Escola Superior de Biotecnologia
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- 1,3-Propanediol continuous production by Clostridium butyricum VP1 1718: effect of dilution rate and substrate concentrationPublication . Gonzalez-Pajuelo, M.; Ribeiro-Cruz, A. P.; Sousa- Monagas, C. M.; Andrade, J. C.; Vasconcelos, I.
- 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.
- 3-Hydroxy-4,5-dimethyl-2(5H)-furanone levels in fortified Madeira wines: relationship to sugar contentPublication . Câmara, José sousa; Marques, José C.; Alves, Maria A.; Ferreira, António C. SilvaThe maturation of Madeira wines usually involves exposure to relatively high temperatures and humidity levels >70%, which affect the aroma and flavor composition and lead to the formation of the typical and characteristic bouquet of these wines. To estimate the levels of sotolon [3-hydroxy-4,5-dimethyl-2(5H)-furanone] and their behavior over time, 86 aged Madeira wines samples (1−25 years old), with different sugar concentrations, respectively, 90 g L-1 for Boal, 110 g L-1 for Malvazia, 25 g L-1 for Sercial, and 65 g L-1 for Verdelho varieties, were analyzed. Isolation was performed by liquid−liquid extraction with dichloromethane followed by chromatographic analysis by GC-MS. The reproducibility of the method was found to be 4.9%. The detection and quantification limits were 1.2 and 2.0 μg L-1, respectively. The levels of sotolon found ranged from not detected to 2000 μg L-1 for wines between 1 and 25 years old. It was observed that during aging, the concentration of sotolon increased with time in a linear fashion (r = 0.917). The highest concentration of sotolon was found in wines with the highest residual sugar contents, considering the same time of storage. The results show that there is a strong correlation between sotolon and sugar derivatives: furfural, 5-methylfurfural, 5-hydroxymethylfurfural, and 5-ethoxymethylfurfural. These compounds are also well correlated with wine aging. These findings indicate that the kinetics of sotolon formation is closely related with residual sugar contents, suggesting that this molecule may come from a component like sugar.