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1.
Food Microbiol ; 119: 104429, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38225038

RESUMO

Previous metagenomic analyses have suggested that lactobacilli present potential for Quorum Sensing (QS) in cocoa fermentation, and in the present research, laboratory scale fermentations were carried out to monitor the expression of luxS, a universal marker of QS. For that, 96 h-fermentations were studied, as follows: F0 (non inoculated control), F1 (inoculated with yeasts, lactic acid bacteria, and acetic acid bacteria), F2 (inoculated with yeasts and acetic acid bacteria), F3 (inoculated with yeasts only). The parameters evaluated were: plate counting, quantification of key enzymes and analysis of volatile organic compounds associated with key sensory descriptors, using headspace gas chromatography-mass spectrometry (GC-MS). Furthermore, QS was estimated by the quantification of the expression of luxS genes by Reverse Transcriptase Real-Time PCR. The results demonstrated that microbial succession occurred in pilot scale fermentations, but no statistical differences for microbial enumeration and α-diversity index were observed among experiments and control. Moreover, it was not possible to make conclusive correlations of enzymatic profile and fermenting microbiota, likely due to the intrinsic activity of plant hydrolases. Regarding to the expression of luxS genes, in Lactiplantibacillus plantarum they were active along the fermentation, but for Limosilactobacillus fermentum, luxS was expressed only at early and middle phases. Correlation analysis of luxS expression and production of volatile metabolites evidenced a possible negative association of Lp. Plantarum with fermentation quality. In conclusion, these data corroborate former shotgun metagenomic analysis by demonstrating the expression of luxS by lactobacilli in pilot scale cocoa fermentation and evidence Lp. Plantarum is the main lactic acid bacteria related to its expression.


Assuntos
Cacau , Chocolate , Fermentação , Lactobacillus/genética , Lactobacillus/metabolismo , Cacau/microbiologia , Ácido Acético/metabolismo , Expressão Gênica
2.
J Appl Microbiol ; 130(3): 865-877, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32741059

RESUMO

AIMS: Optimization of ß-galactosidase production by Trichoderma sp. under solid-state fermentation using wheat bran as solid substrate through an experimental design and its application targeting the recovery of galactooligosaccharides (GOS) from whey cheese. METHODS AND RESULTS: The ß-galactosidase production by Trichoderma sp. increased 2·3-fold (2·67 U g-1 of substrate) culturing the fungus at 30°C for 187 h, at an inoculum of 105 spores per ml, and a 1 : 1·65 (w/v) ratio of wheat bran to tap water. The best enzyme activity was obtained at 55°C and pH 4·5. The catalytic activity was maintained for up to 180 min incubating at 35-45°C, and above 50% at acidic or alkaline pH for up to 24 h. It also presented resistance to chemical compounds. ß-galactosidase catalysed the hydrolysis of the lactose and the transgalactosylation reaction leading to the production of GOS. CONCLUSION: Trichoderma sp. produced ß-galactosidase with transgalactosylation activity that may be used to recover GOS, products with high added value, from whey cheese. SIGNIFICANCE AND IMPACT OF THE STUDY: ß-galactosidases are used in different industrial sectors. Therefore, the Trichoderma ß-galactosidase is a promising alternative for the production of GOS as prebiotic from the dairy effluents, contributing to the reduction in the environmental impact.


Assuntos
Galactose/metabolismo , Oligossacarídeos/metabolismo , Trichoderma/metabolismo , Soro do Leite/metabolismo , beta-Galactosidase/metabolismo , Queijo , Fibras na Dieta/metabolismo , Fermentação , Glicosilação , Hidrólise , Lactose/metabolismo , Prebióticos , Soro do Leite/química
3.
Clin Exp Immunol ; 185(2): 202-9, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27059407

RESUMO

A high number of Leishmania-responder T cells is found in cutaneous leishmaniasis lesions, suggesting that important immunological events occur at the site of infection. Although activated, cytotoxic and regulatory T cells infiltrating into lesions may influence disease pathogenesis, the role of the T cell differentiation pattern of lymphocytes in lesions is unknown. Our aim was to investigate whether the phase of lesion development (early or late) is influenced by the functional status of cells present in inflammatory infiltrate. Activation, cytotoxity and T cell differentiation molecules were evaluated in lesion mononuclear cells by flow cytometry. The frequency of T cells was correlated with the lesion area (r = 0·68; P = 0·020). CD4(+) CD25(+) T cells predominated over CD4(+) CD69(+) T cells in early lesions (less than 30 days), whereas late lesions (more than 60 days) exhibited more CD4(+) CD69(+) T cells than CD4(+) CD25(+) T cells. The duration of illness was correlated positively with CD4(+) CD69(+) (r = 0·68; P = 0·005) and negatively with CD4(+) CD25(+) T cells (r = -0·45; P = 0·046). Most CD8(+) T cells expressed cytotoxic-associated molecules (CD244(+) ), and the percentages were correlated with the lesion area (r = 0·52; P = 0·04). Both CD4(+) and CD8(+) effector memory T cells (TEM -CD45RO(+) CCR7(-) ) predominated in CL lesions and were significantly higher than central memory (TCM -CD45RO(+) CCR7(+) ) or naive T cells (CD45RO(-) CCR7(+) ). An enrichment of TEM cells and contraction of naive T cells were observed in lesions in comparison to blood (P = 0·006) for both CD4(+) and CD8(+) T cells. Lesion chronicity is associated with a shift in activation phenotype. The enrichment of TEM and activated cytotoxic cells can contribute to immune-mediated tissue damage.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Memória Imunológica , Leishmaniose Cutânea/imunologia , Pele/imunologia , Subpopulações de Linfócitos T/imunologia , Adolescente , Adulto , Idoso , Feminino , Citometria de Fluxo , Humanos , Leishmania/imunologia , Leishmaniose Cutânea/fisiopatologia , Antígenos Comuns de Leucócito/imunologia , Ativação Linfocitária , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Fenótipo , Pele/citologia , Pele/parasitologia , Linfócitos T Reguladores/imunologia , Fatores de Tempo , Adulto Jovem
4.
Anim Reprod Sci ; 143(1-4): 19-23, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24287150

RESUMO

The present study evaluated the use of sex-sorted sperm upon estrus detection (ED) or following timed artificial insemination (TAI) in lactating dairy cows. Additionally, the effect of the presence of a corpus luteum (CL) at the beginning of the TAI protocol was verified. Cows (539 crossbred Gir × Holstein and 87 Holstein) were classified according to the presence or absence of CL by ultrasonography exam. Cows with a CL were randomly assigned into one of two groups (CL-ED/AI or CL-TAI), and cows without a CL (NoCL-TAI) received TAI. Cows from the CL-ED/AI group received 500mg of cloprostenol intramuscularly and were inseminated 12h after ED in the following five days. Cows from the TAI groups (CL or NoCL) received TAI. Cows receiving CL-ED/AI had a lower (P<0.0001) service rate (45.1%, 101/224) than TAI groups (CL-TAI=94.2%, 180/191 and NoCL-TAI=97.2%, 205/211). However, cows receiving AI upon ED (CL-ED/AI=31.7%, 32/101) presented higher (P=0.03) pregnancy per AI (P/AI) than cows bred following TAI (CL-TAI=19.4%, 35/180 and NoCL-TAI=23.9%, 49/205). Despite the lower P/AI, cows receiving TAI presented greater (P=0.07) proportion of pregnant cows at the end of the reproductive program (CL-TAI=18.3%, 35/191 and NoCL-TAI=23.2%, 49/211) than those inseminated upon ED (14.3%, 32/224). There was no effect (P=0.45) of the presence of a CL at the beginning of the synchronization protocol on P/AI. Thus, the use of TAI programs, regardless of the presence of CL in the beginning of the synchronization protocol, increases the service and pregnancy rates but reduces the P/AI when compared to the use of sex-sorted sperm upon ED.


Assuntos
Detecção do Estro , Inseminação Artificial/veterinária , Pré-Seleção do Sexo/veterinária , Espermatozoides/citologia , Animais , Bovinos , Indústria de Laticínios , Sincronização do Estro , Feminino , Lactação , Masculino , Gravidez , Taxa de Gravidez , Pré-Seleção do Sexo/métodos
5.
Parasite Immunol ; 35(2): 65-72, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23050581

RESUMO

Leishmaniasis is an important tropical disease composed of several clinical forms that adversely affect millions of people globally. Critical cells involved in the host-Leishmania interaction are monocytes and macrophages, which act to protect against infections due to their ability to both control intracellular infections and regulate the subsequent adaptive immune response. Both soluble factors and cell surface receptors are keys in directing the immune response following interaction with pathogens such as Leishmania. Toll-like receptors (TLRs) have an essential role in immune responses against infections, but little is known about their role in human infection with Leishmania braziliensis. In this work, we evaluated peripheral blood CD14+ monocytes for the expression of immunoregulatory cytokines, co-stimulatory molecules and TLR9 from cutaneous leishmaniasis patients infected with L. braziliensis and noninfected individuals. Our results showed that patients present decreased expression of co-stimulatory molecules such as CD80 and CD86 following culture with media alone or after stimulus with soluble Leishmania antigen. Interestingly, TLR9 expression was higher after culture with soluble Leishmania antigen (SLA), suggesting a role of this molecule in immunoregulation of active disease. Lastly, higher frequencies of TLR9+ monocytes were correlated with greater lesion size. These findings demonstrate a peripheral monocytes profile compatible with important immunoregulatory potential.


Assuntos
Leishmania braziliensis/imunologia , Leishmaniose Cutânea/imunologia , Leucócitos Mononucleares/imunologia , Monócitos/imunologia , Receptor Toll-Like 9/imunologia , Imunidade Adaptativa/imunologia , Adolescente , Adulto , Antígenos de Protozoários/imunologia , Antígeno B7-1/sangue , Antígeno B7-2/sangue , Antígenos CD40/sangue , Citocinas/sangue , Citometria de Fluxo , Humanos , Leishmaniose Cutânea/sangue , Leishmaniose Cutânea/parasitologia , Leishmaniose Cutânea/patologia , Leucócitos Mononucleares/patologia , Pessoa de Meia-Idade , Monócitos/parasitologia , Receptor Toll-Like 9/sangue , Adulto Jovem
6.
Clin Exp Immunol ; 165(3): 338-51, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21726211

RESUMO

Leishmaniasis is caused by infection with the protozoan parasite, Leishmania, that parasitizes human cells, and the cellular immune response is essential for controlling infection. In order to measure the host T cell response to Leishmania infection, we have measured the expansion, activation state and functional potential of specific T cells as identified by their T cell receptor Vß region expression. In a group of cutaneous leishmaniasis (CL) patients, we evaluated these characteristics in nine different T cell subpopulations as identified by their Vß region expression, before and after specific Leishmania antigen stimulation. Our results show: (1) an increase in CD4(+) T cells expressing Vß 5·2 and Vß 24 in CL compared to controls; (2) a Leishmania antigen-induced increase in CD4(+) T cells expressing Vß 5·2, 11, 12 and 17; (3) a profile of previous activation of CD4(+) Vß 5·2-, 11- and 24-positive T cells, with higher expression of CD45RO, HLA-DR, interferon-γ, tumour necrosis factor-α and interleukin-10 compared to other Vß-expressing subpopulations; (4) a positive correlation between higher frequencies of CD4(+) Vß5·2(+) T cells and larger lesions; and (5) biased homing of CD4(+) T cells expressing Vß 5·2 to the lesion site. Given that CL disease involves a level of pathology (ulcerated lesions) and is often followed by long-lived protection and cure, the identification of specific subpopulations active in this form of disease could allow for the discovery of immunodominant Leishmania antigens important for triggering efficient host responses against the parasite, or identify cell populations most involved in pathology.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Leishmania braziliensis/imunologia , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/patologia , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Subpopulações de Linfócitos T/imunologia , Adolescente , Adulto , Antígenos de Protozoários/imunologia , Contagem de Linfócito CD4 , Linfócitos T CD4-Positivos/patologia , Movimento Celular/imunologia , Citocinas/metabolismo , Feminino , Antígenos HLA-DR/metabolismo , Humanos , Interferon gama/metabolismo , Interleucina-10/metabolismo , Leishmania braziliensis/isolamento & purificação , Leishmaniose Cutânea/diagnóstico , Antígenos Comuns de Leucócito/metabolismo , Leucócitos Mononucleares/imunologia , Ativação Linfocitária/imunologia , Masculino , Pessoa de Meia-Idade , Pele/imunologia , Pele/patologia , Subpopulações de Linfócitos T/metabolismo , Subpopulações de Linfócitos T/patologia , Fator de Necrose Tumoral alfa/metabolismo , Adulto Jovem
7.
Genes Immun ; 12(7): 589-94, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21633373

RESUMO

Mapping murine genes controlling cutaneous leishmaniasis (CL) identified Fli1 as a candidate influencing resistance to L. major and enhanced wound healing. We examine FLI1 as a gene controlling CL and mucosal leishmaniasis (ML) caused by L. braziliensis in humans. Intron 1 single nucleotide polymorphisms tagging promoter and enhancer elements were analysed in 168 nuclear families (250 CL; 87 ML cases) and replicated in 157 families (402 CL; 39 ML cases). Robust case-pseudocontrol logistic regression analysis showed association between allele C (odds ratio (OR) 1.65; 95% confidence interval 1.18-2.29; P=0.003) of FLI1_rs7930515 and CL in the primary sample that was confirmed (OR 1.60; 95% confidence interval 1.10-2.33; P=0.014) in the replication set (combined P=1.8 × 10(-4)). FLI1_rs7930515 is in linkage disequilibrium with the functional GAn microsatellite in the proximal promoter. Haplotype associations extended across the enhancer, which was not polymorphic. ML associated with inverse haplotypes compared with CL. Wound healing is therefore important in CL, providing potential for therapies modulating FLI1.


Assuntos
Predisposição Genética para Doença , Leishmaniose Cutânea/genética , Polimorfismo de Nucleotídeo Único , Proteína Proto-Oncogênica c-fli-1/genética , Alelos , Brasil , Frequência do Gene , Haplótipos , Humanos , Íntrons , Grupos Raciais/genética
8.
Trans R Soc Trop Med Hyg ; 103(7): 712-5, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19481233

RESUMO

American tegumentary leishmaniasis (ATL) can occur in different forms, classically categorised as cutaneous leishmaniasis, mucosal leishmaniasis, diffuse cutaneous leishmaniasis and disseminated leishmaniasis. We analysed the presence of atypical manifestations (vegetative, verrucous, crusted and lupoid) among a cohort of patients presenting to the Health Post of Corte de Pedra, Bahia, Brazil. Among 1396 patients diagnosed with ATL in 2005-2006, 35 patients (2.5%) presented with atypical manifestations of the disease. Of these patients, 14 were pregnant women, 2 were co-infected with HIV and 19 had no co-morbidity or other apparent risk factors for the development of atypical ATL. The latter 19 patients were the focus of this study. They were predominantly adult males, frequently presenting with facial lesions [P<0.001; odds ratio (OR)=17.5, 95% CI 6.1-52.4] and had higher rates of treatment failure with antimonial therapy (P<0.001; OR=327, 95% CI 45-6668) compared with patients with classic ATL attending in the same period. Thirteen cases healed with amphotericin B, introduced after failure of three or more courses of antimony, suggesting that amphotericin B should be considered as the drug of choice for all patients diagnosed with atypical ATL.


Assuntos
Leishmania braziliensis , Leishmaniose Cutânea/patologia , Adolescente , Adulto , Anfotericina B/uso terapêutico , Animais , Antiprotozoários/uso terapêutico , Brasil/epidemiologia , Dermatoses Faciais/parasitologia , Dermatoses Faciais/patologia , Feminino , Humanos , Leishmania braziliensis/efeitos dos fármacos , Leishmania braziliensis/imunologia , Leishmaniose Cutânea/tratamento farmacológico , Leishmaniose Cutânea/imunologia , Masculino , Meglumina/uso terapêutico , Antimoniato de Meglumina , Pessoa de Meia-Idade , Compostos Organometálicos/uso terapêutico , Gravidez , Complicações Parasitárias na Gravidez/patologia , Prognóstico , Medição de Risco , Fatores de Risco , Resultado do Tratamento , Adulto Jovem
9.
Braz. j. microbiol ; 39(2): 344-352, Apr.-June 2008. ilus, graf, tab
Artigo em Inglês | LILACS | ID: lil-487716

RESUMO

Two strains (15.1 and 15.8) of the thermophilic fungus Scytalidium thermophilum produced high levels of intracellular glucoamylases, with potential for industrial applications. The isoform I of the glucoamylase produced by 15.1 strain was sequentially submitted to DEAE-Cellulose and CM-Cellulose chromatography, and purified 141-fold, with 5.45 percent recovery. The glucoamylase of strain 15.8 was purified 71-fold by CM-Cellulose and Concanavalin A-Sepharose chromatography, with 7.38 percent recovery. Temperature and pH optima were in the range of 50-60ºC and 5.0-6.0, respectively, using starch and maltose as substrates. The glucoamylase of S. thermophilum 15.8 was more stable (t50 > 60 min) than that of S. thermophilum 15.1 (t50= 11-15 min), at 60ºC. The glucoamylase activities were enhanced by several ions (e.g. Mn2+ and Ca2+) and inhibited by β-mercaptoethanol. The glucoamylase from 15.1 strain showed a Km of 0.094 mg/ml and 0.029 mg/ml and Vmax of 202 U/mg prot and 109 U/mg prot, for starch and maltose, respectively. The hydrolysis products of starch and maltose, analyzed by TLC, demonstrated glucose as end product and confirming the character of the enzyme as glucoamylase. Differences were observed in relation to the products formed with maltose as substrate between the two strains studied. S. thermophilum 15.8 formed maltotriose in contrast with S. thermophilum 15.1.


Duas linhagens (15.1 e 15.8) do fungo termofílico Scytalidium thermophilum se mostraram produtoras de grandes quantidades de glucoamilases, com potencial aplicação industrial. A isoforma I de glucoamilase produzida pela linhagem 15.1 foi submetida seqüencialmente a cromatografia em colunas de DEAE-celulose e CM-celulose, sendo purificada 141 vezes com porcentagem de recuperação de 5,45 por cento. A glucoamilase da linhagem 15.8 foi purificada 71 vezes através do uso de colunas de cromatografia de CM-celulose e Concanavalina A-sepharose com porcentagem de recuperação de 7,38 por cento. Temperatura e pH ótimo foram de 50-60ºC e 5,0-6,0 respectivamente, utilizando-se amido e maltose como substratos. A glucoamilase de S. thermophilum 15.8 se mostrou mais estável (t50 > 60 min) que a de S. thermophilum 15.1 (t50 =11-15min) a 60ºC. As glucoamilases tiveram suas atividades enzimáticas aumentadas na presença de vários íons (ex: Mn2+, e Ca2+) e inibidas por β-mercaptoetanol. A glucoamilase da linhagem 15.1 apresentou um Km de 0,094 mg/ml e 0,029 mg/ml and Vmax de 202U/mg prot e 109U/mg prot, para amido e maltose respectivamente. A análise do produto da hidrólise de amido e maltose por TLC, demonstrou que o produto final era glucose, confirmando as características da enzima como glucoamilase. Diferenças entre as duas linhagens foram observadas com relação aos produtos formados tendo maltose como susbstrato, a linhagem 15.8 de S. thermophilum produziu maltotriose como produto final em contrate com a linhagem 15.1.


Assuntos
Ensaios Enzimáticos Clínicos , Enzimas/análise , Fungos , /análise , Técnicas In Vitro , Microbiologia Industrial , Cromatografia , Meios de Cultura , Hidrólise , Métodos
10.
Folia Microbiol (Praha) ; 53(6): 509-16, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19381476

RESUMO

The biochemical properties of the alkaline phosphatases (AlPs) produced by Rhizopus microsporus are described. High enzymic levels were produced within 1-2 d in agitated cultures with 1 % wheat bran. Intra- and extracellular AlPs were purified 5.0 and 9.3x, respectively, by DEAE-cellulose and ConA-sepharose chromatography. Molar mass of 118 and 120 kDa was estimated by gel filtration for both forms of phosphatases. SDS-PAGE indicated dimeric structures of 57 kDa for both forms. Mn(2+), Na(+) and Mg(2+) stimulated the activity, while Al(3+) and Zn(2+) activated only the extracellular form. Optimum temperature and pH for both phosphatases were 65 degrees C and pH 8.0, respectively. The enzymes were stable at 50 degrees C for at least 15 min. Hydrolysis of 4-nitrophenyl phosphate exhibited a K (m) 0.28 and 0.22 mmol/L, with upsilon (lim) 5.89 and 4.84 U/mg, for intra- and extracellular phosphatases, respectively. The properties of the reported AlPs may be suitable for biotechnological application.


Assuntos
Fosfatase Alcalina/isolamento & purificação , Proteínas Fúngicas/isolamento & purificação , Rhizopus/enzimologia , Fosfatase Alcalina/metabolismo , Cátions/farmacologia , Cromatografia em Agarose , Cromatografia DEAE-Celulose , Cromatografia em Gel , Eletroforese em Gel de Poliacrilamida , Proteínas Fúngicas/metabolismo , Temperatura Alta , Concentração de Íons de Hidrogênio , Peso Molecular
11.
Braz J Microbiol ; 39(2): 344-52, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24031228

RESUMO

Two strains (15.1 and 15.8) of the thermophilic fungus Scytalidium thermophilum produced high levels of intracellular glucoamylases, with potential for industrial applications. The isoform I of the glucoamylase produced by 15.1 strain was sequentially submitted to DEAE-Cellulose and CM-Cellulose chromatography, and purified 141-fold, with 5.45% recovery. The glucoamylase of strain 15.8 was purified 71-fold by CM- Cellulose and Concanavalin A-Sepharose chromatography, with 7.38% recovery. Temperature and pH optima were in the range of 50-60°C and 5.0-6.0, respectively, using starch and maltose as substrates. The glucoamylase of S. thermophilum 15.8 was more stable (t50 > 60 min) than that of S. thermophilum 15.1 (t50= 11-15 min), at 60°C. The glucoamylase activities were enhanced by several ions (e.g. Mn(2+) and Ca(2+)) and inhibited by ß- mercaptoethanol. The glucoamylase from 15.1 strain showed a Km of 0.094 mg/ml and 0.029 mg/ml and Vmax of 202 U/mg prot and 109 U/mg prot, for starch and maltose, respectively. The hydrolysis products of starch and maltose, analyzed by TLC, demonstrated glucose as end product and confirming the character of the enzyme as glucoamylase. Differences were observed in relation to the products formed with maltose as substrate between the two strains studied. S. thermophilum 15.8 formed maltotriose in contrast with S. thermophilum 15.1.

12.
Bioprocess Biosyst Eng ; 31(4): 329-34, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17940804

RESUMO

Rhizopus microsporus var. rhizopodiformis produced high levels of alpha-amylase and glucoamylase under solid state fermentation, with several agricultural residues, such as wheat bran, cassava flour, sugar cane bagasse, rice straw, corncob and crushed corncob as carbon sources. These materials were humidified with distilled water, tap water, or saline solutions--Segato Rizzatti (SR), Khanna or Vogel. The best substrate for amylase production was wheat bran with SR saline solution (1:2 v/v). Amylolytic activity was still improved (14.3%) with a mixture of wheat bran, corncob, starch and SR saline solution (1:1:0.3:4.6 w/w/w/v). The optimized culture conditions were initial pH 5, at 45 degrees C during 6 days and relative humidity around 76%. The crude extract exhibited temperature and pH optima around 65 degrees C and 4-5, respectively. Amylase activity was fully stable for 1 h at temperatures up to 75 degrees C, and at pH values between 2.5 and 7.5.


Assuntos
Amilases/química , Amilases/metabolismo , Reatores Biológicos/microbiologia , Técnicas de Cultura de Células/métodos , Fibras na Dieta/microbiologia , Triticum/microbiologia , Zea mays/microbiologia , Ativação Enzimática , Estabilidade Enzimática , Especificidade da Espécie
13.
Folia Microbiol (Praha) ; 52(3): 231-6, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17702460

RESUMO

Biochemical properties of a termostable alkaline phosphatase obtained from the mycelium extract of A. caespitosus were described. The enzyme was purified 42-fold with 32% recovery by DEAE-cellulose and concanavalin A-Sepharose chromatography. The molar mass estimated by Sephacryl S-200 or by 7% SDS-PAGE was 138 kDa and 71 kDa, respectively, indicating a homodimer. Temperature and pH optima were 80 degrees C and pH 9.0. This enzyme was highly glycosylated (approximately 74% saccharide content). The activity was enhanced by Mg2+ (19-139%), NH4+ (64%), Na+ (51%) and Mn2+ (38%). 4-Nitrophenyl phosphate (4-NPP) was preferentially hydrolyzed, but glucose 1-phosphate (93%), UTP (67%) and O-phosphoamino acids also acted as substrates. V(lim) and K(m) were 3.78 nkat per mg protein and 270 micromol/L in the absence of Mg2+ and 7.35 nkat per mg protein and 410 micromol/L in the presence of Mg2+, using 4-NPP as substrate. The purified alkaline phosphatase removed the 5'-phosphate group of a linearized plasmid without showing DNAase activity, indicating its potential for recombinant DNA technology.


Assuntos
Fosfatase Alcalina/isolamento & purificação , Fosfatase Alcalina/metabolismo , Aspergillus/enzimologia , Micélio/enzimologia , Fosfatase Alcalina/química , Desoxirribonucleases/metabolismo , Cinética , Especificidade por Substrato
14.
Scand J Immunol ; 63(1): 70-8, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16398703

RESUMO

Leishmania braziliensis is a parasite that can induce at least two clinical forms of leishmaniasis in humans: cutaneous leishmaniasis (CL) and mucosal leishmaniasis (ML). In humans, the specific mechanisms that determine which form will develop following infection are not well established. In this study, peripheral blood mononuclear cells from 17 CL and 9 ml patients were compared both ex vivo and after culture with soluble leishmania antigen (SLA). Patients with ML presented a higher frequency of activated T cells as measured by ex vivo frequencies of (CD4+)(CD69+), (CD4+)(CD28-), (CD4+)(CD62L-) and (CD8+)(CD69+) than those with CL. Moreover, after stimulation with SLA, patients with ML presented a higher frequency of TNF-alpha-producing CD4+ and CD14+ cells than CL individuals. While CL patients displayed a positive correlation between the frequency of IL-10 and TNF-alpha-producing monocytes, the ML patients did not. This lack of a positive correlation between IL-10-producing and TNF-alpha-producing monocytes in ML patients could lead to a less controlled inflammatory response in vivo. These results corroborate with a model of an exacerbated, unregulated, immune response in ML patients and point to key immunomodulatory leucocyte populations and cytokine networks that may be involved in the development of immunopathology in ML patients.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Leishmaniose Mucocutânea/imunologia , Monócitos/imunologia , Antígenos CD/análise , Humanos , Interleucina-10/metabolismo , Leishmaniose Tegumentar Difusa/imunologia , Ativação Linfocitária , Fator de Necrose Tumoral alfa/metabolismo
15.
Infect Immun ; 72(1): 508-14, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14688132

RESUMO

In Corte de Pedra (CP), northeastern Brazil, Leishmania braziliensis causes three distinct forms of American tegumentary leishmaniasis (ATL). To test the hypothesis that strain polymorphism may be involved in this disease spectrum and accurately characterize the parasite population structure in CP, we compared one L. major, two non-CP L. braziliensis, one CP L. amazonensis, and 45 CP L. braziliensis isolates, obtained over a 10-year period from localized cutaneous, mucosal, and disseminated leishmaniasis patients, with randomly amplified polymorphic DNA (RAPD). Electrophoretic profiles were mostly unique across species. All typing protocols revealed polymorphism among the 45 CP L. braziliensis isolates, which displayed eight different RAPD patterns and greater than 80% overall fingerprint identity, attesting to the adequacy of the tools to assess strain variability in CP's geographically limited population of parasites. The dendrogram based on the sum of RAPD profiles of each isolate unveiled nine discrete typing units clustered into five clades. Global positioning showed extensive overlap of these clades in CP, precluding geographic sequestration as the mechanism of the observed structuralization. Finally, all forms of ATL presented a statistically significant difference in their frequencies among the clades, suggesting that L. braziliensis genotypes may be accompanied by specific disease manifestation after infection.


Assuntos
Doenças Endêmicas , Leishmania braziliensis/classificação , Leishmaniose Cutânea/epidemiologia , Leishmaniose Cutânea/fisiopatologia , Polimorfismo Genético , Animais , Brasil/epidemiologia , DNA de Protozoário/análise , Genótipo , Humanos , Leishmania braziliensis/genética , Leishmaniose Cutânea/parasitologia , Técnica de Amplificação ao Acaso de DNA Polimórfico
16.
Folia Microbiol (Praha) ; 48(5): 627-32, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14976719

RESUMO

Among 30 species of filamentous fungi isolated from Brazilian soil, Aspergillus caespitosus produced and secreted the highest levels of alkaline phosphatase in culture medium supplemented with xylan. The extracellular alkaline phosphatase was purified by DEAE-cellulose and concanavalin A-sepharose chromatography. The enzyme was a glycoprotein containing up to 56% sugar with molar mass of 134.8 kDa, according to gel filtration in Sepharose CL-6B, and 57 kDa according to SDS-PAGE. Nondenaturing electrophoresis (6% PAGE) of the purified enzyme produced a single band, suggesting that the native enzyme was a homodimer. Optima of temperature and pH were 75 degrees C and 8.5, respectively. The enzyme was stable at 50 degrees C and its activity was enhanced by 95% in the presence of Mg2+ (1 mmol/L). 4-Nitrophenyl phosphate was the preferentially hydrolyzed substrate with K(m) and upsilon lim values of 74 mumol/L and 285 mumol/s, in the absence, and 90 mumol/L and 418 mumol/s, in the presence of Mg2+, respectively. The enzyme also hydrolyzed other phosphorylated amino acids (O-phosphothreonine, O-phosphotyrosine, O-phosphoserine).


Assuntos
Fosfatase Alcalina/metabolismo , Aspergillus/enzimologia , Fosfatase Alcalina/química , Fosfatase Alcalina/isolamento & purificação , Carboidratos , Inibidores Enzimáticos/farmacologia , Glicoproteínas/química , Glicoproteínas/isolamento & purificação , Glicoproteínas/metabolismo , Concentração de Íons de Hidrogênio , Cinética , Peso Molecular , Especificidade por Substrato , Temperatura
17.
J Ind Microbiol Biotechnol ; 27(4): 265-70, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11687941

RESUMO

An extracellular (conidial) and an intracellular (mycelial) alkaline phosphatase from the thermophilic fungus Scytalidium thermophilum were purified by DEAE-cellulose and Concanavalin A-Sepharose chromatography. These enzymes showed allosteric behavior either in the presence or absence of MgCl(2), BaCl(2), CuCl(2), and ZnCl(2). All of these ions increased the maximal velocity of both enzymes. The molecular masses of the conidial and mycelial enzymes, estimated by gel filtration, were 162 and 132 kDa, respectively. Both proteins migrated on SDS-PAGE as a single polypeptide of 63 and 58.5 kDa, respectively, suggesting that these enzymes were dimers of identical subunits. The best substrate for the conidial and mycelial phosphatases was p-nitrophenylphosphate, but beta-glycerophosphate and other phosphorylated compounds also served as substrates. The optimum pH for the conidial and mycelial alkaline phosphatases was 10.0 and 9.5 in the presence of AMPOL buffer, and their carbohydrate contents were about 54% and 63%, respectively. The optimum temperature was 70-75 degrees C for both activities. The enzymes were fully stable up to 1 h at 60 degrees C. These and other properties suggested that the alkaline phosphatases of S. thermophilum might be suitable for biotechnological applications.


Assuntos
Fosfatase Alcalina , Fungos/enzimologia , Temperatura Alta , Fosfatase Alcalina/química , Fosfatase Alcalina/isolamento & purificação , Fosfatase Alcalina/metabolismo , Biotecnologia/métodos , Meios de Cultura , Estabilidade Enzimática , Fungos/fisiologia , Especificidade por Substrato
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