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1.
Food Chem ; 337: 127771, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32777564

RESUMO

Faveleira (Cnidoscolus quercifolius) is an emerging Brazilian plant, with seeds rich in edible oil. This study investigates physicochemical properties, chemical composition, thermal and oxidative stability, in vitro and in vivo toxicity, antioxidant, antinociceptive and anti-inflammatory activities of faveleira seed oil. It was observed that the oil has low acidity, value of peroxide, chlorophyll, carotenoids, ß-carotene and high concentrations of unsaturated fatty acids. In addition to presenting thermal and oxidative stability and high total phenolic content, with vanillin, eugenol and quercetin were predominating. The oil showed no toxicity in vitro and in vivo, and presented antioxidant, anti-inflammatory and antinociceptive activities. These findings provide relevant and appropriate conditions for processing of faveleira seed oil as functional food.

2.
Prep Biochem Biotechnol ; 50(9): 925-934, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32496939

RESUMO

The present study evaluated the co-production of ß-galactosidase and ethanol by Kluyveromyces marxianus ATCC 36907 and Kluyveromyces lactis 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. The best C:N ratio (1.5:1) was carried to 1.5-L bioreactor cultivation in order to increase co-production yields. The stability of ß-galactosidase was assessed against different temperatures and pH, and in the presence of metal ions. Concerning the co-production of ß-galactosidase and ethanol, K. lactis proved to be more efficient in both the C:N ratios, reaching 21.09 U·mL-1 of activity and 7.10 g·L-1 of ethanol in 16 h. This study describes the development of a viable and value-adding biotechnological process using a regional cheese by-product from Northeast Brazil for co-production of biomolecules of industrial interest.

3.
Appl Microbiol Biotechnol ; 104(10): 4273-4280, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32215706

RESUMO

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. In this short review, we present some of the plasmids used for the expression of recombinant protein by Escherichia coli strains used mainly for the second generation of vaccines for leishmaniosis. It can be emphasized that currently, these vectors and hosts play an important role in developing vaccine strategies against the disease. Indeed, use of the E. coli BL21 (DE) strain is remarkable mainly due to its characteristics for being a stable protein producer as well as the use of histidine tags for antigen purification. KEY POINTS: • Plasmid vectors and E. coli will continue being important for studies about leishmaniosis. • Protein purification exploiting histidine tags is a key technique.

4.
PLoS One ; 15(1): e0219229, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31895921

RESUMO

Reduction of waste from food industry and food services is a current concern due to the large amount of waste generated, including peels and fruit seeds. The objective of this study was to obtain a flour produced from Cantaloupe melon seeds (Cucumis melo L. var. reticulatus) and to evaluate the viability of using the product as an ingredient in cake manufacturing. In this study, different formulations were developed: standard cake-0% (F1) and cakes containing melon seed flour as substitute of wheat flour in 10% (F2), 30% (F3), and 50% (F4) concentrations. Centesimal composition, dietary fibre, structural and morphological characterization, determination of mineral composition, and evaluation of fatty acids profile in melon seed flour were carried out. To determine the overall acceptance of cake formulations, sensory analysis was performed with 135 non-trained panelists, which also included the identification of sensorial attributes using the Just About Right ideal scale test. The results showed that the melon seed flour has considerable nutritional value, with 18% proteins, 3% moisture, 4% ash, 30% lipids, and 35% dietary fibre. Melon flour also has a significantly high content of minerals, mainly phosphorus (1507.62 mg/100 g), potassium (957.35 mg/100 g), and magnesium (504.03 mg/100 g). The polyunsaturated fatty acid fraction was the most abundant in melon seed flour, with predominance of omega-6 fatty acids (17.95 g/mg of sample). Sensorial analysis disclosed good acceptance for formulations containing 10% and 30% of melon seed flour, with the 10% formulation being the most accepted. The research showed the feasibility of using the melon seed flour in cake production, as well as the possibility of using food waste in restaurants and food industries in order to adhere to sustainable production actions.


Assuntos
Cucumis melo/química , Farinha/análise , Sementes/química , Resíduos/análise , Brasil , Fibras na Dieta/análise , Ácidos Graxos Insaturados/análise , Análise de Alimentos , Humanos , Magnésio/análise , Valor Nutritivo , Fósforo/análise , Potássio/análise , Triticum/química
5.
Appl Microbiol Biotechnol ; 103(16): 6495-6504, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31218376

RESUMO

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 (0.01 to 1.5 mM). Subsequently, experiments were carried out at different temperatures (27 to 42 °C), evaluating the influence of induction time (0.5 to 6 h after the start of the culture). The results showed that IPTG toxicity caused a metabolic stress in the cells and, consequently, the microorganism growth reduced. The induction with IPTG may also be associated with the plasmid pQE-30 instability, due to metabolic burden imposed by the recombinant protein expression. The optimal conditions for 503 antigen expression of Leishmania i. chagasi in Escherichia coli M15 were an IPTG concentration of 1.0 mM, temperature of 37 °C, and induction time of 2 h. The maximum antigen concentration obtained was 0.119 ± 0.009 g/L, about seven times higher than the lowest concentration. Therefore, the results showed that 503 antigen can be produced in laboratory; however, it requires more studies to minimize the plasmid instability and improve to industrial scale.


Assuntos
Antígenos de Protozoários/biossíntese , Escherichia coli/metabolismo , Expressão Gênica , Leishmania/genética , Proteínas Recombinantes/biossíntese , Ativação Transcricional , Antígenos de Protozoários/genética , Escherichia coli/genética , Instabilidade Genômica/efeitos dos fármacos , Isopropiltiogalactosídeo/metabolismo , Plasmídeos , Proteínas Recombinantes/genética , Temperatura
6.
Prep Biochem Biotechnol ; 48(10): 968-976, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30489218

RESUMO

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. chagasi antigen expressed in recombinant Escherichia coli M15. The induction at different cell densities was evaluated in order to analyze the influence of the induction time on the yield of the protein of interest. In this segment, lactose and isopropyl-ß-d-thiogalactopyranoside (IPTG) were used as inducer molecules, using various concentrations: 0.1 g/L, 1.0 g/L, and 10 g/L for lactose and 20 µM, 100 µM, 500 µM, and 1000 µM for IPTG. The results presented that the concentration of IPTG that obtained the higher antigen levels was that of 100 µM (0.087 g/L), a 10-fold lower concentration than was being previously used in this type of system and for lactose, it was 1 g/L (0.016 g/L). Thus, the induction with 100 µM allowed obtaining the antigen with a concentration 5.6 times higher than the lactose induction maximum concentration.


Assuntos
Antígenos de Protozoários , Escherichia coli/metabolismo , Expressão Gênica , Leishmania infantum , Antígenos de Protozoários/biossíntese , Antígenos de Protozoários/genética , Antígenos de Protozoários/imunologia , Antígenos de Protozoários/isolamento & purificação , Escherichia coli/genética , Humanos , Leishmania infantum/genética , Leishmania infantum/imunologia , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/isolamento & purificação
7.
Bioresour Technol ; 237: 20-26, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28411051

RESUMO

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. A cellulosic conversion value as high as 33.0% was obtained in experiments with rhamnolipids. The coconut husk was observed to be a potential biomass that could produce second generation ethanol, and the rhamnolipid preparation can be used to support for the enzymatic hydrolysis, enhancing the advantage of cellulose conversion into glucose over chemical surfactants because it is an environmentally friendly approach.


Assuntos
Cocos , Glicolipídeos , Hidrólise , Pseudomonas aeruginosa , Biomassa , Celulose
8.
Artigo em Inglês | MEDLINE | ID: mdl-25703945

RESUMO

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. chagasi directly from unclarified Escherichia coli feedstock through expanded bed adsorption (EBA) chromatography. Batch experiments were performed to optimize the adsorption and elution conditions of the antigen onto a STREAMLINE Chelating resin using two central composite rotatable designs (CCRD). The results showed that the optimal binding conditions of the 503 antigen were pH 8.0 in the presence of 2.4 M NaCl. For the elution of the target protein, the optimized conditions included the presence of 600.0 mM imidazole. The adsorption isothermal data of the 503 antigen were fitted to the Langmuir adsorption isotherm. The EBA experiment successfully recovered 59.2% of the 503 antigen from the unclarified E. coli homogenate with a purification factor of 6.0.


Assuntos
Antígenos de Protozoários/isolamento & purificação , Cromatografia de Afinidade/métodos , Leishmania infantum , Proteínas Recombinantes/isolamento & purificação , Adsorção , Antígenos de Protozoários/química , Escherichia coli/metabolismo , Modelos Lineares , Proteínas Recombinantes/química
9.
Braz J Microbiol ; 42(4): 1296-9, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24031755

RESUMO

In the present study, we determined the frequency of superficial and cutaneous mycoses and their etiologic agents during a 7-year period (2002-2008) in Natal, Brazil. A total of 1,717 specimens of skin, nail, and hair were collected from 1,382 patients with suspected mycoses lesions and were then subjected to direct microscopy and culture.

10.
Braz J Microbiol ; 42(4): 1390-6, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24031768

RESUMO

With the advent of recombinant DNA technology, recombinant protein expression has become an important tool in the study of the structure, function and identification of new proteins, especially those with therapeutic functions. Escherichia coli has been the predominant prokaryote used in genetic engineering studies due to the abundance of information about its metabolism. Despite significant advances in molecular biology and immunology of infections, there are as yet no prophylactic drugs capable of preventing visceral leishmaniasis. It is therefore important to identify specific antigens in order to develop vaccines and diagnostic kits against this disease. The objective of this study was to evaluate the influence of culture medium on the production of eIF antigen from Leishmania chagasi in recombinant Escherichia coli. An induction procedure using IPTG was carried out in a series of trials, to observe the influence of culture medium (2xTY, TB) under expression of the recombinant eIF protein. Results showed that recombinant protein expression was associated to growth and that the highest eIF antigen expression was obtained in the 2xTY medium.

11.
Braz J Microbiol ; 41(2): 316-20, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24031498

RESUMO

Many methods have been described for the detection of methicillin-resistant Staphylococcus aureus (MRSA), but the heterogeneous expression of methicillin resistance affects the reliability of these methods. The aim of the present study was to evaluate some methods for detecting methicillin resistance in Staphylococcus aureus isolates in a university hospital located in the Northeast of Brazil. Among the isolates, 15 were methicillin-susceptible and 45 were methicillin-resistant, including low-level heterogeneous resistance strains. Both the 30 ηg-cefoxitin disk and PBP2a test had 100% sensibility/specificity and appear to be good options for the detection of MRSA in the clinical laboratory.

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