or other sugar into glycerol by the metabolic engineered Saccharomyces cerevisiae strain HC42 adapted to high (>200 g l−1) glucose concentrations. The second step, carried out in the same bioreactor, was performed by the engineered strain Clostridium acetobutylicum DG1 (pSPD5) that converts glycerol to 1,3-propanediol. This two-step strategy led to a flexible process, resulting in a 1,3-propanediol production and yield that depended on the initial sugar concentration. Below 56.2 g l−1 of sugar concentration, cultivation on molasses or glucose showed no significant differences. However, at higher molasses concentrations, glycerol initially produced by yeast could not be totally converted into 1,3-propanediol by C. acetobutylicum and a lower 1,3-propanediol overall yield was observed. In our hand, the best results were obtained with an initial glucose concentration of 103 g l−1, leading to a final 1,3-propanediol concentration of 25.5 g l−1, a productivity of 0.16 g l−1 h−1 and 1,3-propanediol yields of 0.56 g g−1 glycerol and 0.24 g g−1 sugar, which is the highest value reported for a two-step process. For an initial sugar concentration (from molasses) of 56.2 g l−1, 27.4 g l−1 of glycerol were produced, leading to 14.6 g l−1 of 1.3-propanediol and similar values of productivity, 0.15 g l−1 h−1, and overall yield, 0.26 g g−1 sugar.
- 16S-rRNA-Based metagenomic profiling of the bacterial communities in traditional Bulgarian sourdoughsPublication . Baev, Vesselin; Apostolova, Elena; Gotcheva, Velitchka; Koprinarova, Miglena; Papageorgiou, Maria; Rocha, João Miguel; Yahubyan, Galina; Angelov, AngelSourdoughs (SDs) are spontaneously formed microbial ecosystems composed of various species of lactic acid bacteria (LAB) and acid-tolerant yeasts in food matrices of cereal flours mixed with water. To date, more than 90 LAB species have been isolated, significantly impacting the organoleptic characteristics, shelf life, and health properties of bakery products. To learn more about the unique bacterial communities involved in creating regional Bulgarian sourdoughs, we examined the metacommunities of five sourdoughs produced by spontaneous fermentation and maintained by backslopping in bakeries from three geographic locations. The 16S rRNA gene amplicon sequencing showed that the former genus Lactobacillus was predominant in the studied sourdoughs (51.0–78.9%). Weissella (0.9–42.8%), Herbaspirillum (1.6–3.8%), Serratia (0.1–11.7%), Pediococcus (0.2–7.5%), Bacteroides (0.1–1.3%), and Sphingomonas (0.1–0.5%) were also found in all 5 samples. Genera Leuconostoc, Enterococcus, Bacillus, and Asaia were sample-specific. It is interesting to note that the genus Weissella was more abundant in wholegrain samples. The greatest diversity at the species level was found in the former genus Lactobacillus, presented in the sourdough samples with 13 species. The UPGMA cluster analysis clearly demonstrated similarity in species’ relative abundance between samples from the same location. In addition, we can conclude that the presence of two main clusters—one including samples from mountainous places (the cities of Smolyan and Bansko) and the other including samples from the city of Ruse (the banks of the Danube River)—may indicate the impact of climate and geographic location (e.g., terrain, elevation, land use, and nearby water bodies and their streams) on the abundance of microbiome taxa. As the bacterial population is crucial for bread standardization, we expect the local bakery sector to be interested in the relationship between process variables and their effect on bacterial dynamics described in this research study.
- 2-Arachidonoylglycerol impairs human cytotrophoblast cells syncytialization: influence of endocannabinoid signalling in placental developmentPublication . Costa, M. A.; Keating, E.; Fonseca, B. M.; Teixeira, N. A.; Correia-da-Silva, G.A balanced cytotrophoblast cell turnover is crucial for placental development and anomalies in this process associated with gestational diseases. The endocannabinoid system (ECS) has emerged as a new player in several biological processes. However, its influence during placental development is still unknown. We report here the expression of the endocannabinoid 2-arachidonoylglycerol (2-AG) main metabolic enzymes in human cytotrophoblasts and syncytiotrophoblast. We also showed that 2-AG induced a decrease in placental alkaline phosphatase activity, human chorionic gonadotropin secretion and Leptin mRNA levels. Moreover, 2-AG reduced glial cell missing 1 and syncytin-2 transcription and the number of nuclei in syncytium. These effects were mediated by cannabinoid receptors and may result from 2-AG inhibition of the cAMP/PKA signalling pathway. Our data suggest that 2-AG may interfere with the biochemical and morphological differentiation of human cytotrophoblasts, through a CB receptor-dependent mechanism, shedding light on a role for the ECS in placental development.
- 2-Fluorophenol degradation by aerobic granular sludge in a sequencing batch reactorPublication . Duque, Anouk F.; Bessa, Vânia S.; Carvalho, Maria F.; Kreuk, Merle K. de; Loosdrecht, Mark C. M. van; Castro, Paula M. L.Aerobic granular sludge is extremely promising for the treatment of effluents containing toxic compounds, and it can economically compete with conventional activated sludge systems. A laboratory scale granular sequencing batch reactor (SBR) was established and operated during 444 days for the treatment of an aqueous stream containing a toxic compound, 2-fluorophenol (2-FP), in successive phases. Initially during ca. 3 months, the SBR was intermittently fed with 0.22 mM of 2-FP added to an acetate containing medium. No biodegradation of the target compound was observed. Bioaugmentation with a specialized bacterial strain able to degrade 2-FP was subsequently performed. The reactor was thereafter continuously fed with 0.22 and 0.44 mM of 2-FP and with 5.9 mM of acetate (used as co-substrate), for 15 months. Full degradation of the compound was reached with a stoichiometric fluoride release. The 2-FP degrading strain was successfully retained by aerobic granules, as shown through the recovering of the strain from the granular sludge at the end of the experiment. Overall, the granular SBR has shown to be robust, exhibiting a high performance after bioaugmentation with the 2-FP degrading strain. This study corroborates the fact that bioaugmentation is often needed in cases where biodegradation of highly recalcitrant compounds is targeted.
- 2023 outstanding papers published in the Environmental Science journals of the Royal Society of ChemistryPublication . Cai, Zongwei; Donahue, Neil; Gagnon, Graham; Jones, Kevin C.; Manaia, Célia; Sunderland, Elsie; Vikesland, Peter J.
- 2023 outstanding papers published in the Environmental Science journals of the Royal Society of ChemistryPublication . Cai, Zongwei; Donahue, Neil; Gagnon, Graham; Jones, Kevin C.; Manaia, Célia; Sunderland, Elsie; Vikesland, Peter J.
- # 29. Saúde oral e seus determinantes na população escolar de 6‐10 anos em Nampula – MoçambiquePublication . Barroso, João Pedro; Pereira, Diogo Ribeiro Castro; Saíde, Alarquia Aly; Pires, Isabel; Rêgo, Carla; Pereira, Maria de Lurdes LoboObjetivos: Avaliar a saúde oral e os hábitos associados em crianças com idades compreendidas entre os 6‐10 anos, residentes nas regiões urbana e rural de Nampula – Moçambique. Materiais e métodos: Trezentas e oitenta e uma crianças de 4 escolas (2 rurais e 2 urbanas). Estudo transversal, com aplicação de questionário para a avaliação de comportamentos relacionados com a saúde oral, exame clínico intraoral e levantamento de dados antropométricos. Foi efetuada uma análise estatística descritiva e inferencial, através do T‐test e do qui‐quadrado de Pearson. Resultados: A idade média (dp) das crianças foi de 8,4 (1,4) anos. Regista‐se uma prevalência de 13,1% de excesso ponderal. A ingestão de alimentos cariogénicos, quer de origem tradicional, quer processados, é elevada e transversal ao longo do dia (89,5% à refeição, 98,2% ao lanche e 75,9% à ceia), sem diferença na dependência da zona de residência. A prevalência de cárie foi de 71,3%. A média (dp) de cpod/CPOD foi de 3,58 (3,84) registando‐se um valor de cpod de 2,19 (2,18) e de 1,39 (1,84) para CPOD. A média (dp) para o HIO‐S foi de 1,54 (0,79). O uso de pasta dentífrica foi significativamente mais frequente nas crianças da região urbana (p ≤ 0,001), e o recurso a métodos tradicionais de escovagem (mulala, carvão, eraque) nas crianças da zona rural (p< = 0,001). Não se observou qualquer tratamento dentário. Conclusões: Registaram‐se índices de cárie e de higiene oral moderados. A manutenção de métodos tradicionais de higienização oral está associada à zona de residência, concretamente à ruralidade. A inexistência de qualquer tipo de cuidados médico‐dentários preventivos ou restauradores, aliada a um padrão de elevado consumo diário de alimentos cariogénicos e a uma inadequada exposição a dentífricos fluoretados, principalmente nas zonas rurais, afiguram‐se como um mau prognóstico para a saúde oral da população estudada. Os resultados sugerem a necessidade de adoção de medidas concretas de promoção para a saúde oral na população, podendo as escolas funcionar como veículo privilegiado para a sua implementação.
- 3D printed Poly(ε-caprolactone)/Hydroxyapatite scaffolds for bone tissue engineering: a comparative study on a composite preparation by melt blending or solvent casting techniques and the influence of bioceramic content on scaffold propertiesPublication . Biscaia, Sara; Branquinho, Mariana V.; Alvites, Rui D.; Fonseca, Rita; Sousa, Ana Catarina; Pedrosa, Sílvia Santos; Caseiro, Ana R.; Guedes, Fernando; Patrício, Tatiana; Viana, Tânia; Mateus, Artur; Maurício, Ana C.; Alves, NunoBone tissue engineering has been developed in the past decades, with the engineering of bone substitutes on the vanguard of this regenerative approach. Polycaprolactone-based scaffolds are fairly applied for bone regeneration, and several composites have been incorporated so as to improve the scaffolds’ mechanical properties and tissue in-growth. In this study, hydroxyapatite is incorporated on polycaprolactone-based scaffolds at two different proportions, 80:20 and 60:40. Scaffolds are produced with two different blending methods, solvent casting and melt blending. The prepared composites are 3D printed through an extrusion-based technique and further investigated with regard to their chemical, thermal, morphological, and mechanical characteristics. In vitro cyto-compatibility and osteogenic differentiation was also assessed with human dental pulp stem/stromal cells. The results show the melt-blending-derived scaffolds to present more promising mechanical properties, along with the incorporation of hydroxyapatite. The latter is also related to an increase in osteogenic activity and promotion. Overall, this study suggests polycaprolactone/hydroxyapatite scaffolds to be promising candidates for bone tissue engineering, particularly when produced by the MB method.
- 3D-printed PLA medical devices: physicochemical changes and biological response after sterilisation treatmentsPublication . Pérez-Davila, Sara; González-Rodríguez, Laura; Lama, Raquel; López-Álvarez, Miriam; Oliveira, Ana Leite; Serra, Julia; Novoa, Beatriz; Figueras, Antonio; González, PíoPolylactic acid (PLA) has become one of the most commonly used polymers in medical devices given its biocompatible, biodegradable and bioabsorbable properties. In addition, due to PLA’s thermoplastic behaviour, these medical devices are now obtained using 3D printing technologies. Once obtained, the 3D-printed PLA devices undergo different sterilisation procedures, which are essential to prevent infections. This work was an in-depth study of the physicochemical changes caused by novel and conventional sterilisation techniques on 3D-printed PLA and their impact on the biological response in terms of toxicity. The 3D-printed PLA physicochemical (XPS, FTIR, DSC, XRD) and mechanical properties as well as the hydrophilic degree were evaluated after sterilisation using saturated steam (SS), low temperature steam with formaldehyde (LTSF), gamma irradiation (GR), hydrogen peroxide gas plasma (HPGP) and CO2 under critical conditions (SCCO). The biological response was tested in vitro (fibroblasts NCTC-929) and in vivo (embryos and larvae wild-type zebrafish Danio rerio). The results indicated that after GR sterilisation, PLA preserved the O:C ratio and the semi-crystalline structure. Significant changes in the polymer surface were found after HPGP, LTSF and SS sterilisations, with a decrease in the O:C ratio. Moreover, the FTIR, DSC and XRD analysis revealed PLA crystallisation after SS sterilisation, with a 52.9% increase in the crystallinity index. This structural change was also reflected in the mechanical properties and wettability. An increase in crystallinity was also observed after SCCO and LTSF sterilisations, although to a lesser extent. Despite these changes, the biological evaluation revealed that none of the techniques were shown to promote the release of toxic compounds or PLA modifications with toxicity effects. GR sterilisation was concluded as the least reactive technique with good perspectives in the biological response, not only at the level of toxicity but at all levels, since the 3D-printed PLA remained almost unaltered.
- Access to information, and concerns, myths and truths about food safety during the COVID-19 pandemic: an overview of the Portuguese populationPublication . Lemos, Marcela; Maia, Rui Leandro; Teixeira, PaulaThe COVID-19 pandemic raised questions and concerns about the possibility of the virus being transmitted through food, as the virus was found in sewage, shrimps and packages of frozen food. During the first wave of COVID-19, concerns about the transmission of SARS-CoV-2 through food arose. As the number of cases began to increase rapidly, so did the availability of information regarding the virus and ways to prevent infection. A significant portion of this information was disseminated by the media and the general public. Identifying and understanding the main doubts and concerns about food hygiene and safety raised by the Portuguese population during the first wave of COVID-19 is important in order to understand whether these issues have influenced their practices and what lessons can be learnt for food safety and hygiene education. The aims of this work were (1) to understand the doubts and concerns of the Portuguese population regarding food safety and hygiene during the first wave of COVID-19, and how these issues were clarified, (2) to analyze the population’s opinion on food/hygiene myths and truths related to the transmission and prevention of the infection, and (3) to understand how the first wave of COVID-19 may have influenced the population’s practices linked to food handling and consumption. The main doubts of the respondents were related to food handling (41.6%) and the possibility of transmission of COVID-19 through food (17%). Television was the main source of information used to clarify these doubts (32.9%), followed by a guideline issued by the Directorate-General of Health (30.7%). However, most respondents (50.9%) said that they had only found answers to some of their questions. Most respondents reported washing and disinfecting hands before (85% and 63.4%, respectively) and after (73.8% and 57.3%, respectively) the handling and organization of food purchases. Most respondents did not believe the myths about COVID-19 and food safety, but this depended on their level of education. Some practices may have changed as a result of the pandemic, particularly with regard to washing and disinfecting hands and food, as well as kitchen hygiene.