Encapsulation of combi-cleas of glycosidases in alginate beads and polyvinyl alcohol for wine aroma enhancement

The aromatic expression of wines can be enhanced by the addition of specific glycosidases, although their poor stability remains a limitation. Coimmobilization of glycosidases as cross-linked enzyme aggregates (combi-CLEAs) offers a simple solution yielding highly stable biocatalysts. Nevertheless, the small particle size of combi-CLEAs hinders their recovery, preventing their industrial application. Encapsulation of combi-CLEAs of glycosidases in alginate beads and in polyvinyl alcohol is proposed as a solution. Combi-CLEAS of β-D-glucosidase and α-L-arabinofuranosidase were prepared and encapsulated. The effects of combi-CLEA loading and particle size on the expressed specific activity (IU/g) of the biocatalysts were evaluated. Best results were obtained with 2.6 mm diameter polyvinyl alcohol particles at a loading of 60 mg/g, exhibiting activities of 1.9 and 1.0 IU/g for β-D-glucosidase and α-L-arabinofuranosidase, respectively. Afterwards, the stability of the biocatalysts was tested in white wine. All the encapsulated biocatalysts retained full activity after 140 incubation days, outperforming both free enzymes and nonencapsulated combi-CLEAs. Nevertheless, the alginate-encapsulated biocatalysts showed a brittle consistency, making recovery unfeasible. Conversely, the polyvinyl-encapsulated biocatalyst remained intact throughout the assay. The encapsulation of combi-CLEAs in polyvinyl alcohol proved to be a simple methodology that allows their recovery and reuse to harness their full catalytic potential

Uncovering the Mechanism of Aggregation of Human Transthyretin.

The tetrameric thyroxine transport protein transthyretin (TTR) forms amyloid fibrils upon dissociation and monomer unfolding. The aggregation of transthyretin has been reported as the cause of the life-threatening transthyretin amyloidosis. The standard treatment of familial cases of TTR amyloidosis has been liver transplantation. Although aggregation-preventing strategies involving ligands are known, understanding the mechanism of TTR aggregation can lead to additional inhibition approaches. Several models of TTR amyloid fibrils have been proposed, but the segments that drive aggregation of the protein have remained unknown. Here we identify β-strands F and H as necessary for TTR aggregation. Based on the crystal structures of these segments, we designed two non-natural peptide inhibitors that block aggregation. This work provides the first characterization of peptide inhibitors for TTR aggregation, establishing a novel therapeutic strategy

Mudanças climáticas no eucalipto: modelos de desenvolvimento e zoneamento de aptidão climática

The climate projections indicate an increase in air temperature and changes in rainfall patterns throughout the Brazilian territory, which may impact the cultivation of forest species. Thus, it becomes important to conduct studies that analyze the potential impacts of climate projections, especially for those economically important, such as eucalyptus. Given these aspects, the aims of this master's thesis were: a) to calibrate and evaluate the development simulation models Phyllochron (PHYL) and Wang and Engel (WE) for the present climate, as well as to identify the possible impacts of projected increases in air temperature on the duration of the seedling phase (SDP) of two species of eucalyptus, considering two scenarios of radioactive forncing (RCP 4.5 e RCP 8.5) and; b) to evaluate the impacts of climate projections in agroclimatic zoning for the main species of eucalyptus cultivated in Brazil, considering the water and thermal limitations of the species for two scenarios of radiative forcing. The two models (PHYL and WE) were able to predict the dynamics of development in two species, with better performance of the WE model. The projected increase in air temperature throughout the 21st century may modify the development rates and SDP of the two species of eucalyptus cultivated in Itajubá, as well as in subtropical climate regions, reducing the development rate, and increasing the permanence of seedlings in forest nurseries. There will be no considerable changes in the adequate areas for eucalyptus cultivation in Brazilian territory for the near future (2021-2050). However, at the end of the 21st century (2071-2100) there may be a reduction from 3% (RCP 4.5) to 7% (RCP 8.5) of totally or adequate areas of eucalyptus cultivation comparead to present climate (1980 – 2005), and the appearance of restricted areas, up to 47%, due to the increase of water deficit in eucalyptus cultivation in the far future.Agência 1As projeções climáticas indicam aumento da temperatura do ar e alterações nos padrões de precipitação em todo o território brasileiro, os quais poderão impactar o cultivo de espécies florestais. Desta forma, torna-se importante a realização de estudos que analisem os potenciais impactos das projeções climáticas, especialmente para aquelas economicamente importantes, como o eucalipto. Diante destes aspectos, os objetivos dessa dissertação de mestrado foram: a) calibrar e avaliar os modelos de simulação do desenvolvimento filocrono (FIL) e Wang e Engel (WE) para o clima presente, assim como identificar os possíveis impactos dos aumentos projetados de temperatura do ar na duração da fase de muda (DFM) de duas espécies de eucalipto, considerando dois cenários de fornçantes radiativas (RCP 4.5 e RCP 8.5) e; b) avaliar os impactos das projeções climáticas nas áreas de aptidão climática para as principais espécies de eucalipto cultivadas no Brasil, considerando as limitações hídricas e térmicas das espécies e para dois cenários de forçantes radiativas (RCP 4.5 e RCP 8.5). Os dois modelos (FIL e WE) foram capazes de predizer a dinâmica do desenvolvimento para as duas espécies, com desempenho superior do modelo WE. Os aumentos projetados da temperatura do ar ao longo do século XXI poderão modificar as taxas de desenvolvimento e a DFM das duas espécies de eucalipto cultivadas em Itajubá, assim como em regiões de clima subtropical, reduzindo a taxa de desenvolvimento e aumentando a permanência das mudas nos viveiros florestais. Não haverá alterações consideráveis nas áreas de aptidão ao cultivo do eucalipto no território brasileiro para o futuro próximo (2021-2050). No entanto, no final do século XX1 (2071-2100) poderá ocorrer redução de 3% (RCP 4.5) a 7% (RCP 8.5) das áreas totalmente adequadas ou adequadas ao cultivo de eucalipto comparado ao clima presente (1980 – 2005), e o surgimento de áreas restritas, até 47% do território brasileiro, nas quais há inadequação hídrica ao cultivo do eucalipto em longo prazo

Enzymatic Synthesis of Ascorbyl Palmitate in a Rotating Bed Reactor

Ascorbyl palmitate, an ascorbic acid ester, is an important amphipathic antioxidant that has several applications in foods, pharmaceuticals, and cosmetics. The enzymatic synthesis of ascorbyl palmitate is very attractive, but few efforts have been made to address its process scale-up and implementation. This study aimed at evaluating the enzymatic synthesis of ascorbyl palmitate in a rotating basket reactor operated in sequential batches. Different commercial immobilized lipases were tested, and the most suitable reaction conditions were established. Among those lipases studied were Amano Lipase PS, Lipozyme ® TL IM, Lipozyme ® Novo 40086, Lipozyme ® RM IM and Lipozyme ® 435. Initially, the enzymes were screened based on previously defined synthesis conditions, showing clear differences in behavior. Lipozyme ® 435 proved to be the best catalyst, reaching the highest values of initial reaction rate and yield. Therefore, it was selected for the following studies. Among the solvents assayed, 2-methyl-2-butanol and acetone showed the highest yields, but the operational stability of the catalyst was better in 2-methyl-2-butanol. The tests in a basket reactor showed great potential for large-scale application. Yields remained over 80% after four sequential batches, and the basket allowed for easy catalyst recycling. The results obtained in basket reactor are certainly a contribution to the enzymatic synthesis of ascorbyl palmitate as a competitive alternative to chemical synthesis. This may inspire future cost-effectiveness studies of the process to assess its potential as a viable alternative to be implemented

Development of a hybrid bioinorganic nanobiocatalyst : Remarkable impact of the immobilization conditions on activity and stability of β-galactosidase

Hybrid bioinorganic biocatalysts have received much attention due to their simple syn-thesis, high efficiency, and structural features that favor enzyme activity and stability. The present work introduces a biomineralization strategy for the formation of hybrid nanocrystals from β-ga-lactosidase. The effects of the immobilization conditions were studied, identifying the important effect of metal ions and pH on the immobilization yield and the recovered activity. For a deeper understanding of the biomineralization process, an in silico study was carried out to identify the ion binding sites at the different conditions. The selected β-galactosidase nanocrystals showed high specific activity (35,000 IU/g biocatalyst) and remarkable thermal stability with a half-life 11 times higher than the soluble enzyme. The nanobiocatalyst was successfully tested for the synthesis of galacto-oligosaccharides, achieving an outstanding performance, showing no signs of diffusional limitations. Thus, a new, simple, biocompatible and inexpensive nanobiocatalyst was produced with high enzyme recovery (82%), exhibiting high specific activity and high stability, with promis-ing industrial applications

Early fault diagnosis strategy for WT main bearings based on SCADA data and one-class SVM

To reduce the levelized cost of wind energy, through the reduction in operation and maintenance costs, it is imperative that the wind turbine downtime is reduced through maintenance strategies based on condition monitoring. The standard approach toward this challenge is based on vibration monitoring, which requires the installation of specific tailored sensors that incur associated added costs. On the other hand, the life expectancy of wind parks built during the 1990s wind power boom is dwindling, and data-driven maintenance strategies issued from already accessible supervisory control and data acquisition (SCADA) data is an auspicious competitive solution because no additional sensors are required. Note that it is a major issue to provide fault diagnosis approaches built only on SCADA data, as these data were not established with the objective of being used for condition monitoring but rather for control capacities. The present study posits an early fault diagnosis strategy based exclusively on SCADA data and supports it with results on a real wind park with 18 wind turbines. The contributed methodology is an anomaly detection model based on a one-class support vector machine classifier; that is, it is a semi-supervised approach that trains a decision function that categorizes fresh data as similar or dissimilar to the training set. Therefore, only healthy (normal operation) data is required to train the model, which greatly expands the possibility of employing this methodology (because there is no need for faulty data from the past, and only normal operation SCADA data is needed). The results obtained from the real wind park show that this is a promising strategy.Peer ReviewedObjectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant::7.2 - Per a 2030, augmentar substancialment el percentatge d’energia renovable en el con­junt de fonts d’energiaObjectius de Desenvolupament Sostenible::7 - Energia Assequible i No ContaminantPostprint (published version

ZnO Materials as Effective Anodes for the Photoelectrochemical Regeneration of Enzymatically Active NAD+

This work reports the study of ZnO-based anodes for the photoelectrochemical regeneration of the oxidized form of nicotinamide adenine dinucleotide (NAD+). The latter is the most important coenzyme for dehydrogenases. However, the high costs of NAD+ limit the use of such enzymes at the industrial level. The influence of the ZnO morphologies (flower-like, porous film, and nanowires), showing different surface area and crystallinity, was studied. The detection of diluted solutions (0.1 mM) of the reduced form of the coenzyme (NADH) was accomplished by the flower-like and the porous films, whereas concentrations greater than 20 mM were needed for the detection of NADH with nanowire-shaped ZnO-based electrodes. The photocatalytic activity of ZnO was reduced at increasing concentrations of NAD+ because part of the ultraviolet irradiation was absorbed by the coenzyme, reducing the photons available for the ZnO material. The higher electrochemical surface area of the flower-like film makes it suitable for the regeneration reaction. The illumination of the electrodes led to a significant increase on the NAD+ regeneration with respect to both the electrochemical oxidation in dark and the only photochemical reaction. The tests with formate dehydrogenase demonstrated that 94% of the regenerated NAD+ was enzymatically active

Porphyromonas gulae y los anticuerpos PPAD no están relacionados con la citrulinación en la artritis reumatoide

Introducción: Porphyromonas gulae posee la enzima PPAD, al igual que P. gingivalis, responsable de la citrulinación relacionada con la fisiopatología de la artritis reumatoide y la periodontitis; esto implica la presencia de dos especies de bacterias productoras de PPAD en la boca, así como la presencia de proteínas citrulinadas. No existen informes ni estudios previos que investiguen una asociación entre la PPAD de P. gulae en la artritis reumatoide (AR). Objetivo: Evaluar la presencia de P. gulae y anticuerpos antipéptido citrulinado de P. gulae PAD en pacientes con AR y su posible relación con marcadores de actividad clínica. Sujetos y métodos: Se incluyeron un total de 95 pacientes con AR y 95 controles. Se midieron la velocidad de eritrosedimentación (VSG), la proteína C reactiva, los anticuerpos antiproteínas citrulinadas (ACPA) y el factor reumatoide (FR). Índice de actividad-28 (DAS28) y SCDAI. Se estableció el diagnóstico periodontal. Presencia de P. gulae y P. gingivalis. Se utilizó un ELISA para determinar anticuerpos contra los péptidos citrulinados del PAD de P. gulae. Resultados: Se observó una frecuencia de P. gulae del 15,8% en el grupo AR y del 9,5% en el grupo control. Se encontraron mayores niveles de ACPA en los pacientes P. gulae-positivos del grupo AR, sin encontrar diferencias significativas, pero si en los pacientes positivos para P. gingivalis con significación estadística (p = 0,0001). La frecuencia de anticuerpos anti-VDK-cit y anti-LPQ-cit9 frente a PPAD de P. gulae fue mayor en el grupo AR que en el grupo control sin diferencia significativa. No se halló ninguna relación con las variables clínicas a pesar de la presencia de anticuerpos contra el péptido P. gulae y anticuerpos antipéptido citrulinado de la PPAD de P. gulae en pacientes con AR Conclusiones: No fue posible establecer una conexión con las variables clínicas en AR y P. gulae; como resultado, la presencia de P. gingivalis sigue contribuyendo significativamente al aumento de anticuerpos contra proteínas/péptidos citrulinados de fuentes exógenas de citrulinación en AR y periodontitisIntroduction: Porphyromonas gulae have the enzyme PPAD, as P. gingivalis, which is responsible for citrullination related to the pathophysiology of rheumatoid arthritis and periodontitis; this implies the presence of two species of PPAD-producing bacteria in the mouth as well as the presence of citrullinated proteins. There are no previous reports or studies investigating an association between P. gulae PPAD in rheumatoid arthritis (RA). Objective: To assess the presence of P. gulae and anti-citrullinated peptide antibodies of P. gulae PAD in patients with RA and their possible relationship with clinical activity markers. Subjects and methods: A total of 95 patients with RA and 95 controls were included. Erythrocyte sedimentation rate (ESR), C-reactive protein, anti-citrullinated protein antibodies (ACPAs) and rheumatoid factor (RF) were measured. Activity index-28 (DAS28) and SCDAI. The periodontal diagnosis was established. Presence of P. gulae and P. gingivalis. An ELISA was used to determine antibodies against citrullinated peptides of P. gulae PAD. Results: A P. gulae frequency of 15.8% was observed in the RA group and 9.5% in the control group. Higher levels of ACPA were found in the P. gulae-positive patients of the RA group, finding no significant difference, but if in patients positive for P. gingivalis with statistical significance (p = 0.0001). The frequency of anti-VDK-cit and anti-LPQ-cit9 antibodies to PPAD of P. gulae was higher in the RA group than in the control group without significant difference. No relationship was found with the clinical variables despite the presence of P. gulae and anti-citrullinated peptide antibodies of P. gulae PPAD in patients with RA Conclusions: It was not possible to establish a connection with clinical variables in RA and P. gulae; as a result, the presence of P. gingivalis continues to contribute significantly to the increase in antibodies against citrullinated proteins/peptides from exogenous sources of citrullination in RA and periodontitis

Effect of inactivation and reactivation conditions on activity recovery of enzyme catalysts

Enzymes are labile catalysts with reduced half-life time that can be however improved by immobilization and, furthermore, already inactivated catalyst can be recovered totally or partially, therefore allowing the large scale application of enzymes as process catalysts. In recent years a few studies about reactivation of enzyme catalysts have been published as a strategy to prolong the catalyst lifetime. Reported results are very good, making this strategy an interesting tool to be applied to industrial process. These studies have been focused in the evaluation of different variables that may have a positive impact both in the rate and level of activity recovery, being then critical variables for conducting the reactivation process at productive scale. The present work summarizes the studies done about reactivation strategies considering different variables: type of immobilization, enzyme-support interaction, level of catalyst inactivation prior to reactivation, temperature and presence of modulators