Publications by authors named "Everaldo S Dos Santos"

The role of oxidative stress in health and homeostasis has generated interest in the scientific community due to its association with cardiovascular and neurodegenerative diseases, cancer, and other diseases. Therefore, extensive research seeks to identify new exogenous antioxidant compounds for supplementation. Polysaccharides are recognized for their antioxidant properties.

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The objective of this study was to investigate the dual modification of red rice starch using pulsed electric field (PEF) and α-amylase, focusing on morpho-structural, thermal, and viscoamylographic properties. Native starch (Control) underwent various treatments: PEF at 30 kV cm (PEF30), α-amylase at 9.0 U mg (AA0), and a combination of both (PEF30 + α and α + PEF30).

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This review emphasizes the crucial role of enzyme immobilization technology in advancing the production of two main biofuels, ethanol and biodiesel, with a specific focus on the Cross-linked Enzyme Aggregates (CLEAs) strategy. This method of immobilization has gained attention due to its simplicity and affordability, as it does not initially require a solid support. CLEAs synthesis protocol includes two steps: enzyme precipitation and cross-linking of aggregates using bifunctional agents.

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This paper establishes an efficient protocol for the immobilization of Thermomyces lanuginosus lipase (TLL) on a hydrophobic resin, Streamline phenyl. The biocatalyst produced by TLL immobilization on Streamline phenyl resin was named iTLL. In addition, strategies to improve stability and reusability of iTLL were performed using polyethylenimine (PEI) or/and glutaraldehyde (GA), producing iTLL-GA, iTLL-PEI, iTLL-PEI-GA biocatalysts.

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The sustainable development of the drylands, i.e., regions with limited availability of water, depends on the exploitation of the few biomass types that can thrive in such conditions, such as the Opuntia ficus-indica, a plant of the Cactaceae family.

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The objective of this work was to evaluate the effects of enzymatic hydrolysis on digestibility and morphological and structural properties of hydrothermally pre-treated (HPT) red rice starch. The pre-treatments were performed in autoclave and cooking for the modification of rice grains and native starch. In vitro starch digestibility was performed consecutively and semi-simultaneously using α-amylase and amyloglucosidase.

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The objective of this study was to evaluate the modification of red rice starch by a combination of hydrothermal pretreatments and α-amylase hydrolysis. In vitro digestibility and the morphological, structural, functional, thermal, textural and rheological properties of red rice starch were evaluated. The starch submitted to autoclave (A3) obtained the highest hydrolysis yield (37.

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The Amazon rainforest has a rich biodiversity, and studies of Basidiomycete fungi that have biomolecules of biotechnological interest are relevant. The use of lignocellulosic biomass in biotechnological processes proposes an alternative use, and also adds value to the material when employed in the bioconversion of agro-industrial waste. In this context, this study evaluate the production of lignocellulolytic enzymes (carboxymethylcellulases (CMCase), xylanase, pectinase, laccase) as well as phenolic compounds and proteases by solid-state fermentation (SSF) using the fungus Lentinus strigosus isolated from Amazon.

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The use of β-galactosidase in food products has been a major focus of the industry. Therefore, the development of efficient and inexpensive methodologies to purify it is essential. Thus, this study aimed to recover the enzyme β-galactosidase (β-gal) by ion-exchange chromatography in a fixed-bed column.

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Carnauba (Copernicia prunifera) is a Brazilian palm tree used for wax production, which usually generates a large amount of waste. This work evaluated the carnauba waste for cellulase and xylanase production using Trichoderma reesei CCT2768 through a solid-state fermentation (SSF). Carnauba waste was used in its crude form (C-IN), pretreated (C-P) with alkaline hydrogen peroxide (AHP), and also recycled after the SSF process (C-PR).

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Chitooligosaccharides (COS) have a great potential to be used by pharmaceutical industry due to their many biological activities. The use of enzymes to produce them is very advantageous, however it still faces many challenges, such as discovering new strains capable to produce enzymes that are able to generate bioactive oligosaccharides. In the present study a purification protein protocol was performed to purify chitosanases produced by CCT 7899 for further chitosan hydrolysis.

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Hyaluronic acid (HA) is a biopolymer with applications in different areas such as medicine and cosmetics. HA is currently either isolated from animal sources or produced by microbial fermentation. Animal HA presents some disadvantages such as high cost and risk of viral cross-species or another infectious agent.

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The present study aimed to evaluate the lactose hydrolysis conditions from "coalho" cheese whey using β-galactosidase (β-gal) produced by immobilized with sodium alginate. Three sodium alginate-based immobilization systems were evaluated (0.5, 0.

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The present study evaluated the surfactin production by UFPEDA 438 using sugarcane molasses as a substrate. The effects of the cultivation conditions (temperature, agitation and aeration ratio) on the biosurfactant production and kinetic parameters were investigated. Characteristics of the biosurfactant were obtained after analyses of the emulsification index (EI) and critical micellar concentration (CMC) of the fermentation broth.

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The present study evaluated the co-production of β-galactosidase and ethanol by ATCC 36907 and NRRL Y-8279 using as carbon source the lactose found on "coalho" cheese whey. Cheese whey was subjected to partial deproteinization, and physicochemical parameters were assessed. Cultivations were carried out in an shaker to evaluate two carbon/nitrogen (C:N) ratios.

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Leishmaniosis is caused by the protozoa of the genus Leishmania with a wide spectrum of clinical and epidemiological manifestations which are characterized into four clinical groups: cutaneous, mucocutaneous, diffuse cutaneous, and visceral. American visceral leishmaniosis (AVL) or visceral leishmaniosis (VL) has been known as the most severe form of the disease. However, despite the growing number of people exposed to the infection risk and the great effort done by the scientific community worldwide to significantly increase the knowledge about these diseases, there is no vaccine capable of preventing VL in humans.

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The present study aimed to evaluate the influence of induction conditions (IPTG concentration, temperature, and induction time) on the plasmid pQE-30 stability and 503 antigen expression of Leishmania i. chagasi in Escherichia coli M15. Batch cultures were performed at 37 °C and induced by the addition of different IPTG concentrations (0.

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Ethanol production by simultaneous saccharification and fermentation (SSF) using sugarcane bagasse as substrate was developed using batch and fed-batch mode. Acid, alkali, hydrothermal and hydrogen peroxide pretreatments to the sugarcane bagasse were tested. Experiments were carried out to optimize the enzyme load of cellulases and β-glucosidase.

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Leishmaniosis is a complex of diseases that can be fatal, if not given proper attention. Despite its relevance in the public health system, there is no vaccine capable of preventing the disease in humans so far and its treatment is expensive and aggressive to human health. The present study aims to optimize the induction parameters of the 503 Leishmania i.

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This work investigated the influence of chemical (Triton X-100) and biological surfactant preparation (rhamnolipids) in coconut husk hydrolysis that was subjected to pretreatment with acid-alkali or alkaline hydrogen peroxide. The natural and pretreated biomass was characterized using the National Renewable Energy Laboratory protocol analysis as well as X-ray diffraction and scanning electron microscopy. The results demonstrated that in terms of the total reducing sugars, there was no significant difference between the hydrolysis using Triton X-100 and rhamnolipids, regardless of the pretreatment.

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In this study, a general rate model was applied to the entire process of expanded bed adsorption chromatography (EBAC) for the chitosanases purification protocol from unclarified fermentation broth produced by Paenibacillus ehimensis using the anionic adsorbent Streamline DEAE. For the experiments performed using the expanded bed, a homemade column (2.6cm×30.

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This study presents a system for expanded bed adsorption for the purification of chitosanase from broth extract in a single step. A chitosanase-producing strain was isolated and identified as Bacillus cereus C-01 and used to produce chitosanases. The expanded bed adsorption conditions for chitosanase purification were optimized statistically using STREAMLINE(TM) DEAE and a homemade column (2.

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A chitosanase-producing strain was isolated and identified as Bacillus cereus C-01. The purification and characterization of two chitosanases were studied. The purification assay was accomplished by ion exchange expanded-bed chromatography.

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Production of cellulosic ethanol and holocellulosic ethanol from vegetable or microbial biomass starts with a hydrolysate containing compounds which may produce negative effects in the enzymatic hydrolysis and fermentation stages due to the need of pretreatment of the materials. In this way, the simultaneous presence of hydroxymethylfurfural (HMF), furfural, acetic acid, levulinic acid, and formic acid in different concentrations was tested in the fermentation using Saccharomyces cerevisiae, Pichia stipitis, and Zymomonas mobilis. The substitution of freshwater by seawater in the culture medium was also analyzed.

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Visceral leishmaniasis, a disease caused by Leishmania infantum chagasi, represents a major public health problem in many areas of the world. However, there is currently no vaccine for human use. The aim of this work was to purify the 503 antigen of Leishmania i.

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