Publications by authors named "Sandra A De Assis"

Unlabelled: Β-glucosidase (BGLs) act synergistically with endoglucanases and exoglucanases and then are of great interest for biomass conversion into bioethanol. Thus, the aim of the current study is to produce a recombinant β-glycosidase from expressed in cells. Enzyme coding sequence expression was confirmed through Sanger sequencing after using wheat bran (WB) and carboxymethylcellulose (CMC) as fungal growth media.

View Article and Find Full Text PDF

is a methylotrophic yeast with wide geographical distribution. In the present study, the microorganism was isolated from the Bahian semiarid and the enzymatic extract containing β-glucosidase was obtained through submerged fermentation. Response surface methodology was employed to optimize of fermentation medium.

View Article and Find Full Text PDF

β-glucosidase is an essential enzyme for the enzymatic hydrolysis of lignocellulosic biomass, as it catalyzes the final stage of cellulose breakdown, releasing glucose. This paper aims to produce β-glucosidase from and evaluate the enzymatic degradation of delignified sugarcane bagasse. was grown in yeast peptone dextrose medium.

View Article and Find Full Text PDF

The management of inflammatory states typically involves non-steroidal anti-inflammatory drugs (NSAIDs) and opiates. Understanding the mechanisms underlying the processing of nociceptive information from potential alternatives such as some polysaccharides may enable new and meaningful therapeutic approaches. In this study, α-D-mannan isolated from the Kluyveromyces marxianus cell wall produced antinociceptive effects in models of inflammatory pain (formalin and complete Freund's adjuvant tests).

View Article and Find Full Text PDF

Guava juice is cloudy and viscous, which hinders filtration, decreases yield, and causes the loss of quality after its processing and during storage. This study aimed to evaluate enzymatic treatment effects using crude multi-enzymatic extracts (CME) obtained from Rhodotorula mucilaginosa, Rhodotorula orizycola, and Pseudozyma sp. produced by submerse fermentation in the extraction of juice guava.

View Article and Find Full Text PDF

β-Glucosidase is widely used in several industrial segments, among which we can highlight the pharmaceutical industry, beverages, biofuels, animal feed production, and the textile industry. The great applicability of this enzyme, associated with the high cost of its production, justifies the need to find ways to make its use economically viable on an industrial scale. Through enzyme immobilization, the biocatalyst can be reused more than once, without great impact on its catalytic activity, and higher operational and storage stabilities can be achieved as compared to the free form.

View Article and Find Full Text PDF

Mannans has been attracted the interest in various sectors due to its promising applications. The low toxicity of mannans allows for their use in cosmetics, pharmaceutical, and biomedical industries. In this study, the α-D-mannan extraction conditions from by alkaline extraction were optimized using a Box-Behnken design (BBD).

View Article and Find Full Text PDF

The crude extract containing inulinase from was obtained by submerged fermentation. Inulinase was immobilized on chicken eggshell by physical adsorption and covalent crosslinking, using glutaraldehyde as a crosslinking reagent, and Celite by adsorption. Fructooligosaccharides production was performed using immobilized inulinase (5%, w/v) and inulin substrate solution under experimental conditions evaluated through Doehlert experimental design.

View Article and Find Full Text PDF

Tangerine juice was treated with crude extract containing cellulase from sp. obtained by liquid fermentation. The thermal stability of cellulase was investigated by incubating crude extract at different temperatures and times.

View Article and Find Full Text PDF

Unlabelled: sp. are yeasts that are commercially important due to their production of glycolipid biosurfactants, squalene, itaconic acid, and exopolysaccharide. The search for other analgesia inducing drugs, such as opiates and non-steroidal anti-inflammatory drugs (NSAIDs), as alternatives is beneficial.

View Article and Find Full Text PDF

Protease was extracellularly produced in submerged fermentation by the fungus with maximum activity of 8.6 × 10 U/mL. The optimal pH and temperature for enzyme activity were 6.

View Article and Find Full Text PDF

The protease was produced extracellularly in submerged fermentation by the yeast Rhodotorula oryzicola using different sources of nitrogen and maximum activity (6.54 × 10 U/mg) was obtained in medium containing 2% casein (w/v). Purification of the protease by gel filtration chromatography resulted in a 3.

View Article and Find Full Text PDF

The current study aims to assess the kinetics of population growth of Rhodotorula oryzicola and the production of β-1,3-glucanase (EC 3.2.1.

View Article and Find Full Text PDF

Tannase can be used in different industrial sectors such as in food (juices and wine) and pharmaceutical production (trimethoprim) because it catalyses the hydrolysis of hydrolysable tannins. The aim of the current study is to assess the tannase found in the crude extract of Saccharomyces cerevisiae CCMB 520, and to set its catalytic and thermodynamic properties. The enzyme was optimally active at pH 6.

View Article and Find Full Text PDF

The aims of the current study are to assess the influence of polyethylene glycol (PEG) concentration, molar mass, pH, and citrate concentrations on aqueous biphasic systems based on 2 factorial designs, as well as to check their capacity to purify tannase secreted by Aspergillus tamarii URM 7115. Tannase was produced through submerged fermentation at 26°C for 67 h in Czapeck-Dox modified broth and added with yeast extract and tannic acid. The factorial design was followed to assess the influence of PEG molar mass (M 600; 4,000 and 8,000 g/ mol), and PEG (C 20.

View Article and Find Full Text PDF

Endoglucanase production by Aspergillus oryzae ATCC 10124 cultivated in rice husks or peanut shells was optimized by experimental design as a function of humidity, time, and temperature. The optimum temperature for the endoglucanase activity was estimated by a univariate analysis (one factor at the time) as 50°C (rice husks) and 60°C (peanut shells), however, by a multivariate analysis (synergism of factors), it was determined a different temperature (56°C) for endoglucanase from peanut shells. For the optimum pH, values determined by univariate and multivariate analysis were 5 and 5.

View Article and Find Full Text PDF

The current study aims to extract bromelain from different parts (stem, crown, peels, pulp and leaves) of Ananas comosus var. comosus AGB 772; to determine of optimum pH and temperature; to test bromelain stability in disodium EDTA and sodium benzoate, and to investigate its pharmacological activity on B16F10 murine melanoma cells in vitro. The highest enzymatic activity was found in bromelain extracted from the pulp and peel.

View Article and Find Full Text PDF

β-d-glucans are polymers of d-glucose monomers found in the cell walls of many bacteria, plants, fungi and yeasts. A variety of β-d-glucans differing in structures have been isolated from various sources and their biological activity to be regulated by various structural factors, such as the primary structure, molecular weight, solubility, and conformation. This study investigated the effect of extraction time and temperature on the yield of β-d-glucan produced by Rhodotorulamucilaginosa.

View Article and Find Full Text PDF

Background: The witches' broom disease is a plague caused by Moniliophthora perniciosa in the Theobroma cacao, which has been reducing the cocoa production since 1989. This issue motivated a genome project that has showing several new molecular targets, which can be developed inhibitors in order to control the plague. Among the molecular targets obtained, the UDP-N-acetylglucosamine pyrophosphorylase (UNAcP) is a key enzyme to construct the fungal cell wall.

View Article and Find Full Text PDF

In this work, sisal waste was used as a source of pectin. Sisal is known worldwide as a source of hard fibres, and Brazil is the largest producer of sisal, producing more than 246,000 tonnes. However, the process of removing the fibres of the sisal leaf generates 95% waste.

View Article and Find Full Text PDF

The genus Leuconostoc belongs to a group of lactic acid bacteria usually isolated from fermented vegetables, which includes species involved in the production of exopolysaccharides (EPS). These biopolymers possess considerable commercial potential. Because of the wide variety of industrial applications of EPS, this study aimed to produce and characterize the native exopolysaccharide strain Leuconostoc pseudomesenteroides R2, which was isolated from cabbage collected in a semi-arid region of Bahia.

View Article and Find Full Text PDF

The enzyme chitinase from Moniliophthora perniciosa the causative agent of the witches' broom disease in Theobroma cacao, was partially purified with ammonium sulfate and filtration by Sephacryl S-200 using sodium phosphate as an extraction buffer. Response surface methodology (RSM) was used to determine the optimum pH and temperature conditions. Four different isoenzymes were obtained: ChitMp I, ChitMp II, ChitMp III and ChitMp IV.

View Article and Find Full Text PDF

Moniliophthora perniciosa (Sthael) (Singer) Phillips-Mora is the causal agent of witches' broom disease, which can infect Theobroma cacao decreasing the production of cocoa about 60%. M. perniciosa has a set of potential enzymes that can be useful targets for design of new inhibitors.

View Article and Find Full Text PDF

The antioxidant activity, ascorbic acid and phenolic content were studied in 10 exotic fruits from Brazil: abiu, acerola, wax jambu, cashew, mamey sapote, carambola or star fruit, Surinam cherry, longan, sapodilla and jaboticaba. The ascorbic acid was determined by 2,6-dichloroindophenol titrimetic methods and total phenols were measured colorimetrically using the Folin-Ciocalteu reagent. The antioxidant activity was investigated with three different methods: hypochlorous acid scavenging activity, 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation decolorization assay, and 2,2-diphenyl-1-picrylhydrazyl radical scavenging method.

View Article and Find Full Text PDF