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1.
Electron. j. biotechnol ; 44: 1-5, Mar. 2020. graf, tab
Artigo em Inglês | LILACS | ID: biblio-1087706

RESUMO

Background: Freeze-drying is known as one of the best methods to preserve bacterial strains. Protectant is the key factor affecting the survival rate of freeze-dried strains. In addition, salinity, bacterial suspension concentration, drying time, and other factors can also affect the survival rate of strains to varying degrees. At present, there are relatively few studies on freeze-drying preservation of marine bacteria. In the present study, we performed the freeze-drying protectant screening and optimized the preservation conditions for Pseudoalteromonas nigrifaciens, which is widely distributed in marine environment. The protective effects of the screened protectants were verified by 18 other marine bacterial strains. Results: The results indicated that the combination of 5.0% (w/v) lactose, 5.0% (w/v) mannitol, 5.0% (w/v) trehalose, 10.0% (w/v) skim milk powder, 0.5% (w/v) ascorbic acid and 0.5% (w/v) gelatin was the best choice for the preservation of P. nigrifaciens. The suggested salinity and concentration of initial cell suspension were 10 g/L NaCl and 1.0 × 109 CFU/mL, respectively. Furthermore, stationary-phase cells were the best choice for the freeze-drying process. The highest survival rate of P. nigrifaciens reached 52.8% when using 5­10% (w/v) skim milk as rehydration medium. Moreover, the other 18 marine strains belonging to Pseudoalteromonas, Vibrio, Photobacterium, Planomicrobium, Edwardsiella, Enterococcus, Bacillus, and Saccharomyces were freezedried under the abovementioned conditions. Their survival rates were 2.3­95.1%. Conclusion: Collectively, our results supported that the protectant mixture and parameters were beneficial for lyophilization of marine bacteria


Assuntos
Preservação Biológica/métodos , Pseudoalteromonas/fisiologia , Liofilização/métodos , Trealose/química , Sobrevivência Celular , Fenômenos Fisiológicos Bacterianos , Dissacarídeos/química , Viabilidade Microbiana , Salinidade , Lactose/química , Manitol/química
2.
Mem. Inst. Oswaldo Cruz ; 115: e200401, 2020. graf
Artigo em Inglês | LILACS, Sec. Est. Saúde SP | ID: biblio-1135257

RESUMO

BACKGROUND Candida glabrata yeast is the second cause of candidiasis worldwide. Differs from other yeasts since assimilates only glucose and trehalose (a characteristic used in rapid identification tests for this pathogen) by secreting into the medium a highly active acid trehalase encoded by the CgATH1 gene. OBJECTIVE This study aimed to characterise the function of the acid trehalase in the physiopathology of C. glabrata. METHODS Gene deletion was performed to obtain a mutant ath1Δ strain, and the ability of the ath1Δ strain to grow in trehalase, or the presence of trehalase activity in the ath1Δ yeast cells, was verified. We also tested the virulence of the ath1Δ strain in a murine model of infection. FINDINGS The ath1Δ mutant strain grows normally in the presence of glucose, but loses its ability to grow in trehalose. Due to the high acid trehalase activity present in wild-type cells, the cytoplasmic neutral trehalase activity is only detected in the ath1Δ strain. We also observed a significantly lower virulence of the ath1Δ strain in a murine model of infection with either normal or immunocompromised mice. MAIN CONCLUSIONS The acid trehalase is involved in the hydrolysis of external trehalose by C. glabrata, and the enzyme also plays a major virulence role during infectivity.


Assuntos
Animais , Camundongos , Trealase/metabolismo , Virulência/genética , Candida glabrata/genética , Trealase/fisiologia , Trealase/genética , Trealose/análise , Virulência/fisiologia , Candidíase , Deleção de Genes , Candida glabrata/fisiologia , Candida glabrata/metabolismo , Candida glabrata/patogenicidade , Genes Fúngicos , Hidrolases
3.
São Paulo; s.n; s.n; 2020. 81 p. tab, graf.
Tese em Português | LILACS | ID: biblio-1290784

RESUMO

Muitos pacientes acometidos por infecções fúngicas sucumbem devido a não eficácia dos antibióticos ou por toxicidade dos mesmos. Anfotericina B é um dos antifúngicos mais eficientes do mercado apesar de sua alta toxicidade, tem estrutura poliênica e é um composto insolúvel em água, sendo necessário o uso de adjuvantes e novas tecnologias para preparo de formulações eficazes. Cetoconazol é um composto imidazólico, também com ação antifúngica de grande espectro de ação e difícil solubilização em meio aquouso, porém solúvel somente em baixos valores de pH. Estudos têm demonstrado a utilização de bixina na preparação de dispersões aquosas de compostos insolúveis ou pouco solúveis em água. Bixina é o principal composto das cascas de semente de Bixa orellana (urucum), sendo um carotenoide insolúvel em água, porém, permite preparações na forma de nanodispersões aquosas com incorporação de fármacos apolares ou lipofílicos. O objetivo deste trabalho foi preparar anfotericina B e cetoconazol na forma de nanodispersões a partir de bixina, utilizando pullulan e trealose como adjuvantes e avaliar estabilidade e eficácia antimicrobiana por ensaios físico-químicos e microbiológicos. Pullulan é um polissacarídeo constituído por unidades de maltotriose, com propriedades adesivas e capacidade de formar biofilmes, enquanto trealose é um composto com duas unidades de glicose, com boa estabilidade em faixas de pH de 3 a 10 e capaz de suportar altas temperaturas, como processos de esterilização por calor úmido. Ensaios físico-químicos demonstraram boa manutenção das características das preparações propostas neste projeto, como, por exemplo, diâmetro hidrodinâmico e potencial zeta das estruturas das nanodispersões de bixina e antifúngicos e também eficácia antimicrobiana frente a Candida albicans ATCC 10231. Os resultados apresentam perspectivas para aprimoramentos de formulações com fármacos pouco solúveis ou insolúveis em água, pesquisa de novos biomateriais e outras aplicações nas áreas farmacêutica e cosmética


Many patients with fungal infections succumb due to ineffectiveness or toxicity of antibiotics. Amphotericin B is one of the most efficient antifungals on the market despite its high toxicity. It presents polyenic structure and is a water-insoluble compound. In this case, it is necessary to use adjuvants and new technologies to prepare effective formulations. Ketoconazole is an imidazolic compound, also with broad spectrum antifungal action and difficult solubilization in aqueous medium but it is soluble at low pH values. Studies have demonstrated the use of bixin in the preparation of aqueous dispersions of insoluble or poorly soluble compounds in water. Bixin is the main compound of Bixa orellana (annatto) seed husks, being a water-insoluble carotenoid, but it allows preparations in the form of aqueous nanodispersions with incorporation of apolar or lipophilic drugs. The objective of this work was to prepare amphotericin B and ketoconazole as nanodispersions from bixin, using pullulan and trehalose as adjuvants and to evaluate them under aspects of stability and efficacy by physicochemical and microbiological assays. Pullulan is a polysaccharide consisting of maltotriose units with adhesive properties and ability to form biofilms, while trehalose is a compound with two glucose units with good stability at pH ranges from 3 to 10 and capable of withstanding high temperatures such as processes of sterilization by moist heat. Physicochemical tests demonstrated good maintenance of the characteristics of the preparations proposed in this project, such as hydrodynamic diameter and zeta potential of bixin and antifungal nanodispersions and also antimicrobial efficacy against Candida albicans ATCC 10231. The results present prospects for improvement. of poorly soluble or water-insoluble drug formulations, research on new biomaterials and other applications in the pharmaceutical and cosmetic fields


Assuntos
Trealose , Anfotericina B/agonistas , Crescimento e Desenvolvimento , Cetoconazol/efeitos adversos , Antibacterianos/análise , Pacientes , Preparações Farmacêuticas/análise , Antifúngicos/farmacocinética
4.
Electron. j. biotechnol ; 41: 88-94, sept. 2019. tab, ilus, graf
Artigo em Inglês | LILACS | ID: biblio-1087247

RESUMO

Background: In industrial yeasts, selection and breeding for resistance to multiple stresses is a focus of current research. The objective of this study was to investigate the tolerance to multiple stresses of Saccharomyces cerevisiae obtained through an adaptive laboratory evolution strategy involving a repeated liquid nitrogen freeze­thaw process coupled with multi-stress shock selection. We also assessed the related resistance mechanisms and very high-gravity (VHG) bioethanol production of this strain. Results: Elite S. cerevisiae strain YF10-5, exhibiting improved VHG fermentation capacity and stress resistance to osmotic pressure and ethanol, was isolated following ten consecutive rounds of liquid nitrogen freeze­thaw treatment followed by plate screening under osmotic and ethanol stress. The ethanol yield of YF10-5 was 16% higher than that of the parent strain during 35% (w/v) glucose fermentation. Furthermore, there was upregulation of three genes (HSP26, HSP30, and HSP104) encoding heat-shock proteins involved in the stress response, one gene (TPS1) involved in the synthesis of trehalose, and three genes (ADH1, HXK1, and PFK1) involved in ethanol metabolism and intracellular trehalose accumulation in YF10-5 yeast cells, indicating increased stress tolerance and fermentative capacity. YF10-5 also showed excellent fermentation performance during the simultaneous saccharification and fermentation of VHG sweet potato mash, producing 13.40% (w/ v) ethanol, which corresponded to 93.95% of the theoretical ethanol yield. Conclusions: A multiple-stress-tolerant yeast clone was obtained using adaptive evolution by a freeze­thaw method coupled with stress shock selection. The selected robust yeast strain exhibits potential for bioethanol production through VHG fermentation.


Assuntos
Saccharomyces cerevisiae/fisiologia , Etanol/síntese química , Saccharomyces cerevisiae/genética , Seleção Genética , Estresse Fisiológico , Trealose , Leveduras , Cruzamento , Adaptação Fisiológica , Hipergravidade , Fermentação , Reação em Cadeia da Polimerase em Tempo Real , Congelamento , Proteínas de Choque Térmico
5.
Arq. bras. oftalmol ; 81(6): 505-509, Nov.-Dec. 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-973848

RESUMO

ABSTRACT Purpose: This study aimed to compare the effectiveness of eye drops containing a combination of sodium hyaluronate and trehalose and sodium hyaluronate for the treatment of corneal cross-linking and epithelial healing. Methods: This study included 46 eyes of 23 keratoconus patients who underwent corneal cross-linking on both eyes. Unpreserved trehalose 30 mg/mL and sodium hyaluronate 1.5 mg/mL (Thealoz Duo®; Thea, France) were applied six times a day on one eye of each patient and unpreserved sodium hyaluronate 0.15% (Eye Still®; Teka, Inc., Istanbul) was applied on the other eye. Patients were examined daily until complete re-epithelialization. Postoperative examinations to assess the measured size of epithelial defect were performed using slit-lamp biomicroscopy. Results: The study included 23 patients (13 females and 10 males) with a mean age of 20.9 ± 10.3 years. Corneal epithelial healing time after cross-linking was 2.3 ± 1.2 days for the trehalose and sodium hyaluronate group and 3.8 ± 2.9 days for the sodium hyaluronate group (p=0.03). Conclusion: The application of eye drops containing the combination of trehalose and sodium hyaluronate resulted in faster corneal re-epithelialization following corneal cross-linking than that of eye drops containing sodium hyaluronate alone.


RESUMO Objetivo: Este estudo teve como objetivo comparar a eficácia de colírios contendo uma combinação de hialurônico de sódio e hialuronato de sódio e trealose para o tratamento da cicatrização epitelial em pacientes com cross-linking corneano. Métodos: Este estudo inclui 46 olhos de 23 pacientes com ceratocone, que foram operados com cross-linking corneano em ambos os olhos. Trealose não preservada 30 mg/mL e hialuronato de sódio 1,5 mg/mL (Thealoz Duo®; Thea, França) foram aplicados seis vezes por dia em um olho de cada paciente e hialuronato de sódio não conservado, 0,15% (Eye Still®; Teka, Inc., Istambul) foi aplicada no outro olho. Os pacientes foram examinados diariamente até a completa reepitelização. Exames pós-operatórios para avaliar o tamanho medido do defeito epitelial foram realizados usando biomicroscopia com lâmpada de fenda. Resultados: O estudo incluiu 23 pacientes (13 mulheres e 10 homens) com idade média de 20,9 ± 10,3. O tempo de cicatrização epitelial da córnea após o cross-linking foi de 2,3 ± 1,2 dias para o grupo trealose e hialuronato de sódio e 3,8 ± 2,9 dias para o grupo hialurônico de sódio (p=0,03). Conclusão: A aplicação de gotas para os olhos contendo combinação de trealose e hialuronato de sódio resultou em uma re-epitelização da córnea mais rápida após o cross-linking corneano do que a de gotas contendo hialurônico de sódio apenas.


Assuntos
Humanos , Masculino , Feminino , Adulto , Adulto Jovem , Trealose/farmacologia , Cicatrização/efeitos dos fármacos , Epitélio Corneano/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Reepitelização/efeitos dos fármacos , Soluções Oftálmicas/farmacologia , Cuidados Pós-Operatórios , Resultado do Tratamento , Epitélio Corneano/patologia , Reagentes de Ligações Cruzadas , Quimioterapia Combinada , Ácido Hialurônico/farmacologia , Ceratocone/cirurgia
6.
Braz. j. microbiol ; 49(supl.1): 185-192, 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-974316

RESUMO

Abstract Biosurfactants have many advantages over synthetic surfactants but have higher production costs. Identifying microorganisms with high production capacities for these molecules and optimizing their growth conditions can reduce cost. The present work aimed to isolate and identify a fungus with high biosurfactant production capacity, optimize its growth conditions in a low cost culture medium, and characterize the chemical structure of the biosurfactant molecule. The fungal strain UFSM-BAS-01 was isolated from soil contaminated with hydrocarbons and identified as Fusarium fujikuroi. To optimize biosurfactant production, a Plackett-Burman design and a central composite rotational design were used. The variables evaluated were pH, incubation period, temperature, agitation and amount of inoculum in a liquid medium containing glucose. The partial structure of the biosurfactant molecule was identified by nuclear magnetic resonance spectrometry. F. fujikuroi reduced surface tension from 72 to 20 mN m−1 under the optimized conditions of pH 5.0, 37 °C and 7 days of incubation with 190 rpm agitation. The partial identification of the structure of the biosurfactant demonstrated the presence of an α,β-trehalose. The present study is the first report of the biosynthesis of this compound by F. fujikuroi, suggesting that the biosurfactant produced belongs to the class of trehalolipids.


Assuntos
Tensoativos/metabolismo , Trealose/metabolismo , Microbiologia Industrial/métodos , Fusarium/metabolismo , Tensoativos/química , Temperatura , Meios de Cultura/metabolismo , Fermentação , Fusarium/crescimento & desenvolvimento , Fusarium/química , Concentração de Íons de Hidrogênio
7.
Rev. chil. cir ; 68(4): 295-301, jul. 2016. graf, tab
Artigo em Espanhol | LILACS | ID: lil-788897

RESUMO

Objetivo Obtener células estromales derivadas del tejido adiposo, medir y comparar las tasas de viabilidad antes e inmediatamente después un ciclo de criopreservación con diferentes combinaciones de criopreservantes de manera de obtener el mejor medio de criopreservación. Material y método Medición de la tasa de viabilidad poscriopreservación de células estromales derivadas del tejido adiposo obtenidas de 5 pacientes utilizando medios definidos (DMEM/Ham F12) libres de suero bovino y suplementados con una de los siguientes combinaciones de compuestos: dimetilsulfóxido (DMSO) 10%; DMSO 10% + trehalosa 7,6%; DMSO 10% + albúmina humana 10% y DMSO 10% + trehalosa 7,6% + albúmina humana 10%, mediante citometría de flujo con ioduro de propidio. Resultados No existen diferencias estadísticamente significativas en las tasas de viabilidad de las células estromales posterior a un ciclo de criopreservación. Sin embargo, se observa una tendencia a mejorar la tasa de recuperación de células vitales al agregar albúmina humana. Conclusiones No se observaron diferencias significativas entre las condiciones estudiadas, sugiriendo que ninguna es superior a las demás en cuanto a rendimiento. Es así como podemos afirmar que la criopreservación de las células estromales derivadas del tejido adiposo en un medio que combine DMEM/F12 con DMSO 10% + trehalosa 7,6% + albúmina humana 10% no logra una tasa de recuperación de células vitales significativamente mayor que las congeladas solo con DMSO 10%.


Aim To obtain stromal cells derived from adipose tissue, to measure and compare viability rates before and immediately after cryopreservation cycle, using different combinations of cryoprotective agents in order to identify the best cryopreservation medium. Material and method Viability rate after cryopreservation of stromal cells derived from adipose tissue were assessed by flow cytometry with propidium iodide. Samples of stromal cells obtained from 5 patients were kept defined, bovine serum-free media (DMEM/Ham-F12), supplemented with one of the following combinations of compounds: 10% dymethylsulfoxide (DMSO); Trehalose 10% DMSO + 7.6%; 10% DMSO + 10% human albumin and 10% DMSO + 7.6% Trehalose + 10% human albumin. Results No statistically significant differences were observed in the viability rates of stromal cells derived from adipose tissue after a cryopreservation cycle. However, we observed a tendency towards improvement of recovery rate when human albumin was added to the medium. Conclusions None of the studied conditions proved superior to others in terms of cell vitality after a cryopreservation cycle. Hence, we conclude that the cryopreservation of stromal cells derived from adipose tissue in an environment that combines DMEM/F12 with 10% DMSO + 7.6% Trehalose + human albumin 10% does not achieve a significantly higher recovery rate than only frozen solely with DMSO 10%.


Assuntos
Humanos , Criopreservação/métodos , Sobrevivência Celular/efeitos dos fármacos , Células Estromais/fisiologia , Crioprotetores/farmacologia , Trealose/farmacologia , Dimetil Sulfóxido/farmacologia , Tecido Adiposo/citologia , Albumina Sérica Humana/farmacologia , Congelamento
8.
Biosci. j. (Online) ; 30(6): 1882-1884, nov./dec. 2014. tab, ilus
Artigo em Inglês | LILACS | ID: biblio-948323

RESUMO

The extreme conditions in rocky outcrops allow the occurrence of desiccation tolerant species. One strategy of these plants to withstand water shortage is the accumulation of sugars. In this paper, we report sugar levels and profile of three ferns and one lycophyte naturally hydrated growing on rocky outcrops from Southeastern Brazil. Anemia species have higher sugar contents than Doryopteris collina and Selaginella sellowii. The analyzed species have different sugar profiles. The ferns have glucose, fructose and sucrose, and the lycophyte has glucose and trehalose.


Nas condições ambientais extremas dos afloramentos rochosos ocorrem espécies tolerantes à dessecação. Uma das estratégias dessas plantas para resistir à restrição hídrica é o acúmulo de açúcares. No presente estudo, avaliamos a concentração e o perfil de açúcares de três espécies de samambaias e uma licófita, naturalmente hidratadas crescendo sobre afloramentos rochosos no sudeste do Brasil. As espécies de Anemia possuem maior concentração de açúcares em relação a Doryopteris collina e Selaginella sellowii. As espécies analisadas mostraram perfis distintos de açúcares. As samambaias apresentam glicose, frutose e sacarose, enquanto a licófita glicose e trealose.


Assuntos
Sacarose , Trealose , Gleiquênias
9.
Braz. j. microbiol ; 43(1): 157-166, Jan.-Mar. 2012. ilus, tab
Artigo em Inglês | LILACS | ID: lil-622800

RESUMO

Saccharomyces cerevisiae S1, which is a locally isolated and improved strain showed viability at 40, 45 and 50ºC and produced ethanol at 40, 43 and 45ºC. When the cells were given heat shock at 45ºC for 30min and grown at 40ºC, 100% viability was observed for 60h, and addition of 200gl-1 ethanol has led to complete cell death at 30h. Heat shock given at 45ºC (for 30min) has improved the tolerance to temperature induced ethanol shock leading to 37% viability at 30h. when the cells were subjected to ethanol (200gl-1 for 30 min) and osmotic shock (sorbitol 300gl-1), trehalose contents in the cells were increased. The heat shocked cells showed better viability in presence of added ethanol. Soy flour supplementation has improved the viability of S. cerevisiae S1 to 80% in presence of 100gl-1 added ethanol and to 60% in presence of 300gl-1 sorbitol. In presence of sorbitol (200gl-1) and ethanol (50gl-1) at 40ºC, 46% viability was retained by S. cerevisiae S1 at 48h and it was improved to 80% by soy flour supplementation.


Assuntos
Etanol/análise , Etanol/isolamento & purificação , Viabilidade Microbiana , Saccharomyces cerevisiae/isolamento & purificação , Trealose/análise , Morte Celular , Métodos , Pressão Osmótica
10.
Rio de Janeiro; s.n; 2012. 61 p. tab, graf.
Tese em Português | LILACS | ID: lil-691500

RESUMO

O sangue do cordão umbilical e placentário (SCUP) tem sido usado como fonte de células-tronco hematopoiéticas (CTH) para reconstituir a função medular (hematopoiese). A maioria das vezes, esta modalidade de transplante requer a criopreservação das CTH, que permanecem congeladas até uma possível utilização futura. Na criopreservação de CTH, o reagente químico dimetilsulfóxido (DMSO) tem sido utilizado como um crioprotetor. No entanto, tem sido provado que DMSO tem efeitos tóxicos para o corpo humano. Muitos organismos na natureza possuem uma capacidade de sobreviver ao congelamento e à desidratação acumulando dissacarídeos, como a trealose e sacarose, por isso a trealose, tem sido investigada como um crioprotetor alternativo para diversos tipos celulares. Outro dano muito comum durante o congelamento é a formação de espécie reativas de oxigênio (ERO) que diminui a viabilidade celular, por isso a adição de bioantioxidantes na solução de criopreservação das células é passo muito importante. Este estudo foi dividido em duas fases na primeira foram avaliados os resultados obtidos com a adição de antioxidantes na solução de criopreservação das células de SCUP e na segunda fase avaliou-se a hipótese que a solução de criopreservação contendo trealose intracelular e extracelular melhora a recuperação e a viabilidade das células-tronco do SCUP, após a criopreservação. SCUP foi processado e submetido à criopreservação em soluções contendo na primeira fase: soluções com diferentes concentrações de DMSO (10%, 5% e 2,5%), assim como as combinações de DMSO (5%, 2,5%) com um dos dissacarídeos (60mmol/L) e ácido ascórbico e/ou catalase (10mg/mL); e na segunda fase: soluções contendo diferentes concentrações de DMSO (10% e 2,5%), assim como as combinações de DMSO (2,5%) com trealose intra (a trealose foi introduzida na célula por meio de lipossomas) e extracelular e soluções contendo trealose intra e extracelular sem DMSO, armazenados por duas semanas em N2L, e descongeladas...


The umbilical cord blood (UCB) has been used as a source of primitive hematopoietic stem cells (HSC) to reconstitute the hematopoiesis. Most often, it is required the cryopreservation of HSC, which remain frozen in banks for possible future use. For cryopreservation of HSC, the chemical reagent dimethylsulfoxide (DMSO) has been used as a cryoprotectant. Many organisms in nature have a capacity of survive freezing and dehydration by accumulating disaccharides, so the trehalose, has been actively investigated as an alternative cryoprotector, other damage which is very common during freezing is oxygen free radicals formation which decreases the cellular viability after thawing, so the addition of bioantioxidants in the solution of cryopreservation of cells is very important. This study was divided into two phases: first, we evaluated the results obtained with the addition of antioxidants in the solution for cryopreservation of cord blood cells and the second phase: evaluate the hypothesis that the cryopreservation solution containing intracellular and extracellular trehalose improves recovery and viability of cord blood stem cells after cryopreservation. UBC was processed and subjected to cryopreservation solutions containing for the first phase: solutions with different concentrations of DMSO (10%, 5% and 2.5%), as well as combinations of DMSO (5%, 2.5 %) with a disaccharide (60 mmol/L), ascorbic acid and/or catalase (10mg/mL), and for the second phase: solutions containing different concentrations of DMSO (10% and 2.5%), as well as combinations of DMSO (2.5%) with intracellular trehalose (trehalose was introduced into the cell by means of liposomes) and solutions containing extra and intracellular trehalose without DMSO, stored for two weeks in N2L, and thawed. The thawed cells were assessed by flow cytometry, MTT and colony forming units (CFU) assays. In the first phase of the study our analysis showed catalase improved the preservation CD34+ and CD123+...


Assuntos
Humanos , Masculino , Feminino , Criopreservação/métodos , Sangue Fetal/citologia , Trealose/farmacologia , Antioxidantes/administração & dosagem , Sobrevivência Celular , Ensaio de Unidades Formadoras de Colônias , Catalase/administração & dosagem , Células-Tronco Hematopoéticas , Crioprotetores/farmacologia , Dimetil Sulfóxido , Dimetil Sulfóxido/farmacologia , Sangue Fetal
11.
Braz. j. microbiol ; 39(1): 50-55, Jan.-Mar. 2008. tab
Artigo em Inglês | LILACS | ID: lil-480673

RESUMO

Probiotics are viable defined microorganisms (bacteria or yeasts) that exert a beneficial effect on the health of the host when ingested in adequate amounts. Screening for such biotherapeutic agents is commonly performed by in vitro assays simulating gastrointestinal environment to determine the ability to survive in the digestive tract. In the present study, the possibility of extrapolation of data obtained in in vitro assays to in vivo conditions was studied using five Saccharomyces cerevisiae strains isolated from Brazilian Atlantic rain forest. Trehalose contents and survival after exposure to a combination of physiological stresses generally found in the gastrointestinal tract of humans were determined for the five yeasts and compared to the behavior of Saccharomyces boulardii, a well-known probiotic. The results were completed with the colonization capacity of the gastrointestinal tract of gnotobiotic mice by these yeast strains. Some results obtained by in vitro assays are not confirmed by in vivo experiments, indicating that the extrapolation cannot be always done.


Probióticos são definidos como microrganismos (bactérias e leveduras) que exercem um efeito benéfico na saúde do hospedeiro quando ingeridos em quantidades adequadas. A seleção desses agentes bioterapêuticos normalmente é feita por testes in vitro simulando o ambiente gastrointestinal que determina a capacidade de sobrevivência no trato digestivo. Neste trabalho, a possibilidade de extrapolação dos dados obtidos nos testes in vitro para as condições in vivo foi estudada utilizando cinco linhagens de Saccharomyces cerevisiae isoladas da floresta Atlântica brasileira. O conteúdo de trealose e a sobrevivência após a exposição a diversos estresses fisiológicos geralmente encontrados no trato gastrointestinal de humanos foram determinados para as cinco linhagens e os resultados comparados com a Saccharomyces boulardii, um probiótico conhecido. Esses resultados foram completados com a capacidade de colonização do trato gastrointestinal de camundongos gnotobióticos pelas leveduras. Pelos resultados obtidos, concluimos que os testes in vitro não são confirmados pelos ensaios in vivo, indicando que essa extrapolação não pode sempre ser feita.


Assuntos
Animais , Técnicas In Vitro , Micoses , Probióticos/isolamento & purificação , Saccharomyces cerevisiae/isolamento & purificação , Saccharomyces/isolamento & purificação , Técnicas e Procedimentos Diagnósticos , Trealose/análise , Leveduras , Métodos , Estresse Mecânico
12.
Rev. argent. microbiol ; 36(1): 41-46, Jan.-Mar. 2004. ilus, tab
Artigo em Espanhol | LILACS | ID: lil-634457

RESUMO

La actividad panificante valorada como producción de CO2 de dos cepas comerciales de Saccharomyces cerevisiae pudo ser incrementada, principalmente en amasijos azucarados, por la aplicación de un esquema de “hambreado/ pulso¼ de melaza de caña de azúcar durante su propagación bajo la forma de lote alimentado. Dicho incremento fue dependiente de la cepa utilizada. Otras características relacionadas con el comportamiento industrial de las levaduras no se vieron afectadas, con excepción de la concentración intracelular de trehalosa.Se discute la aplicabilidad del método para la producción industrial de levaduras de panificación.


Baking activity determined as CO2 production of two commercial strains of Saccharomyces cerevisiae could be increased mainly in sweet bread doughs by introducing a “starvation/ pulse feeding” schedule of sugar cane molasses during a fed-batch propagation . Such increase was strain dependent. Except for the trehalose intracellular level, other traits related to the yeast industrial performance were unaffected. Applicability of method for baker‘s yeast industrial production is discussed.


Assuntos
Dióxido de Carbono/metabolismo , Microbiologia Industrial/métodos , Micologia/métodos , Saccharomyces cerevisiae/crescimento & desenvolvimento , Pão , Metabolismo dos Carboidratos , Dióxido de Carbono/análise , Fermentação , Melaço , Saccharomyces cerevisiae/metabolismo , Trealose/metabolismo
13.
Braz. j. microbiol ; 34(3)July-Sept. 2003. tab, graf
Artigo em Inglês | LILACS | ID: lil-363929

RESUMO

A fermentacão dos carboidratos de reserva, glicogênio e trealose é um procedimento para aumentar o nível de proteína das células de leveduras com simultâneo aumento na producão de etanol. Este trabalho estudou a cinética de degradacão do glicogênio e trealose em duas linhagens industriais de Saccharomyces cerevisiae (PE-2 e SA-1), bem como o efeito de diferentes temperaturas (38º, 40º, 42º e 44ºC) na velocidade de degradacão. A fermentacão endógena foi conduzida com suspensão de leveduras a 20 per center (m/v) em massa úmida, no vinho com 3 a 4,5 per center (v/v) de etanol. A degradacão dos carboidratos de reserva, a 40ºC, seguiu uma cinética de primeira ordem, mostrando que sua taxa é dependente da concentracão dos carboidratos na célula. A taxa especifica de degradacão (k) variou de 0,0387 a 0,0746 h-1. Em relacão a outros parâmetros analisados a 40ºC, foi observado que a viabilidade e biomassa seca e úmida foram reduzidas, enquanto a reserva de proteína celular e etanol, glicerol e nitrogênio no meio aumentaram. A degradacão do glicogênio e trealose em diferentes temperaturas (38ºC, 40ºC, 42ºC e 44ºC) mostrou que a 38ºC a taxa de degradacão foi a menor, ao passo que a partir de 42ºC ou superior, a degradacão do glicogênio não mais progrediu após poucas horas de incubacão. Portanto, do ponto de vista prático, a melhor temperatura de incubacão é em torno de 40ºC. A aplicacão da equacão de Arrheniusmostrou que as energias de ativacão de 40ºC a 42ºC foram 165,90 e 107,94 kcal.ºK-1.mol-1 para trealose e glicogênio respectivamente para a linhagem PE-2, e 190,64 e 149,87 kcal.ºK-1/mol-1, para a linhagem SA-1 respectivamente.


Assuntos
Glicogênio/metabolismo , Saccharomyces cerevisiae , Trealose , Análise de Variância , Fermentação , Glicogênio/análise , Temperatura , Trealose
14.
Braz. j. med. biol. res ; 36(7): 829-837, July 2003. tab, graf
Artigo em Inglês | LILACS | ID: lil-340686

RESUMO

Trehalose biosynthesis and its hydrolysis have been extensively studied in yeast, but few reports have addressed the catabolism of exogenously supplied trehalose. Here we report the catabolism of exogenous trehalose by Candida utilis. In contrast to the biphasic growth in glucose, the growth of C. utilis in a mineral medium with trehalose as the sole carbon and energy source is aerobic and exhibits the Kluyver effect. Trehalose is transported into the cell by an inducible trehalose transporter (K M of 8 mM and V MAX of 1.8 æmol trehalose min-1 mg cell (dry weight)-1. The activity of the trehalose transporter is high in cells growing in media containing trehalose or maltose and very low or absent during the growth in glucose or glycerol. Similarly, total trehalase activity was increased from about 1.0 mU/mg protein in cells growing in glucose to 39.0 and 56.2 mU/mg protein in cells growing in maltose and trehalose, respectively. Acidic and neutral trehalase activities increased during the growth in trehalose, with neutral trehalase contributing to about 70 percent of the total activity. In addition to the increased activities of the trehalose transporter and trehalases, growth in trehalose promoted the increase in the activity of alpha-glucosidase and the maltose transporter. These results clearly indicate that maltose and trehalose promote the increase of the enzymatic activities necessary to their catabolism but are also able to stimulate each other's catabolism, as reported to occur in Escherichia coli. We show here for the first time that trehalose induces the catabolism of maltose in yeast


Assuntos
Candida , Maltose , Trealase , Trealose , Candida , Divisão Celular , Meios de Cultura , Fatores de Tempo
15.
Braz. j. microbiol ; 33(3): 202-208, July-Sept. 2002. tab
Artigo em Inglês | LILACS | ID: lil-349768

RESUMO

Trehalose accumulation, invertase activity and physiological characteristics of 86 yeast isolates from short fermentative cycles during the production of cachaça in three artisanal distilleries of the State of Minas Gerais were studied. Among these isolates, 70 percent were able to grow at temperatures between 40 and 42ºC. Only Saccharomyces cerevisiae isolates were able to grow over 40ºC. Lower temperatures (<40ºC) favoured the growth of yeasts such as Candida parapsilosis-like, C. maltosa-like, Kloeckera japonica, S. exiguus and C. bombicola-like. The isolates from all three distilleries were ethanol tolerant, produced invertase, and accumulate trehalose in the presence of glucose. The strains isolated from distillery A presented more resistance to ethanol (around 84.2 percent of the strains were able to grow in the presence of 12 percent ethanol) when compared to the ones from distilleries C and B (9.5 percent and no strain, respectively). The strains of S. cerevisiae isolated from the three distilleries presented a higher capacity to produce invertase and accumulate trehalose in the presence of glucose. Based on the results of thermal and ethanol stress experiments, it was possible to identify strong relationship between intracellular trehalose accumulation and cell viability. The increase in cell viability was even more pronounced when the strains were subjected to a pre-treatment at sublethal temperatures


Assuntos
Bebidas Alcoólicas , Etanol , Técnicas In Vitro , Saccharomyces cerevisiae , Trealose , Leveduras , Fermentação , Métodos
16.
Braz. j. med. biol. res ; 29(7): 873-5, July 1996.
Artigo em Inglês | LILACS | ID: lil-181498

RESUMO

Water is usually thought to be required for the living state, but many organisms can withstand anhydrobiosis When essentially all of their body water has been removed. The mechanisms for survival to this Kind of stress could be similar in microbes, plants and animals. One common feature is the accumulation of sugars by anhydrobiotic organisms. Trehalose, which is one of the most effective saccharides in preventing phase transition events in the lipid bilayer, is accumulated by anhydrobiotic organisms in large amounts. It lowers membrane phase transitions in dry yeast cells, thus preventing imbibitional damages when cells are rehydrated. Yeast cells have a trehalose carrier in the plasma membrane which endows them with the ability to protect both sides of the membrane. Kinetic analysis of the trehalose transport activity in Saccharomyces cerevisiae cells revealed the exoistence of a multicomponent system with a constitutive low-affinity uptake component and a high-affinity H+ - trehalose symporter regulated by glucose repression.


Assuntos
Células/metabolismo , Desidratação/metabolismo , Saccharomyces cerevisiae/metabolismo , Estresse Fisiológico/metabolismo , Trealose/metabolismo , Bicamadas Lipídicas , Lipídeos de Membrana , Fosfolipídeos , Saccharomyces cerevisiae/citologia , Trealose/farmacocinética , Trealose/fisiologia
17.
Braz. j. med. biol. res ; 28(2): 169-81, Feb. 1995.
Artigo em Inglês | LILACS | ID: lil-154261

RESUMO

Trehalose is responsible for the survival of anhydrobiotic organisms when under stress. Trehalose is a unique, non-reducing, extremely stable disaccharide which is able to protect proteins and membranes from damage caused freezing, high temperatures and dehydration. Yeasts accumulate large amounts of trehalose and constitue excellent models for studying the response of eurocaryotic cells to diverse stresses. The regulation of trehalose metabolism is reviwed and new technological applications for preservation of biological materials are discussed


Assuntos
Animais , Preservação Biológica , Saccharomyces cerevisiae/metabolismo , Trealose/metabolismo , Membrana Celular/fisiologia , Temperatura , Trealose/biossíntese
18.
Braz. j. med. biol. res ; 27(3): 627-36, Mar. 1994. tab, graf
Artigo em Inglês | LILACS | ID: lil-148935

RESUMO

1. Trehalase was partially purified from Escherichia coli and characterized. The Km for trehalose was 0.78 mM, the pH optimum 5.5 and the temperature optimum 30 degrees C. 2. Trehalase represented approximately 50 per cent of the total protein released by osmotic shock. The preparation was free of nonspecific carbohydrate hydrolases, which act on sucrose, galactose and maltose, permitting trehalose determination in biological samples, such as insect hemolymph and free cell extracts among others. 3. The enzyme was stable in 50 mM maleate buffer, pH 6.2, at -8 degrees C for at least 6 months and could be used to determine trehalose in the range of 6 to 30 nmol. 4. Immobilization of the enzyme was achieved by covalent linkage to spherisorb-5NH2 (spherical silica gel). Retention of total catalytic activity averaged 32 per cent . 5. The reactor, stored for one month at -5 degrees C, retained 98 per cent of its initial immobilized activity. 6. This immobilized form of the enzyme could be used routinely for specific determinations of trehalose


Assuntos
Enzimas Imobilizadas/isolamento & purificação , Escherichia coli/enzimologia , Trealase/isolamento & purificação , Eletroforese em Gel de Poliacrilamida , Ativação Enzimática , Enzimas Imobilizadas/metabolismo , Temperatura Alta , Dióxido de Silício , Fatores de Tempo , Trealase/metabolismo , Trealose/análise
19.
Braz. j. med. biol. res ; 23(2): 105-11, 1990. ilus, tab
Artigo em Inglês | LILACS | ID: lil-85147

RESUMO

As the first part of a study of pesticide toxicity we report the effects of the solvent dimethylsulfoxide (DMSO) on signal transduction in mutants of Saccharomyces cerevisiae. The enzymes of trehalose metabolism, which are activated and deactivated by a "glucose signal" and by heat shock treatment, were chosen as targets for this study. DMSO was shown to be able to permeate glucose and cAMP. The effects of glucose and cAMP were enhanced by pre-incubating the cells in the presence of DMSO. No effects were observed during the heat shock, suggesting that the solvent acts on the cell membrane. The results suggest that DMSO may be used as a vehicle for small molecules which do not easily penetrate yeast cell membranes, thus providing a new tool for biochemical and toxicological studies


Assuntos
Dimetil Sulfóxido/farmacologia , Glucose/metabolismo , Mutação/genética , Saccharomyces cerevisiae/genética , Transdução de Sinais , Trealose/metabolismo , AMP Cíclico/metabolismo , Ativação Enzimática , Temperatura Alta
20.
Braz. j. med. biol. res ; 22(2): 171-7, 1989. tab
Artigo em Inglês | LILACS | ID: lil-105573

RESUMO

1. A regulatory mutant of Sccharomyces (fdp) unable to activate fructose 1,6-bisphosphatase present a normal response to the glucose and fructose signals as measured by trehalase activation, indicating that the inability of the strain to grow on these sugars is caused by a defect located beyond membrane interactions. 2. In vivo experiments with a mutant strain bearing a phosphoglucoisomerase gene (pgil-delta) deletion showed that activation of trehalase and deactivation of the tehalose-6-phosphate synthase complex occurred to the same extent whether glucose or fructose was used as signal. 3. These results suggest that fructose-2,6-bisphosphate is not involved in the interconversion of forms of the enzymes of trehalose metabolism. Furthermore, when fructose-2,6-bisphosphate was assayed on trehalose synthesizing activity using cell-free extracts and partially purified preparations of the complex, no effect was observed. 4. We conclude that regulation by cAMP fulfills the requirements for control of trehalose levels in Saccharomyces


Assuntos
AMP Cíclico/metabolismo , Dissacarídeos/metabolismo , Frutosedifosfatos/metabolismo , Hexosedifosfatos/metabolismo , Saccharomyces cerevisiae/genética , Trealose/metabolismo , Ativação Enzimática , Glucose/metabolismo , Proteínas Quinases/metabolismo , Saccharomyces cerevisiae/crescimento & desenvolvimento
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