Browsing by Issue Date, starting with "2021-11-23"
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- Targeting aerobic granular sludge microbiome salt adaptationPublication . Paulo, Ana M. S.; Amorim, Catarina L.; Castro, Paula M. L.Saline wastewaters can result from different economical activities, such as food and chemicals industries. The need to overcome water shortage is also producing more saline wastewater, especially in coastal cities where seawater is used for cleaning processes. This is leading to the need for biological wastewater treatment technologies able to tolerate high salt concentrations. Aerobic granular sludge (AGS) has been appointed as the best aerobic treatment process for saline wastewater, mainly due to the high bacterial aggregation and self-protection level that granules offer. Due to the existence of different microbial metabolic layers within the granules, AGS technology is used for removing organic carbon as well as nitrogen and phosphorous from wastewater. In this study, AGS biomass was acclimated to saline wastewater, by performing a stepwise salt addition over a period of 250 days, from 0 to 14 g NaCl L-1. A high bacterial diversity existed while treating wastewater up to 3 g NaCl L-1. However, the salinity increase up to 6 g NaCl L-1 led to a relevant microbial diversity reduction. Salt increase led to the dominance of Proteobacteria, namely of Lysobacter and Rhodocyclus bacterial genera, both associated to carbon-nitrogen removal and EPS production in AGS processes, respectively. Despite this bacterial selection, carbon and nutrients removal processes were kept stable, even when salinity was increased to 14 g NaCl L-1, which was corroborated by the identification of bacteria responsible for such processes (e.g., PAO, AOB and NOB) throughout reactor operation. Hence, the AGS process was able to adapt to salt by preserving the metabolic diversity required for performing different biological removal processes, showing the microbial selection and plasticity occurring in AGS processes, an issue of great relevance for upgrading wastewater treatment.
- Efficient ammonium removal from marine aquaculture wastewater with microalgal-bacterial granular sludge technologyPublication . Alves, Marta; Oliveira, Ana Sofia; Castro, Paula Maria Lima; Amorim, Catarina LeiteWater recirculation in marine aquaculture is fundamental for the protection of water resources and for the sector sustainability as it enables to reduce water usage 1. Microalgal-bacterial granular sludge (MBGS) has the potential to increase the removal efficiency of pollutants from wastewaters benefiting from the diverse metabolism allowing water recirculation. Moreover, MBGS would allow costs reduction both in biomass separation from the treated water given the rapid settling properties and in aeration due to microalgae oxygen production 2.This study aimed to develop MBGS able to treat marine aquaculture effluents. For that, a lab-scale photo sequencing batch reactor was inoculated with activated sludge, previously adapted to salty wastewater, and a microalgae consortium enriched from water collected at a marine aquaculture. Feeding composition was established to simulate marine aquaculture streams. The aggregation of microalgal and bacterial biomass to form granular structures occurred rapidly. Throughout the operation, dark green granules with a dense and compact structure became predominant together with an increase in chlorophyll and carotenoids content in biomass. Ammonia was absent from the reactor effluent, but the nitrite levels were often above the toxicity levels for fish. Nevertheless, the dissolved oxygen concentration in the treated water was high (> 8.63 mg/L). The microalgal-bacterial granules proved to be efficient in producing streams with high dissolved oxygen levels, lowering the needed of water oxygenation before reuse and without ammonium ions. However, for water recirculation, improvement of the nitrite removal is needed to maintain the levels below the fish toxicity levels.
- Probiotic adhesion to skin keratinocytes and underlying mechanismsPublication . Lizardo, M.; Magalhães, R.M.; Tavaria, F.K.
- UVC radiation and ozone as disinfection methods against a viral surrogate of SARS-CoV-2Publication . Neto, Cláudia; Barbosa, Joana; Ferreira, Vânia; Rezende, Lourenço; Oliveira, Mónica; Gomes, Joana; Carvalho, Marta; Ferreira, João; Costa, Ana; Coelho, Nuno; Pintado, Manuela; Teixeira, Paula
- Aerobic granular sludge, a feasible technology for the treatment and recirculation of trout aquaculture water streamsPublication . Couto, Ana T.; Amorim, Catarina L.; Castro, Paula M. L.Aquaculture is one of the fastest growing food production sectors. However, land-based aquaculture faces water scarcity and space restrictions which hamper its development. Aquaculture recirculation systems (RAS) help tackle these problems, although in most systems the recycling of water increases nutrient and organic matter concentrations, which often translates to fish mortality. This work aimed to evaluate the feasibility of an aerobic granular sludge (AGS) system as a novel alternative for the treatment of aquaculture streams, characterized by low nutrient and carbon concentrations. The efficiency for nutrients removal aiming at water recirculation was assessed as well as the AGS microbiome composition dynamics over operation. The AGS system was inoculated with mature granules from a full-scale WWTP and fed with a synthetic medium mimicking a trout farm aquaculture recycling water. High ammonium removal efficiencies of 87-100% and ammonium removal rate of approximately 14.5 mg NH4+-N/(L⋅d) were achieved. The AGS microbiome, mainly composed by members of the Proteobateria phylum, had a core microbiome composed of different functional groups (e.g. denitrifying bacteria, nitrogen fixing bacteria, ammonium oxidizing bacteria, phosphorus accumulating bacteria and extracellular polymeric substance (EPS) producing bacteria). The AGS system was able to produce effluents of high-quality, with ammonium content below the toxic levels for fish, and thus suitable for recirculating in the aquaculture.
- Evaluation of minimum inhibitory concentrations of plants extracts against several bacterial pathogensPublication . Carvalho, Marta; Melo, Adma; Afonso, Tiago; Barbosa, Joana; Ribeiro, Tânia; Tavaria, Freni; Carocho, Márcio; Barros, Lillian; Pintado, Manuela; Teixeira, Paula
- Sugarcane bagasse as source of bioactive lignin: influence of pretreatment on the antioxidant and antibacterial activitiesPublication . Antunes, Filipa; Mota, Inês F.; Burgal, João da Silva; Pintado, Manuela; Costa, Patrícia SantosSugarcane industry generates several by-products of particular interest in the context of a circular economy, due to their potential as a source of value-added ingredients. Bagasse is one of the main by-products, consisting of a fibrous fraction obtained after juice extraction. Sugarcane bagasse is composed of cellulose, hemicellulose, and lignin, with lower amounts of extractives and ash (del Río et al., 2015). Lignin is one of the most abundant renewable resources on earth and recognized as a profitable source of high value compounds. The main functions attributed to lignin in the plant are elasticity and mechanical strength. It is a complex aromatic macromolecule formed by the dehydrogenative polymerization of three phenylpropanoid monomers coniferyl, synapyl, and p-coumaryl alcohols. The antimicrobial activity of lignin is related to plant sources and attributed to the phenolic components, particularly the side-chain structure and its functional groups (Chauhan, 2020). The antioxidant activity of lignin is mainly attributed to the scavenging action of their phenolic structures on oxygen-containing reactive free radicals. For the antioxidant activity of the lignin, free phenolic hydroxyl groups and ortho-methoxy substitution in aromatic rings are essential. The structural characteristics of lignin depend on several factors including the botanical origin, and environmental growth and extraction conditions. The main objective of this work was to study the potential of lignin from sugarcane bagasse as antimicrobial and antioxidant agent and assess the influence of two different pretreatments - deep eutectic solvents and organosolv – on the biological potential.
- O impacto psicológico do doente com delírium nos enfermeiros em contexto de cuidados paliativosPublication . Santos, Rui Carvalho; Coelho, PatríciaIntrodução: O Delírium define-se por uma síndrome caracterizada por perturbações do nível de consciência com défice de atenção e distúrbios da cognição ou perceção que simultaneamente conduz a um processo de disfunção cerebral global com elevado impacto no doente, família e profissionais. De forma a perceber objetivamente a dimensão deste impacto nos profissionais, em particular nos enfermeiros em contexto de cuidados paliativos, pretende-se com este estudo identificar o impacto psicológico do delírium em contexto de cuidados paliativos. Método: revisão sistemática da literatura realizada nos meses de março e abril de 2021 com recurso às bases de dados eletrónicas Pubmed, EBSCO e SCOPUS. Resultados: Foram selecionadas 13 publicações (n=13), entre as quais se incluem estudos qualitativos, quantitativos, etnográficos, artigos de revisão e estado de arte. Entre as publicações identificadas, os investigadores identificam frequentemente a problemática do impacto psicológico nos enfermeiros e a sua associação com o défice de formação dos profissionais. Conclusão: Os achados deste estudo apontam que o evidente impacto psicológico nos enfermeiros, é complexo e caracterizado por dificuldades associadas ao processo de tomada de decisão, dilemas éticos, problemas de imprevisibilidade, sentimentos de desconfiança, isolamento, culpa, raiva, ansiedade e frustração, concomitantemente com o aumento do volume/carga de trabalho que o doente com delírium representa.
- Impact of gastrointestinal digestion on the biological activities of new functional cereal-based granules based on by-products from the food industryPublication . Voss, Glenise Bierhalz; Dias, Ema; Gomes, Ana; Pintado, ManuelaIn recent years, the lifestyle and eating habits of the worldwide population have changed, encouraged by finding healthier and more nutritious food habits. In the last years, consumers have been searching for products with high protein content. Additionally, the consumption of cereals products has been expanding, due to the practicality1. In parallel, food industries generate a high amount of by-products, and although these by-products present a rich nutritional composition, most of these by-products are often undervalued and used as animal feed. In this context, the development of functional granules using by-products from the food industry is an opportunity to contribute to the food products diversification and to consumer health and well-being and to valorize the by-products, promoting the circular economy. Thus, the objective of this work was to evaluate the biological activities impacted by the gastrointestinal digestion (GID) of four new functional cereal-based granules, based on the valorisation of acorn and by-products such as wheat bran, wheat germ and okara. Granules were produced by cold extrusion and their formulation were presented in Figure 1. The GID was performed according to the standardized InfoGest protocol (Brodkorb et al., 2019)2. All granules were characterized regarding their nutritional composition. In addition, total polyphenols, antioxidant activity (ABTS and ORAC assays), proteins profile and oligosaccharides were evaluated in each stage of GID (mouth, stomach, intestinal phase), using FPLC and HPLC methods, respectively. All formulations presented the requirements to attain the claim source or rich in protein (19.6 to 29.6%) and rich in fibre (≥6 g of fibre/100 g). During the GID the release of bioactive compounds was observed, and the in vitro antioxidant activity increased in the intestinal stage. Comparing the formulations, it was possible to observe that the F2 (formulation with acorn and okara) presented the highest ORAC values (11041.73 ± 384.98 µM of Trolox) after GID. Although F1 showed the highest polyphenols concentration (0.86 ± 0.02 mg of Gallic acid/ mL of sample) at the end of GID they all presented similar values. Concerning protein profile, all formulations showed after GID the release of peptides with low MW (< 3 KDa). Relatively to the soluble carbohydrates after GID all granules released oligosaccharides with low MW (< 5 KDa). In conclusion, the results indicated that GID improved the antioxidant activity in the functional granules probably due to the release of polyphenols bond to the fiber, thus suggesting health-protecting effects. Furthermore, these by-products can be valorized as potential ingredients for human consumption, reducing the waste in the food chain and satisfying a market niche based on functional and sustainable products.
- Impact of a pulse-based vegetarian lunch meal on the modulation of gut bacterial populationsPublication . Ferreira, Helena; Barbosa, Joana; Costa, Célia; Vasconcelos, Marta W.; Gomes, Ana; Gil, Ana M.; Pinto, ElisabeteIntroduction: The current global trend to adopt more plant-based diets is expected to increase the intake of pulses in the near future, given their potential as eco-friendly nutrient-rich alternatives to animal-based protein food sources. Still, more comprehensive data, as well as higher quality food intervention trials, are needed to fully understand the health benefits of such dietary shift, namely at the gut microbiota level. In this context, the use of molecular biology research tools, such as quantitative Polymerase Chain Reaction (qPCR) could be useful to monitor the dietary modulation of gut bacterial populations. Objectives: To investigate the modulation of gut bacterial populations after an 8-week pulse-based food intervention using qPCR optimized for 5 bacterial genera.Methods: Non-vegetarian healthy young adults were asked to replace a typical omnivorous lunch meal with a vegetarian pulse-based meal, 5 times per week, for 8 consecutive weeks. Stool samples were collected at weeks 0 (baseline) and 8 and total DNA was extracted using NZY Tissue gDNA isolation Kit (NZYTech, Lisbon, Portugal). A specific sequence region of the gene 16S rRNA was quantified using qPCR specific for the following bacteria: Akkermansia muciciphilamuciniphila, Roseburia spp., BiffidobacteriumBifidobacterium spp., Clostridium leptum subgroup, and Faecalibacterium prausnitzii, was quantified using qPCR. Results: A total of 50 stool samples, from a group of 25 individuals, were collected and analyzed using qPCR. Results revealed an evident interindividual variability after the 8-week pulse-based food intervention, apparently with no clear net tendency on the modulation of the analyzed gut bacterial sub-groups analyzed. Conclusion: An 8-week pulse-based food intervention caused different gut bacteria modulation in each individual, masking any potential generalized effects of the diet. This highlights the need for personalized approaches concerning health and nutrition research fields.