Browsing by Author "Ferreira, Carlos"
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- An eco-friendly and up-scalable approach to extract canthaxanthin from yeast cellsPublication . Pereira, Ana M.; Durão, Joana; Pereira, Joana Odila; Ferreira, Carlos; Faustino, Margarida; Oliveira, Ana Sofia; Pereira, Carla F.; Pintado, Manuela E.; Carvalho, Ana P.Canthaxanthin is a naturally occurring ketocarotenoid pigment present in plants, algae, bacteria and some fungi. In addition to its coloring role, canthaxanthin has an excellent antioxidant activity, thus having additional market demands in the feed, food, cosmetic and pharmaceutical industries. Canthaxanthin can be directly isolated from its natural source or produced by chemical synthesis, but these strategies either result in low yields, or use hazardous solvents, respectively. Therefore, the biosynthesis of canthaxanthin using microbial cell factories is becoming an advantageous alternative. Furthermore, microbial synthesis represents an economic and sustainable approach as it enables the use of agriculture and industrial wastes as substrates. In this work, the extraction, recovery and purification of canthaxanthin from modified yeasts using food grade solvents and up-scalable methodologies was studied. The resulting canthaxanthin-enriched extract was characterized (UV-Vis, PXRD and SEM) and quantified (HPLC), resulting in a canthaxanthin purity of 43.7 % (w/w).
- Comparative analysis of mannans extraction processes from spent yeast saccharomyces cerevisiaePublication . Faustino, Margarida; Durão, Joana; Pereira, Carla F.; Oliveira, Ana Sofia; Pereira, Joana Odila; Pereira, Ana M.; Ferreira, Carlos; Pintado, Manuela E.; Carvalho, Ana P.Mannans are outstanding polysaccharides that have gained exponential interest over the years. These polysaccharides may be extracted from the cell wall of Saccharomyces cerevisiae, and recovered from the brewing or synthetic biology industries, among others. In this work, several extraction processes—physical, chemical and enzymatic—were studied, all aiming to obtain mannans from spent yeast S. cerevisiae. Their performance was evaluated in terms of yield, mannose content and cost. The resultant extracts were characterized in terms of their structure (FT-IR, PXRD and SEM), physicochemical properties (color, molecular weight distribution, sugars, protein, ash and water content) and thermal stability (DSC). The biological properties were assessed through the screening of prebiotic activity in Lactobacillus plantarum and Bifidobacterium animalis. The highest yield (58.82%) was achieved by using an alkaline thermal process, though the correspondent mannose content was low. The extract obtained by autolysis followed by a hydrothermal step resulted in the highest mannose content (59.19%). On the other hand, the extract obtained through the enzymatic hydrolysis displayed the highest prebiotic activity. This comparative study is expected to lay the scientific foundation for the obtention of well-characterized mannans from yeast, which will pave the way for their application in various fields.
- Effect of drying technology in Saccharomyces cerevisiae mannans: structural, physicochemical, and functional propertiesPublication . Faustino, Margarida; Pereira, Carla F.; Durão, Joana; Oliveira, Ana Sofia; Pereira, Joana Odila; Ferreira, Carlos; Pintado, Manuela E.; Carvalho, Ana P.Mannans are polysaccharides whose physicochemical and biological properties render them commercialization in several products. Since these properties are strongly dependent on production conditions, the present study aims to assess the impact of different drying technologies – freeze (FDM) and spray drying (SDM) – on the structural, physicochemical, and biological properties of mannans from Saccharomyces cerevisiae. Structural analysis was assessed by FT-IR, PXRD and SEM, whereas physicochemical properties were evaluated based on sugars, protein, ash and water contents, solubility, and molecular weight distribution. Thermal behaviour was analysed by DSC, and antioxidant activity by DPPH and ABTS assays. The parameters which revealed major differences, in terms of structural and physicochemical properties regarded morphology (SEM), physical appearance (colour), moisture (3.6 ± 0.1 % and 11.9 ± 0.6% for FDM and SDM, respectively) and solubility (1 mg/mL for FDM and 25 mg/mL for SDM). Nevertheless, these differences were not translated into the antioxidant capacity.
- Peptide extract from spent yeast improves resistance of Saccharomyces cerevisiae to oxidative stressPublication . Lopes, Ana; Azevedo-Silva, João; Carsanba, Erdem; Pintado, Manuela; Oliveira, Ana Sofia; Ferreira, Carlos; Pereira, Joana Odila; Carvalho, Ana P.; Oliveira, CarlaYeast cells face various stress factors during industrial fermentations, since they are exposed to harsh environmental conditions, which may impair biomolecules productivity and yield. In this work, the use of an antioxidant peptide extract obtained from industrial spent yeast was explored as supplement for Saccharomyces cerevisiae fermentation to prevent a common bottleneck: oxidative stress. For that, a recombinant yeast strain, producer of β-farnesene, was firstly incubated with 0.5 and 0.7 g/L peptide extract, in the presence and absence of hydrogen peroxide (an oxidative stress inducer), for 1–5 h, and then assayed for intracellular reactive oxygen species, and growth ability in agar spot assays. Results showed that under 2 mM H2O2, the peptide extract could improve cells growth and reduce reactive oxygen species production. Therefore, this antioxidant effect was further evaluated in shake-flasks and 2-L bioreactor batch fermentations. Peptide extract (0.7 g/L) was able to increase yeast resistance to the oxidative stress promoted by 2 mM H2O2, by reducing reactive oxygen species levels between 1.2- and 1.7-fold in bioreactor and between 1.2- and 3-fold in shake-flask fermentations. Moreover, improvements on yeast cell density of up to 1.5-fold and 2-fold, and on biomolecule concentration of up to 1.6-fold and 2.8-fold, in bioreactor and shake-flasks, respectively, were obtained. Thus, culture medium supplementation with antioxidant peptide extracted from industrial spent yeast is a promising strategy to improve fermentation performance while valuing biomass waste. This valorization can promote a sustainable and eco-friendly solution for the biotechnology industry by the implementation of a circular economy model.
- Peptide-rich extracts from spent yeast as potential microbiota modulatorsPublication . Oliveira, Ana Sofia; Carvalho, Nelson Mota de; Ferreira, Carlos; Pereira, Joana Odila; Pintado, Manuela; Madureira, Ana Raquel; Carvalho, Ana P.
- Spent brewer's yeast (saccharomyces cerevisiae) as a potential source of bioactive peptides: an overviewPublication . Oliveira, Ana Sofia; Ferreira, Carlos; Pereira, Joana Odila; Pintado, Manuela E.; Carvalho, Ana P.Bioactive peptides become popular in several economic sectors over the years as they have demonstrated important biological benefits in digestive, immune, cardiovascular, and nervous human systems. Although many commercial peptides are chemically synthesized, they can also be obtained from natural protein sources such as spent brewer's yeast (Saccharomyces cerevisiae). The recovery of this fermentation by-product for production of functional ingredients is an important step in the increasingly demand to implement and promote a circular economy-based industry. Bioactive peptides can be found in protein-rich extracts produced from S. cerevisiae, and several studies have described their positive impact of human body. In this line, the present review highlights and discuss the reported biological properties of S. cerevisiae bioactive peptides in terms of antihypertensive, antioxidant and antimicrobial effects, although other bioactivities are also described. Concerning the growing interest in yeast protein-rich products by agri-food and cosmetic sectors, some of the products currently on the market are also pointed out and their potential source is discussed.
- Spent yeast valorization for food applications: effect of different extraction methodologiesPublication . Oliveira, Ana Sofia; Pereira, Joana Odila; Ferreira, Carlos; Faustino, Margarida; Durão, Joana; Pereira, Ana Margarida; Oliveira, Carla Maria; Pintado, Manuela E.; Carvalho, Ana P.Over the years, synthetic biology has been growing with the use of engineered yeast strains for the production of sustainable ingredients to meet global healthcare, agriculture, manufacturing and environmental challenges. However, as seen from the brewing industry perspective, these processes generate a substantial amount of spent yeast that contains high nutritional value related to its high protein content, showing its potential to be used as an alternative protein source. Taking into account the rising demand for protein because of the growth in the global population, the present study aims to produce peptide-rich extracts by different potentially scalable and sustainable methodologies in a circular economy approach for the food and nutraceutical industries. The results demonstrated that extraction from genetically modified strains allowed the production of extracts with an excellent nutritional profile and low molecular weight peptides. Furthermore, autolysis was shown to be a potential sustainable approach for this production, though other green metrics need to be explored in order to establish this process at an industrial level.
- Spent yeast waste streams as a sustainable source of bioactive peptides for skin applicationsPublication . Costa, Eduardo M.; Oliveira, Ana Sofia; Silva, Sara; Ribeiro, Alessandra B.; Pereira, Carla F.; Ferreira, Carlos; Casanova, Francisca; Pereira, Joana O.; Freixo, Ricardo; Pintado, Manuela E.; Carvalho, Ana Paula; Ramos, Óscar L.Spent yeast waste streams are a byproduct obtained from fermentation process and have been shown to be a rich secondary source of bioactive compounds such as phenolic compounds and peptides. The latter are of particular interest for skin care and cosmetics as they have been shown to be safe and hypoallergenic while simultaneously being able to exert various effects upon the epidermis modulating immune response and targeting skin metabolites, such as collagen production. As the potential of spent yeast’s peptides has been mainly explored for food-related applications, this work sought to understand if peptide fractions previously extracted from fermentation engineered spent yeast (Saccharomyces cerevisiae) waste streams possess biological potential for skin-related applications. To that end, cytotoxic effects on HaCat and HDFa cells and whether they were capable of exerting a positive effect upon the production of skin metabolites relevant for skin health, such as collagen, hyaluronic acid, fibronectin and elastin, were evaluated. The results showed that the peptide fractions assayed were not cytotoxic up to the highest concentration tested (500 µg/mL) for both cell lines tested. Furthermore, all peptide fractions showed a capacity to modulate the various target metabolites production with an overall positive effect being observed for the four fractions over the six selected targets (pro-collagen IαI, hyaluronic acid, fibronectin, cytokeratin-14, elastin, and aquaporin-9). Concerning the evaluated fractions, the overall best performance (Gpep > 1 kDa) was of an average promotion of 41.25% over the six metabolites and two cell lines assessed at a concentration of 100 µg/mL. These results showed that the peptide fractions assayed in this work have potential for future applications in skin-related products at relatively low concentrations, thus providing an alternative solution for one of the fermentation industry’s waste streams and creating a novel and highly valuable bioactive ingredient with encompassing activity to be applied in future skin care formulations.
- A step for the valorization of spent yeast through production of iron–peptide complexes — a process optimization studyPublication . Ferreira, Carlos; Pereira, Carla F.; Oliveira, Ana Sofia; Faustino, Margarida; Pereira, Ana M.; Durão, Joana; Pereira, Joana Odila; Pintado, Manuela E.; Carvalho, Ana P.Given the importance of iron in human nutrition and the significance of waste and by-product valorisation in a circular economy environment, we investigated the effects of protein and iron concentration on the production yield of iron–peptide complexes from spent Saccharomyces cerevisiae. For this purpose, different amounts of protein and iron were used in the complexation process. The results have shown that higher concentrations, although permitting a faster and larger scale process, provide a significantly lower complexation yield, which deems the process less feasible. This is corroborated by fluorescence analysis, which shows a lower degree of complexation with higher protein concentration. In addition, varying the concentration of iron does not change the quality of formed complexes, as evidenced by Fourier transform infrared spectroscopy (FT-IR) analysis. The morphology of all samples was also evaluated using scanning electron microscopy (SEM). Therefore, further studies are needed to optimize the process and to evaluate the best conditions for an economically sound valorization process for iron–peptide complexes. Nonetheless, current results in the development of a new process for the valorisation of spent yeast, in the form of iron-peptide complexes, look promising.
- Valorisation of protein-rich extracts from spent brewer’s yeast (Saccharomyces cerevisiae): an overviewPublication . Oliveira, Ana Sofia; Ferreira, Carlos; Pereira, Joana Odila; Pintado, Manuela E.; Carvalho, Ana P.As one of the main brewing by-products, Saccharomyces cerevisiae extracts (from spent yeast) have been commercialized as food supplement for years. Among their several claims, the application as protein source is highlighted. In fact, their high protein content (about 45–60%) including essential amino acids with high biological value, safety and low cost are primarily responsible for their spreading in agri-food sector. Meanwhile, cosmetic and health sectors have been working on yeast bioactive peptides because of their antihypertensive, antioxidant and antimicrobial properties, among others. Several studies related to valorisation of S. cerevisiae are currently ongoing, aiming to create novel products and optimize production processes. The present review aims to provide an overview from production of protein-rich extracts from S. cerevisiae to their chemical characterisation, detailing protein extraction, isolation and purification processes, as well as characterisation methods for the final extracts.