Browsing by Issue Date, starting with "2023-08"
Now showing 1 - 6 of 6
Results Per Page
Sort Options
- Exploring the Multifaceted Potential of a Peptide Fraction Derived from Saccharomyces cerevisiae Metabolism: Antimicrobial, Antioxidant, Antidiabetic, and Anti-Inflammatory PropertiesPublication . Branco, Patricia; Mauricio, Elisabete; Costa, Ana; Ventura, Diogo; Roma-Rodrigues, Catarina; Duarte, Maria Paula; Fernandes, AlexandraABSTRACT: The rising demand for minimally processed, natural, and healthier food products has led to the search for alternative and multifunctional bioactive food components. Therefore, the present study focuses on the functional proprieties of a peptide fraction derived from Saccharomyces cerevisiae metabolism. The antimicrobial activity of the peptide fraction is evaluated against various foodborne pathogens, including Candida albicans, Candida krusei, Escherichia coli, Listeria monocytogenes, and Salmonella sp. The peptide fraction antioxidant properties are assessed using FRAP and DPPH scavenging capacity assays. Furthermore, the peptide fraction's cytotoxicity is evaluated in colorectal carcinoma and normal colon epithelial cells while its potential as an antidiabetic agent is investigated through alpha-amylase and ff-glucosidase inhibitory assays. The results demonstrate that the 2-10 kDa peptide fraction exhibits antimicrobial effects against all tested microorganisms, except C. krusei. The minimal inhibitory concentration for E. coli, L. monocytogenes, and Salmonella sp. remains consistently low, at 0.25 mg/mL, while C. albicans requires a higher concentration of 1.0 mg/mL. Furthermore, the peptide fraction displays antioxidant activity, as evidenced by DPPH radical scavenging activity of 81.03%, and FRAP values of 1042.50 +/- 32.5 mu M TE/mL at 1.0 mg/mL. The peptide fraction exhibits no cytotoxicity in both tumor and non-tumoral human cells at a concentration up to 0.3 mg/mL. Moreover, the peptide fraction presents anti-inflammatory activity, significantly reducing the expression of the TNF ff gene by more than 29.7% in non-stimulated colon cells and by 50% in lipopolysaccharide-stimulated colon cells. It also inhibits the activity of the carbohydrate digestive enzymes alpha-amylase (IC50 of 199.3 +/- 0.9 mu g/mL) and alpha-glucosidase (IC20 of 270.6 +/- 6.0 mu g/mL). Overall, the findings showed that the peptide fraction exhibits antibacterial, antioxidant, anti-inflammatory, and antidiabetic activity. This study represents a step forward in the evaluation of the functional biological properties of S. cerevisiae bioactive peptides.
- Braquiópodes do Museu da Lourinhã (Portugal)Publication . Madeira Mateus, Simão Gustavo; Veloso, RodrigoRESUMO: O acervo fóssil do Museu da Lourinhã destaca-se pelos ossos e ovos de vertebrados terrestres mesozoicos, nomeadamente do Jurássico Superior, a série predominante dos terrenos da região. Quase todos os fósseis de braquiópodes deste museu provêm de outros municípios e têm importância didática enquanto representativos de um grupo de invertebrados marinhos, apelativo para fins expositivos e educativos. Este trabalho, realizado no âmbito da organização e valorização da coleção paleontológica do Museu da Lourinhã, dá a conhecer a coleção de braquiópodes desta instituição, constituída por 40 registos pertencentes a 18 géneros. Estes são maioritariamente portugueses, mas há alguns exemplares estrangeiros, oferecidos por paleontólogos colaboradores, a maioria do Silúrico de Gotlândia, Suécia.
- How much extreme weather events have affected European power generation in the past 30 years?Publication . Brás, Teresa; Simoes, Sofia; Amorim, FilipaABSTRACT: Power generation impacts due to extreme weather events (EWE), as floods, storms, cold waves, droughts, and heatwaves, are not well understood across larger spatial scales, especially in view of climate change. These events can se-verely affect our energy supply by interrupting the energy generation or its transmission, by interfering with fuel production and distribution, or by causing fuel and electricity shortages, potentially leading to price spikes.
- Oligosaccharides production by enzymatic hydrolysis of banana pseudostem pulpPublication . Díaz, Sara; Ortega, Zaida; Benítez Vega, Antonio Nizardo; Marrero, María D.; Carvalheiro, Florbela; Duarte, Luís C.; Matsakas, Leonidas; Krikigianni, Eleni; Rova, Ulrika; Christakopolous, Paul; Fernandes, M. C.ABSTRACT: Banana production generates significant amounts of agricultural wastes, being fiber extraction one of the most relevant alternatives for their valorization. This process produces banana's pseudostem pulp (BPP) as a byproduct, which shows an interesting composition for the biorefinery's biochemical platform, with high polysaccharides (68%) and low lignin contents. This work deals with the enzymatic hydrolysis (EH) of raw and hydrothermally pre-treated BPP, focusing on the production of oligosaccharides (OS). Raw BPP hydrolysis with cellulase at different dosages rendered only 3.2% OS yields (OSY). Pectinase addition has not affected EH performance. On the other hand, EH of hydrothermally pre-treated BPP at 150 degrees C and 170 degrees C (P150 and P170) allowed to increase OSY up to 28% (P150, 1 FPU of cellulase/g dry biomass, 12 h), being 72% of the solubilized sugars in the form of cello-oligosaccharides. This last condition was subjected to a multi-stage EH strategy without improvements in OSY. An endo-glucanase was also tested, but obtained OSY were lower than cellulase results. Finally, obtained OS demonstrated to stimulate the growth of two Lactobacilli strains. The results show that BPP pre-treated under mild operational conditions is a good candidate for cello-oligosaccharides production by EH using 1 FPU/g DB of cellulase with a simple strategy.
- A new impetus for biodesulfurization: bypassing sulfate inhibition in biocatalyst productionPublication . Silva, Tiago; Paixão, Susana M.; Alves, LuísABSTRACT: Biodesulfurization is a biotechnological process that employs microorganisms as biocatalysts to remove sulfur from fuels usually at mesophilic conditions, targeting recalcitrant organosulfur compounds without affecting their hydrocarbon structure. One of the bottlenecks hindering its large-scale application is the inhibition of biodesulfurization activity by easily metabolized sulfur compounds, such as sulfates, even at residual concentrations. This increases production costs by requiring high-purity sulfur-free nutrients or complex induction steps to prevent/revert inhibition. The objective of this work was to bypass this limitation and demonstrate that it is possible to produce biocatalysts with biodesulfurization activity using sulfate as the only sulfur source, without employing inducers or genetic manipulation, simply by adjusting the sulfur : carbon ratio in continuous culture. With this goal, the bacterium Gordonia alkanivorans strain 1B was cultivated in a chemostat with a medium containing 10 g L-1 of fructose as the carbon source and different sulfate concentrations (12-50 mg per L SO42-) using Na2SO4. Then the bacteria were employed as biocatalysts in biodesulfurization assays with a recalcitrant organosulfur compound (dibenzothiophene). Under these conditions it was observed that 2.2 mg(sulfate) g(fructose)(-1) ensured a biodesulfurization activity of 6.1 & mu;mol g(DCW)(-1) h(-1), 15% greater than previously reported for this strain with an inducer, without limiting biocatalyst production. This novel procedure was further applied to another biocatalyst, Rhodococcus erythropolis strain D1, validating its wide applicability to other desulfurizing microorganisms. Overall, these results indicate a previously unknown regulation mechanism dependent on relative sulfur concentration, which influences cellular responses and regulates biodesulfurization activity, allowing the use of easily metabolized sulfur sources to produce cost-effective biocatalysts for biodesulfurization.
- Starty explains START: Issue 2Publication . Neves, Filipe; Mascarenhas, JoãoABSTRACT: Learn more about START with the second multilingual issue of Starty, our friendly robot that helps us explain the project scope! In this issue, Starty addresses topics such as the link between raw materials and the energy transition and also presents the countries where the tetrahedrite mineral is collected for its incorporation in the production process of thermoelectric materials within the scope of the START activities.