Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.798
Filtrar
1.
An Acad Bras Cienc ; 91(3): e20180735, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31553366

RESUMO

Candida haemulonii complex (C. haemulonii, C. haemulonii var. vulnera and C. duobushaemulonii) consists of emergent multidrug-resistant pathogens that cause bloodstream and deep-seated infections. However, little is known about their virulence factors. Herein, we evaluated the presence of extracellular serine peptidases in this fungal complex. Serine peptidase activity was measured by spectrophotometry using chromogenic peptide substrates to the S1 family. Chymotrypsin-, trypsin- and elastase-like activities were detected in all fungal isolates. Since higher chymotrypsin- and trypsin-like activities were observed from the cleavage of N-succinyl-Ala-Ala-Pro-Phe-pNa and N-benzoyl-Phe-Val-Arg-pNa, respectively, these substrates were selected for further experiments. Overall, pHs 7.0 and 9.0 were those in which higher chymotrypsin- and trypsin-like activities were observed, respectively, displaying higher hydrolytic activities at 37-45°C. Additionally, the serine peptidases produced by C. haemulonii complex were inhibited by PMSF and AEBSF in a typically concentration-dependent manner. Although the Michaelis constant (Km) values obtained for chymotrypsin-like peptidases were similar, greater differences were observed for trypsin-like enzymes secreted by the different fungal isolates. This is the first time that peptidases belonging to the S1 family are described in the C. haemulonii species complex. Thus, these data open the doors for more detailed studies into potential roles of these peptidases in fungal virulence.


Assuntos
Candida/enzimologia , Quimotripsina/metabolismo , Farmacorresistência Fúngica Múltipla , Tripsina/metabolismo , Candida/classificação , Meios de Cultura , Espectrofotometria , Temperatura Ambiente
2.
J Enzyme Inhib Med Chem ; 34(1): 1474-1480, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31414611

RESUMO

The discovery of allosteric modulators is a multi-disciplinary approach, which is time- and cost-intensive. High-throughput screening combined with novel computational tools can reduce these factors. Thus, we developed an enzyme activity assay, which can be included in the drug discovery work-flow subsequent to the in-silico library screening. While the in-silico screening yields in the identification of potential allosteric modulators, the developed in-vitro assay allows for the characterisation of them. Candida rugosa lipase (CRL), a glyceride hydrolysing enzyme, has been selected for the pilot development. The assay conditions were adjusted to CRL's properties including pH, temperature and substrate specificity for two different substrates. The optimised assay conditions were validated and were used to characterise Tropolone, which was identified as an allosteric modulator. In conclusion, the assay is a reliable, reproducible, and robust tool, which can be streamlined with in-silico screening and incorporated in an automated high-throughput screening workflow.


Assuntos
Lipase/metabolismo , Miniaturização , Regulação Alostérica , Candida/enzimologia , Cristalografia por Raios X , Estabilidade Enzimática , Ensaios de Triagem em Larga Escala , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Cinética , Limite de Detecção , Lipase/química , Reprodutibilidade dos Testes , Especificidade por Substrato , Temperatura Ambiente
3.
Food Chem ; 297: 124925, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253266

RESUMO

A novel lipase gene (McLipB) was cloned from a thermophilic fungus Malbranchea cinnamomea and expressed in Pichia pastoris. The deduced amino acid sequence of the lipase (McLipB) shared the highest identity of 46% with the Candida rugosa lipase LIP4. The extracellular lipase activity of 4304 U/mL with protein concentration of 7.7 mg/mL was achieved in a 5-L fermentor. The optimal pH and temperature of McLipB were 7.5 and 40 °C, respectively. The lipase showed high specificity towards triglycerides with short and medium chain fatty acids, and had non-position specificity. McLipB hydrolyzed butter to produce mainly butyric acid, hexanoic acid and a small amount of octanoic acid and decanoic acid. Furthermore, it degraded more than 90% dipropyl phthalate, dibutyl phthalate and dihexyl phthalate to their corresponding monoalkyl phthalates. The properties of McLipB indicate that it has great application potential for production of lipolyzed milkfat flavor and biodegradation of phthalate esters.


Assuntos
Ascomicetos/enzimologia , Lipase/metabolismo , Sequência de Aminoácidos , Técnicas de Cultura Celular por Lotes , Candida/enzimologia , Concentração de Íons de Hidrogênio , Hidrólise , Lipase/química , Lipase/genética , Ácidos Ftálicos/química , Ácidos Ftálicos/metabolismo , Pichia/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Alinhamento de Sequência , Especificidade por Substrato , Temperatura Ambiente , Triglicerídeos/metabolismo
4.
Rev Fac Cien Med Univ Nac Cordoba ; 76(2): 107-112, 2019 06 19.
Artigo em Espanhol | MEDLINE | ID: mdl-31216165

RESUMO

In the last half century there was a significant increase in the incidence of fungal infections being likely to become a global health priority. The sophisticated degree of host-Candida interaction is the product of different virulence strategies used by the fungus to invade the tissues and the various defense mechanisms that it develops to control it. There is a significant amount of literature that indicates that this opportunistic commensal fungus has components that can be considered virulence factors related to the stage of the infectious process. Among the virulence factors of this fungus can be mentioned the adherence to cell surfaces, the formation of biofilms and the production of hydrolytic enzymes. The most studied hydrolases secreted by C. albicans are aspartyl proteinases, phospholipases and esterases, while lipases have been the least studied. These enzymes would have the function to facilitate active penetration into the cells, participating in the digestion and synthesis of lipid esters for their nutrition and contributing to the invasion of the tissue by hydrolyzing the lipid components of the host cell membranes. There is also bibliographic evidence that these enzymes are capable to damage cells and molecules of the immune system to avoid the antimicrobial activity.Taking into account the foregoing, this review provides an updated description of biochemical and molecular characteristics of the lipases secreted by Candida, its role as a virulence factor and its potential for the development of new antifungal drugs.


Assuntos
Candida/enzimologia , Lipase , Candida/patogenicidade , Humanos , Lipase/química , Lipase/classificação , Lipase/genética , Lipase/fisiologia , Fatores de Virulência
5.
Chemosphere ; 233: 132-139, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31170583

RESUMO

Oil sludge is one kind of toxic and persistent contamination to ecology system from petroleum industry. In order to recycle contaminated sands and reduce environmental impacts at a lower operating cost, enzyme cocktail 21/CbFDH including NADH regeneration system for oily sludge bioremediation was constructed for the first time. The intracellular enzymes of oil-degrading strain Acinetobacter calcoaceticus 21 were prepared and the formate dehydrogenase gene Cbfdh from Candida boidinii was cloned and functionally expressed in E.coli BL21 induced by lactose. The activity and stability of CbFDH was enhanced through self-induction medium optimization using Box-Behnken design. The CbFDH activity was 12.2 times increased and was only decreased 3.9% upon storage at 30 °C for 5 d. The CbFDH increased the degradation rate of oil in high concentration. For the sludge with 10% oil (w/w), the degradation rate achieved 35.6% after 12 h using enzyme 21/CbFDH with the protein ratio of 1:4. The results will provide novel perspectives for creation and operation of petroleum-degrading enzymes involving formate dehydrogenase with higher efficiency and lower cost comparing to current microbial strains or consortium.


Assuntos
Formiato Desidrogenases/metabolismo , NAD/metabolismo , Petróleo/metabolismo , Esgotos , Acinetobacter calcoaceticus/enzimologia , Acinetobacter calcoaceticus/metabolismo , Biodegradação Ambiental , Candida/enzimologia , Candida/genética , Recuperação e Remediação Ambiental/métodos , Escherichia coli/genética , Formiato Desidrogenases/genética
6.
Chem Commun (Camb) ; 55(50): 7155-7158, 2019 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-31134258

RESUMO

Herein, the first example of crackled organosilica nanocapsules (CONs) is reported to directly immobilize enzymes without any further chemical modification. Enzymes are adsorbed on both the exterior and interior surfaces of CONs, integrating the merits of adsorption and encapsulation. When used for Candida rugosa lipase (CRL) immobilization, the CONs displayed higher enzyme loading, lower enzyme leaching, and elevated enzyme activity, compared to the conventional non-crackled nanocapsules/particles.


Assuntos
Candida/enzimologia , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Lipase/metabolismo , Nanocápsulas/química , Compostos de Silício/química , Lipase/química
7.
Int J Biol Macromol ; 133: 1042-1050, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31042560

RESUMO

In this study, iron magnetic nanoparticles capped with fluorescent calixarene derivatives (Fe3O4@Calix-2 and Fe3O4@Calix-3) were prepared in one-step using coprecipitation of Fe(II) and Fe(III) in basic solution. Different techniques were used to characterize the synthesized magnetic nanoparticles, such as Fourier Transform Infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and confocal microscopy. Candida rugosa was encapsulated on synthesized nanoparticles following sol-gel method. It has been observed that under the optimum conditions, the activity of encapsulated lipase (Fe3O4@Calix-2E) was 119 U/g of support which is 4.1 times more that of the encapsulated lipase without calix[4]arene derivative (Fe3O4@E). Comparative study show that the encapsulated lipase on nanoparticles has higher thermal and operational stability than encapsulated lipase without calix[4]arene derivative. Among these encapsulated lipase nanoparticles, Fe3O4@Calix-2 was capable of effectively catalyze hydrolysis of racemic Flurbiprofen methyl ester with high conversion of 49% and substrate enantiomeric excess (ees) of 85% at optimum pH and temperature. The efficiency of these nanoparticles was assessed by their reusability, for that after five consecutive operational uses these encapsulated lipase nanoparticles retained their conversion ratios up to 38% and 30% respectively, in the hydrolysis of (R,S)-Flurbiprofen methyl ester. The results showed that encapsulated lipases nanoparticle with calixarene moieties lead to increased activity, stability, reusability and enhanced stereoselectivity in kinetic resolution.


Assuntos
Calixarenos/química , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Óxido Ferroso-Férrico/química , Corantes Fluorescentes/química , Lipase/química , Lipase/metabolismo , Fenóis/química , Candida/enzimologia , Cápsulas , Estabilidade Enzimática , Flurbiprofeno/química , Flurbiprofeno/metabolismo , Concentração de Íons de Hidrogênio , Hidrólise , Estereoisomerismo , Especificidade por Substrato , Temperatura Ambiente
8.
Enzyme Microb Technol ; 126: 77-85, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31000167

RESUMO

(R)-pantolactone is a key chiral intermediate for synthesizing calcium (R)-pantothenate. The commercial synthesis of (R)-pantolactone is performed through the resolution of racemic pantolactone using lactonase-catalyzed enantioselective hydrolysis. The process needs highly toxic hydrogen cyanide and a tedious dynamic kinetic resolution. In this study, we investigated an alternative method to prepare (R)-pantolactone through asymmetric reduction of ketopantolactone (KPL). An NADPH-dependent conjugated polyketone reductase gene from Candida dubliniensis CD36 (CduCPR) was functionally overexpressed in Escherichia coli BL21 (DE3). Recombinant CduCPR belonged to the aldo-keto reductase superfamily, and showed high catalytic activity and stereoselectivity using KPL as the substrate. In a continuous feeding reaction, 200 mM ketopantolactone was reduced to (R)-pantolactone with 98% conversion and 99% enantiomeric excess (e.e.) within 2.0 h. The catalytic mechanism was further investigated. Tyr66 functions as a proton donor following hydrogen transfer from NADPH. Thr30 and His128 are critical residues to bind and orient KPL. Therefore, the recombinant CduCPR from C. dubliniensis exhibited potential application in the asymmetric synthesis of (R)-pantolactone.


Assuntos
4-Butirolactona/análogos & derivados , Oxirredutases do Álcool/metabolismo , Candida/enzimologia , Proteínas Fúngicas/metabolismo , NADP/metabolismo , Proteínas Recombinantes/metabolismo , 4-Butirolactona/metabolismo , Oxirredutases do Álcool/química , Oxirredutases do Álcool/genética , Sequência de Aminoácidos , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , NADP/química , Conformação Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Homologia de Sequência de Aminoácidos , Estereoisomerismo
9.
Curr Microbiol ; 76(6): 706-712, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30963198

RESUMO

It is well known that cofactors play a key role in the production of different compounds in bioconversion processes, while the high cost of cofactors limits their usage in industrial applications. In the present study, a NADH regeneration system was successfully developed in Lactobacillus plantarum by expressing the fdh gene coding for formate dehydrogenase (FDH) from Candida boidinii. Results indicated that the FDH was expressed with the highest activity of 0.82 U/mg of protein when cells entered early stationary phase. In addition, the expression of FDH increased the intracellular level of NADH and NADH/NAD+ ratio in L. plantarum, and therefore, enhanced the NADH-dependent production of 3-phenyllactic acid (PLA) in repeated and fed-batch bioconversions. In brief, the results demonstrate that the NADH regeneration by expressing FDH is a promising strategy for producing NADH-dependent microbial metabolites in L. plantarum.


Assuntos
Coenzimas/metabolismo , Formiato Desidrogenases/metabolismo , Lactatos/metabolismo , Lactobacillus plantarum/enzimologia , Lactobacillus plantarum/metabolismo , NAD/metabolismo , Candida/enzimologia , Candida/genética , Formiato Desidrogenases/genética , Expressão Gênica , Perfilação da Expressão Gênica , Lactobacillus plantarum/genética , Lactobacillus plantarum/crescimento & desenvolvimento , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
10.
Bioelectrochemistry ; 128: 148-154, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31003053

RESUMO

Antifungal substances that are used for the treatment of candidiasis have considerable side effects and Candida yeasts are known to obtain drug resistance. The multidrug resistance cases are promoting the search for the new alternative methods and pulsed electric field (PEF) treatment could be the alternative or could be used in combination with conventional therapy for the enhancement of the effect. We have shown that nanosecond range PEF is capable to induce apoptosis in the S. cerevisiae as well as in the drug resistant C. lusitaniae and C. guilliermondii. Supplementing the PEF procedure with formic acid (final concentration 0.05%) resulted in improvement of the inactivation efficacy and the induction of apoptosis in the majority of the yeast population. After the treatment yeast were displaying the DNA strand brakes, activation of yeast metacaspase and externalization of phosphatidylserine. Apoptotic phenotypes were registered already after 30 kV/cm × 250 ns × 50 pulses treatment. The highest number of apoptotic yeast cells (>60%) was obtained during the 30 kV/cm × 750 ns × 50 pulses protocol when combined with 0.05% formic acid. The results of our study are useful for development of new non-toxic and effective protocols to induce programed cell death in different yeast species and thus minimize inflammation of the tissue.


Assuntos
Apoptose/efeitos dos fármacos , Candida/efeitos dos fármacos , Caspases/metabolismo , Eletroporação/métodos , Formiatos/farmacologia , Saccharomyces cerevisiae/efeitos dos fármacos , Candida/classificação , Candida/citologia , Candida/enzimologia , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/enzimologia , Especificidade da Espécie
11.
J Biotechnol ; 296: 1-6, 2019 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-30853640

RESUMO

In this study, a commercial lipase derived from Candida cylindracea was chemically modified with dextran by conjugating ε-amine in the lysine residue with the carbonyl residue in oxidized dextran using the borane-pyridine complex as a reducing agent to increase the hydrophilicity of the microenvironment around the lipase in the presence of organic solvents. The degree of modification (53.2%), amount of dextran (0.66 g/g-lipase), specific activity (similar to that of the unmodified lipase), and stability in the presence of ethanol and 2-propanol (the half-lives were 2.24 and 1.86 times longer than those of the unmodified lipase) were higher for the lipase modified at pH 8.0 than for the lipases modified at other pH levels. Following modification with dextran at pH 8.0, the stability of the modified lipase was higher than that of the unmodified lipase in the presence of 25% (v/v) DMSO, ethanol, 2-propanol, toluene, n-hexane, and isooctane (the half-lives were 1.45, 2.24, 1.86, 1.76, 2.67 and 2.95 times longer than those of the unmodified lipase). Therefore, chemical modification with polysaccharides such as dextran using the borane-pyridine complex as a reducing agent could be a promising approach for improving the organic solvent stability of enzymes.


Assuntos
Candida/enzimologia , Estabilidade Enzimática/efeitos dos fármacos , Lipase/química , Solventes/química , Boranos/química , Dextranos/química , Compostos Orgânicos/química , Compostos Orgânicos/farmacologia , Piridinas/química , Solventes/farmacologia
12.
Int J Biol Macromol ; 131: 989-997, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30917914

RESUMO

Lipase B from Candida antarctica (CALB), lipase from Rhizomucor miehei (RML) and phospholipase Lecitase Ultra (LEU) were immobilized via interfacial activation and their stabilities were compared. Immobilized CALB was much more stable than immobilized RML or LEU. That meant that, if they were coimmobilized, after the inactivation of the least stable lipases, CALB should be discarded even though it may maintain full activity. This could be solved by sequential coimmobilization on octyl-glyoxyl (OCGLX). First, CALB was immobilized on OCGLX getting some covalent bonds between most of the CALB molecules and the support. Then, after reduction of CALB immobilized on OCGLX, RML or LEU can be immobilized on the support via interfacial activation. These enzymes could be released from the support just by using detergents, without affecting CALB activity. After optimization of the lipase desorption conditions, the bi-combilipases CALB/RML and CALB/LEU or the triple-combilipase CALB/RML/LEU could be submitted to several cycles of immobilized biocatalyst inactivation, desorption and enzyme reloading keeping the activity of the immobilized CALB almost intact. This way, by using OCGLX and a stepwise immobilization protocol, discarding all coimmobilized lipases when one becomes inactivated is no longer required. Thus, the most stable ones can be reused in several cycles.


Assuntos
Enzimas Imobilizadas , Glioxilatos/química , Lipase/química , Sefarose/química , Biocatálise , Candida/enzimologia , Detergentes/farmacologia , Ativação Enzimática/efeitos dos fármacos , Estabilidade Enzimática , Proteínas Fúngicas/química , Cinética
13.
J Mycol Med ; 29(2): 132-139, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30876744

RESUMO

BACKGROUND: Yeasts of the Candida genus are one of the most common causes of bloodstream infections associated with high rates of morbidity and mortality, mainly affecting immunocompromised patients. We aimed to identify yeasts obtained from blood cultures of patients interned at tertiary hospitals in Brazil. METHODS: We evaluated some of the major virulence factors of Candida spp., including the ability to adhere to human buccal epithelial cells, biofilm formation, hemolytic and phospholipase activity. RESULTS: We analyzed 70 isolates of Candida spp. obtained from March 2011 and March 2015. Candida spp. showed different peculiarities in terms of expression of virulence factors evaluated in vitro. C. albicans strains were more adherent to HBEC than all the other Candida species. C. tropicalis strains were considered strong biofilm producers. Strains belonging to the C. parapsilosis species complex were able to produce hemolysins, while C. glabrata was also able to lyse erythrocytes and to produce phospholipase. CONCLUSION: These results suggest that Non-Candida albicans Candida species are also able to express virulence factors which play an important role in bloodstream infectious caused by these yeasts.


Assuntos
Candida/isolamento & purificação , Candida/patogenicidade , Candidemia/epidemiologia , Fatores de Virulência/metabolismo , Biofilmes/crescimento & desenvolvimento , Hemocultura , Brasil/epidemiologia , Candida/enzimologia , Candida albicans/isolamento & purificação , Candida albicans/patogenicidade , Candida glabrata/isolamento & purificação , Candida glabrata/patogenicidade , Candidemia/microbiologia , Células Epiteliais/microbiologia , Proteínas Hemolisinas/metabolismo , Humanos , Boca , Fosfolipases/metabolismo , Centros de Atenção Terciária
14.
Mater Sci Eng C Mater Biol Appl ; 99: 25-36, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30889698

RESUMO

Herein, as a promising support, a magnetic enzyme nanoformulation have been designed and fabricated by a poly-o-toluidine modification approach. Owing to the magnetic nature and the existence of amine functionalized groups, the as-synthesised poly(o-toluidine) functionalized magnetic nanocomposite (Fe3O4@POT) was employed as potential support for Candida rugosa lipase (CRL) immobilization to explore its application in fruit flavour esters synthesis. The morphology and structure of the Fe3O4@POT NC were examined through various analytical tools. Hydrolytic activity assays disclose that immobilized lipase demonstrated an activity yield of 120%. It is worth mentioning that CRL#Fe3O4@POT showed superior resistance to extremes of temperature and pH and different organic solvents in contrast to free CRL. The magnetic behaviour of the as-synthesised NC was affirmed by alternating gradient magnetometer analysis. It was found to own facile immobilization process, enhanced catalytic performance for the immobilized form which may be stretched to the immobilization of various vital industrial enzymes. Moreover, it retained improved recycling performance. After 10 cycles of repetitive uses, it still possessed around 90% of its initial activity for the hydrolytic reaction, since the enzyme-magnetic nanoconjugate was effortlessly obtained using a magnet from the reaction system. The formulated nanobiocatalyst was selected for the esterification reaction to synthesize the fruit flavour esters, ethyl acetoacetate and ethyl valerate. The immobilized lipase successfully synthesised flavour compounds in aqueous and n-hexane media having significant higher ester yields compared to free enzyme. The present work successfully combines an industrially prominent biocatalyst, CRL, and a novel magnetic nanocarrier, Fe3O4@POT, into an immobilized nanoformulation with upgraded catalytic properties which has excellent potential for practical industrial implications.


Assuntos
Biocatálise , Enzimas Imobilizadas/metabolismo , Lipase/metabolismo , Nanopartículas de Magnetita/química , Nanocompostos/química , Toluidinas/química , Candida/enzimologia , Difusão Dinâmica da Luz , Estabilidade Enzimática , Esterificação , Ésteres/análise , Frutas/química , Concentração de Íons de Hidrogênio , Cinética , Solventes , Espectroscopia de Infravermelho com Transformada de Fourier
15.
Int J Pharm ; 562: 180-186, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30898639

RESUMO

The aim of this study was to develop and evaluate a self-emulsifying delivery system (SEDDS) for oral rutin fatty ester administration and to improve its mucus permeating properties by the incorporation of the silicon polymer poly [dimethylsiloxane-co-(3-(2-(2-hydroxyethoxy)ethoxy)propyl]methylsiloxane] (PDMSHEPMS) in the formulation. In order to increase the lipophilicity of the flavonoid and to dissolve it in SEDDS, enzymatic acylation of rutin with lauric acid was catalyzed by lipase from Candida antarctica in acetone. Different formulations were evaluated regarding their emulsifying properties and ability to dissolve the rutin ester. Suitable SEDDS was chosen and characterized regarding droplet size, polydispersity index, and zeta potential. The rutin fatty ester was loaded into SEDDS to 7% (w/w). Different concentrations of PDMSHEPMS were incorporated in SEDDS for following mucus permeation studies. Formulation with 10% of PDMSHEPMS showed 1.9-fold increase in mucus permeation compared to the formulation without PDMSHEPMS. Furthermore, the formulation with 10% of PDMSHEPMS showed a significant increase in mucus permeation compared with rutin fatty ester without formulation. According to these results, SEDDS containing PDMSHEPMS might be a promising strategy to increase the oral bioavailability of rutin.


Assuntos
Sistemas de Liberação de Medicamentos , Rutina/química , Células CACO-2 , Candida/enzimologia , Sobrevivência Celular/efeitos dos fármacos , Emulsões , Ésteres , Humanos , Lipase/química , Muco/metabolismo , Permeabilidade , Rutina/administração & dosagem
16.
Microb Pathog ; 131: 40-46, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30905714

RESUMO

OBJECTIVE: The aim of the current study was to investigate pathogenic Candida spp. Colonization in oral cavity of postpartum females and its association with adverse pregnancy outcomes (APOs) and dental issues. METHODS: Saliva samples and clinico-demographic data were collected from 267 postpartum females along with 54 non-pregnant females (Jan 2016-March 2018). Isolation of Candida was carried out by using standard microbiological methods and different virulence factors (Esterase activity, phospholipase activity and biofilm formation) were evaluated. RESULTS: Candidacolonization was high in postpartum females (p<0.001, OR = 4.28). This colonization was not significant among females with APOs, however, one to three folds risk was seen with different obstetric and dental factors. High esterase activity was seen among Candida isolates from postpartum females in comparison to control group (p = 0.01). Phospholipase activity of C.albicans isolates from this group was also high (p = 0.001). Majority of the Candida isolates (66.87%) from postpartum females were biofilm formers. Increase in antifungal activity was seen among isolates from postpartum females, with 85% isolates resistant to Fluconazole and Voriconazole (p<0.001) and Amphotericin B resistance was present in 64.38% isolates (p<0.001). CONCLUSION: Postpartum females are more susceptible to oral Candida colonization, which exhibit enhanced virulence characteristics and its carriage are associated with increased risk for development of APOs and dental problems.


Assuntos
Candida/crescimento & desenvolvimento , Candida/isolamento & purificação , Boca/microbiologia , Período Pós-Parto , Adolescente , Adulto , Antifúngicos/farmacologia , Biofilmes/crescimento & desenvolvimento , Candida/enzimologia , Candida/genética , DNA Ribossômico/genética , Farmacorresistência Fúngica/efeitos dos fármacos , Feminino , Humanos , Testes de Sensibilidade Microbiana , Paquistão , Gravidez , Saliva/microbiologia , Fatores de Virulência , Adulto Jovem
17.
Braz J Microbiol ; 50(2): 405-413, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30827000

RESUMO

The effect of gene dosage on the production of Candida antarctica lipase B (CalB) in the methylotrophic yeast Komagataella phaffii, at high densities in a simple medium containing crude glycerin as the sole carbon source, is described. The use of crude glycerin, the main by-product of biodiesel production from vegetable oils, will reduce the production cost of the bioprocess. Two K. phaffii strains were constructed with one or three copies of LipB, an optimized version of the gene encoding CalB under the control of the constitutive PPGK1 promoter. These two constructs were tested and compared on batches using minimal-salts medium with crude glycerin. The strain with three copies achieved a higher enzyme yield (48,760 U/L, 2.3-fold higher than the one-copy strain), with 42 g/L biomass, with no effects on growth.


Assuntos
Candida/enzimologia , Candida/genética , Proteínas Fúngicas/biossíntese , Proteínas Fúngicas/genética , Lipase/biossíntese , Lipase/genética , Pichia/genética , Saccharomycetales/metabolismo , Candida/metabolismo , Dosagem de Genes/genética , Glicerol/metabolismo , Regiões Promotoras Genéticas/genética , Saccharomycetales/genética
18.
Mol Biol Rep ; 46(2): 1797-1808, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30734169

RESUMO

Selenium exhibits health-promoting properties in humans and animals. Therefore, the development of selenium-enriched dietary supplements has been growing worldwide. However, it may also exhibit toxicity at higher concentrations, causing increased oxidative stress. Different species of yeasts may exhibit different tolerances toward selenium. Therefore, in this study, we aimed to determine the effect of selenium on growth and on the antioxidative system in Candida utilis ATCC 9950 and Saccharomyces cerevisiae ATCC MYA-2200 yeast cells. The results of this study have demonstrated that high doses of selenium causes oxidative stress in yeasts, thereby increasing the process of lipid peroxidation. In addition, we obtained an increased level of GSSG from aqueous solutions of yeast biomass grown with selenium supplementation (40-60 mg/L). Increased levels of selenium in aqueous solutions resulted in an increase in the activity of antioxidant enzymes, including glutathione peroxidase and glutathione reductase. These results should encourage future research on the possibility of a thorough understanding of antioxidant system functioning in yeast cells.


Assuntos
Candida/efeitos dos fármacos , Saccharomyces cerevisiae/efeitos dos fármacos , Selênio/metabolismo , Selênio/farmacologia , Antioxidantes/farmacologia , Candida/enzimologia , Candida/metabolismo , Proliferação de Células/efeitos dos fármacos , Suplementos Nutricionais , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Peroxidação de Lipídeos , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/efeitos dos fármacos , Proteínas de Saccharomyces cerevisiae/metabolismo
19.
Int J Biol Macromol ; 130: 333-341, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30797811

RESUMO

Gold nanoparticles decorated graphene oxide (Au-rGO) nanocomposite thin films with enhanced electro-active characteristics were prepared and covalently immobilized with uricase (UOx) enzyme for sensitive and selective detection of uric acid (UA). Differential pulse voltammetry (DPV) studies revealed rapid response of fabricated electrode towards UA at low potential (0.228 V) in a wide concentration range of 50-800 µM with a sensitivity of 86.62 ±â€¯0.19 µA mM-1 and very low detection limit of 7.32 ±â€¯0.21 µM. The obtained Michaelis-Menten constant (km) value of 51.75 µM signifies high enzyme kinetics at electrode surface with UA. The developed biosensor was successfully applied to detect UA in human serum samples. Interferences due to components present in the real matrix were evaluated and UA determination in mixed sample was also performed. The fabricated UOx/Au-rGO/ITO biosensor demonstrated high reproducibility and a shelf-life of 6 months indicating the promising future of Au-rGO nanocomposite as an efficient transducer matrix for biosensing applications. The fast response time (1.0 ±â€¯0.6 s) and improved sensor performance is attributed to the synergistic electronic properties of Au-nanoparticles and rGO that provided enhanced electron transfer and high electro-active species surface coverage at Au-rGO nanocomposite.


Assuntos
Técnicas Biossensoriais/métodos , Enzimas Imobilizadas/química , Ouro/química , Nanopartículas Metálicas/química , Urato Oxidase/química , Ácido Úrico/sangue , Técnicas Biossensoriais/instrumentação , Candida/enzimologia , Eletroquímica , Enzimas Imobilizadas/metabolismo , Grafite/química , Humanos , Limite de Detecção , Modelos Moleculares , Conformação Molecular , Óxidos/química , Fatores de Tempo , Urato Oxidase/metabolismo
20.
J Med Microbiol ; 68(3): 346-354, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30724730

RESUMO

PURPOSE: Non-albicansCandida species have emerged as fungal pathogens that cause invasive infections, with many of these species displaying resistance to commonly used antifungal agents. This study was confined to studying the characteristics of clinical isolates of the C. rugosa complex and C. pararugosa species. METHODOLOGY: Seven isolates of the C. rugosa complex and one isolate of C. pararugosa were obtained from two tertiary referral hospitals in Malaysia. Their antifungal susceptibilities, biofilm, proteinase, phospholipase, esterase and haemolysin activities were characterized. Biofilms were quantified using crystal violet (CV) and tetrazolium (XTT) reduction assays at 1.5, 6, 18, 24, 48 and 72 h.Results/Key findings. The E-test antifungal tests showed that both species have elevated MICs compared to C. albicans and C. tropicalis. The highest biomass was observed in one of the C. rugosa isolates (0.237), followed by C. pararugosa (0.206) at 18 h of incubation. However, the highest bioactivity was observed in the C. rugosa ATCC 10571 strain at 24 h (0.075), followed by C. pararugosa at 48 h (0.048) and the same C. rugosa strain at 24 h (0.046), with P<0.05. All isolates exhibited high proteinase activity (+++) whereas six isolates showed very strong esterase activity (++++). All the isolates were alpha haemolytic producers. None of the isolates exhibited phospholipase activity. CONCLUSION: Elevated MICs were shown for the C. rugosa complex and C. pararugosa for commonly used antifungal drugs. Further studies to identify virulence genes involved in the pathogenesis and genes that confer reduced drug susceptibility in these species are proposed.


Assuntos
Biofilmes , Candida/efeitos dos fármacos , Peptídeo Hidrolases/metabolismo , Fosfolipases/metabolismo , Antifúngicos/farmacologia , Candida/enzimologia , Candida/isolamento & purificação , Candidemia , Candidíase , Hospitais de Ensino , Humanos , Malásia , Testes de Sensibilidade Microbiana , Pele/microbiologia , Centros de Atenção Terciária
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA