Centro de Biotecnologia e Química Fina (CBQF)
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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.
- 2-Fluorophenol degradation by aerobic granules in a sequencing batch reactorPublication . Duque, A. F.; Bessa, V. S.; Carvalho, M. F.; De Kreuk, M. K.; Loosdrecht, M. C. M. van; Castro, P. M. L.
- 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 bioactive interference screw and PCL bio-filler for ligament fixationPublication . Rodrigues, Mafalda; Moreira, Rui; Silva, Inês V.; Duarte, Marta M.; Ribeiro, Viviana P.; Oliveira, Ana L.; Costa, João B.Musculoskeletal injuries, widespread across all ages, genders and sociodemographic groups, are prevalent in the knee joint and require a range of treatments - from conservative methods to surgical interventions, such as meniscal resection, repair, reconstruction or tissue engineering (TE) approaches. To address one of the most significant challenges in orthopedic procedures – long-term implant fixation – an innovative solution is being developed for knee ligaments and meniscus fixation. PLA screws are being developed through the combination of 3D printing, supercritical CO2 (scCO2) foaming and impregnation technologies, aiming to achieve a biodegradable and bioactive screw with improve bone integration ability. Additionally, to improve the anchor and fixation of the ligament treatments, PCL Bio-Fillers are being developed through the use of 3D printing, electrospinning and dipping methods with the final goal to induce the bone cells to reproduce itself (osteogenesis) and create a better grip between the ligaments and the bone. PLA screws were manufactured by 3D printing and further process to induce porosity by scCO2 foaming, followed by EPS impregnation through scCO2. Scanning electron microscopy (SEM) was used to evaluate microporosity and the EPS impregnation. The CO2 concentration, density and expansion ratio of the PLA screws were evaluated. FTIR (Fourier-transform infrared spectroscopy) was performed to evaluate chemical composition changes of the samples. DSC (Differential scanning calorimetry) was applied to analyze thermal stability both before and after treatment. PCL Bio-Fillers were produced by 3D printing, coated with PCL using electrospinning and dipped with bruxite. Then, to study the PCL fibers and bruxite dispersion, we have used the scanning electron microscopy (SEM) method. Results: Several conditions of foaming were tested (pressure, time, temperature and controlled expansion measures) and then, analyzed through SEM imaging. Samples with greater porosity were selected for further testing and analysis. The CO2 concentration results revealed that the saturation increase is proportional to the increase in pressure and inversely proportional to the increase in infill density. The expansion ratio results demonstrated that it typically decreases with increasing infill density and batch pressure. To optimize the 3D printed Bio-Fillers coated with PCL several parameters were adjusted (PCL concentration, flow rate, distance, potential difference, and nozzle size). Firstly, samples with apparent macroscopy uneven coating were remove with further analysis being performed via SEM analysis. The SEM analysis showed that increasing the potential difference and decreasing the flow rate produced more dispersed and thinner fibers. It also revealed that increase PCL concentration led to higher fiber density and size. In the end, the parameters that resulted in the better PCL fibers dispersion were with a concentration of 7,5% w/v of PCL, 20 μL/min flow rate, 10 cm of distance between the nozzle and the Bio-Filler, 23 kV of potential difference and 20 G of nozzle size. Further work is being performed to optimize the dipping process with bruxite and achieve an even coating. Conclusion: The sCO2 methodologies implemented were efficient in terms of generating porosity and EPS impregnation. EPS-induced bioactivity will be studied in the future.
- 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.