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1.
Med. intensiva (Madr., Ed. impr.) ; 41(1): 28-37, ene.-feb. 2017. graf, tab
Artículo en Inglés | IBECS | ID: ibc-160093

RESUMEN

OBJECTIVE: To analyze the evolution of sepsis-related mortality in Spanish Intensive Care Units (ICUs) following introduction of the Surviving Sepsis Campaign (SSC) guidelines and the relationship with sepsis process-of-care. DESIGN: A prospective cohort study was carried out, with the inclusion of all consecutive patients presenting severe sepsis or septic shock admitted to 41 Spanish ICUs during two time periods: 2005 (Edusepsis study pre-intervention group) and 2011 (ABISS-Edusepsis study pre-intervention group). Scope: Patients with severe sepsis or septic shock admitted to Spanish ICUs. PATIENTS: All ICU admissions from the emergency department or wards and all ICU patients with a diagnosis of severe sepsis or septic shock. A total of 1348 patients were included: 630 in the 2005 group and 718 in the 2011 group. Intervention: None. Primary endpoints: ICU mortality, 28-day mortality and Hospital mortality, hospital length of stay, ICU length of stay and compliance with the resuscitation bundle. RESULTS: Compliance with the resuscitation bundle was significantly greater in the 2011 group (5.7% vs. 9.9%; p = 0.005), and was associated to lower mortality (OR 0.602 [0.365-0.994]; p = 0.048). The 2011 group had lower absolute in-hospital mortality (44.0% vs. 32.6%; p = 0.01), 28-day mortality (36.5% vs. 23.0%; p = 0.01), and adjusted mortality (OR 0.64 [0.49-0.83], p = 0.001). CONCLUSIONS: Mortality related to severe sepsis or septic shock in Spain decreased between two patient cohorts in 2005 and 2011, and was attributable to earliness and improvement in sepsis care


OBJETIVO: Analizar la evolución de la mortalidad relacionada con la sepsis en las unidades de cuidados intensivos (UCI) españolas desde la introducción de las directrices Surviving Sepsis Campaing y la relación con el proceso de atención de la sepsis. DISEÑO: Estudio prospectivo de cohortes. Se incluyeron de manera consecutiva, todos los pacientes con sepsis grave o shock séptico ingresados en 41 UCI españolas durante 2 periodos de tiempo: en 2005 (grupo pre-intervención en el estudio Edusepsis) y en 2011 (grupo pre-intervención en el estudio ABISS-Edusepsis). Ámbito: Pacientes con sepsis grave o shock séptico ingresados en las UCI españolas. PACIENTES: Todos los ingresos en UCI procedentes de Urgencias o planta y todos los pacientes de UCI con diagnóstico de sepsis grave/shock séptico. Se incluyeron 1348 pacientes: 630 del grupo de 2005 y 718 del grupo de 2011. Intervención: Ninguna. Variables de interés principal: Mortalidad en UCI, a 28 días y hospitalaria, estancia en la UCI y en el hospital y cumplimiento con el bundle de reanimación. RESULTADOS: El cumplimiento del bundle de reanimación fue significativamente mayor en el grupo de 2011 (5,7 frente a 9,9%, p = 0,005) y se asoció con una menor mortalidad (OR 0,602 [0,365 a 0,994], p = 0,048). El grupo de 2011 tuvo una menor mortalidad absoluta hospitalaria (44,0 frente a 32,6%, p = 0,01), mortalidad a los 28 días (36,5 frente a 23,0%, p = 0,01) y mortalidad ajustada (OR 0,64 [0,49 a 0,83], p = 0,001). CONCLUSIONES: La mortalidad relacionada con la sepsis grave y el shock séptico en España disminuyó entre las 2 cohortes de pacientes de 2005 y 2011, atribuible a la precocidad y las mejoras en la atención de la sepsis


Asunto(s)
Humanos , Sepsis/mortalidad , Choque Séptico/mortalidad , Unidades de Cuidados Intensivos/estadística & datos numéricos , Evaluación de Procesos y Resultados en Atención de Salud , Mortalidad/tendencias , Cuidados Críticos/estadística & datos numéricos , Estudios de Cohortes
2.
Med Intensiva ; 41(1): 28-37, 2017.
Artículo en Inglés, Español | MEDLINE | ID: mdl-28029501

RESUMEN

OBJECTIVE: To analyze the evolution of sepsis-related mortality in Spanish Intensive Care Units (ICUs) following introduction of the Surviving Sepsis Campaign (SSC) guidelines and the relationship with sepsis process-of-care. DESIGN: A prospective cohort study was carried out, with the inclusion of all consecutive patients presenting severe sepsis or septic shock admitted to 41 Spanish ICUs during two time periods: 2005 (Edusepsis study pre-intervention group) and 2011 (ABISS-Edusepsis study pre-intervention group). SCOPE: Patients with severe sepsis or septic shock admitted to Spanish ICUs. PATIENTS: All ICU admissions from the emergency department or wards and all ICU patients with a diagnosis of severe sepsis or septic shock. A total of 1348 patients were included: 630 in the 2005 group and 718 in the 2011 group. INTERVENTION: None. PRIMARY ENDPOINTS: ICU mortality, 28-day mortality and Hospital mortality, hospital length of stay, ICU length of stay and compliance with the resuscitation bundle. RESULTS: Compliance with the resuscitation bundle was significantly greater in the 2011 group (5.7% vs. 9.9%; p=0.005), and was associated to lower mortality (OR 0.602 [0.365-0.994]; p=0.048). The 2011 group had lower absolute in-hospital mortality (44.0% vs. 32.6%; p=0.01), 28-day mortality (36.5% vs. 23.0%; p=0.01), and adjusted mortality (OR 0.64 [0.49-0.83], p=0.001). CONCLUSIONS: Mortality related to severe sepsis or septic shock in Spain decreased between two patient cohorts in 2005 and 2011, and was attributable to earliness and improvement in sepsis care.


Asunto(s)
Mortalidad Hospitalaria/tendencias , Unidades de Cuidados Intensivos/estadística & datos numéricos , Paquetes de Atención al Paciente , Sepsis/mortalidad , APACHE , Anciano , Anciano de 80 o más Años , Femenino , Adhesión a Directriz , Promoción de la Salud , Hospitales Universitarios/estadística & datos numéricos , Humanos , Tiempo de Internación/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Modelos Teóricos , Guías de Práctica Clínica como Asunto , Evaluación de Programas y Proyectos de Salud , Estudios Prospectivos , Sepsis/complicaciones , Choque Séptico/complicaciones , Choque Séptico/mortalidad , España/epidemiología , Centros de Atención Terciaria/estadística & datos numéricos
3.
Bone Marrow Transplant ; 51(8): 1076-81, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27042850

RESUMEN

High-dose chemotherapy (HDC) was investigated in high-risk neuroblastoma (HR-NBL) to reduce the risk of relapse. We report the results of the 30-year experience of a cohort of patients with HR-NBL treated with high-dose (HD) busulfan (Bu)-containing regimens. From 1980 to 2009, 215 patients aged >1 year with stage 4 NBL were treated with HD Bu-containing regimens at Gustave Roussy. These data were prospectively recorded in the Pediatric Transplantation Database. The median age at diagnosis was 40 months (12-218 months). All patients had a stage 4 neuroblastoma. NMYC amplification was displayed in 24% of the tumors. The hematopoietic support consisted of bone marrow or PBSCs in 46% and 49% of patients, respectively. The 5-year event-free survival and overall survival rates of the whole cohort were 35.1% and 40%, respectively. Age at diagnosis, bone marrow involvement and tumor response after induction chemotherapy were significant prognostic factors. Toxicity was manageable and decreased over time, owing to both PBSC administration and better supportive care. Based on this experience, HD Bu-melphalan (Mel) has been implemented in Europe and compared with Carboplatin-Etoposide-Mel in the European SIOP Neuroblastoma (SIOPEN)/HR-NBL randomized protocol. It has now become the standard HDC in the SIOPEN HR strategy.


Asunto(s)
Busulfano/administración & dosificación , Melfalán/administración & dosificación , Neuroblastoma/terapia , Adolescente , Trasplante de Médula Ósea/métodos , Busulfano/toxicidad , Niño , Preescolar , Estudios de Cohortes , Terapia Combinada , Femenino , Humanos , Lactante , Masculino , Melfalán/toxicidad , Neuroblastoma/complicaciones , Neuroblastoma/mortalidad , Trasplante de Células Madre de Sangre Periférica/métodos , Trasplante de Células Madre de Sangre Periférica/mortalidad , Estudios Retrospectivos , Factores de Riesgo , Análisis de Supervivencia
4.
Bone Marrow Transplant ; 51(2): 227-31, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26524264

RESUMEN

High-risk neuroblastoma is characterised by poor long-term survival, especially for very high-risk (VHR) patients (poor response of metastases after induction therapy). We report the results of an intensified high-dose chemotherapy (HDC) strategy to improve the prognosis of VHR patients. This strategy was based on tandem HDC with thiotepa and busulfan-melphalan (Bu-Mel) followed by autologous stem cell transplantation (ASCT). All data were prospectively recorded in the Gustave Roussy Paediatric ASCT database. From April 2004 to August 2011, 26 patients were eligible for tandem HDC. The median age at diagnosis was 4.4 years (1-15.9). All patients had metastatic disease. MYCN was amplified in 5/26 tumours. Despite the cumulative toxicity of alkylating agents, the toxicity of the intensified HDC strategy was manageable. Thiotepa-related toxicity was mainly digestive, whereas sinusoidal obstruction syndrome was the main toxicity observed after Bu-Mel. The 3-year event-free survival of this cohort was 37.3% (21.3-56.7). This strategy will be compared with combined (131)I-mIBG/Bu-Mel in the upcoming SIOPEN VHR Neuroblastoma Protocol.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Neuroblastoma , Trasplante de Células Madre , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Autoinjertos , Busulfano/administración & dosificación , Busulfano/efectos adversos , Niño , Preescolar , Supervivencia sin Enfermedad , Femenino , Humanos , Lactante , Masculino , Melfalán/administración & dosificación , Melfalán/efectos adversos , Neuroblastoma/mortalidad , Neuroblastoma/terapia , Estudios Retrospectivos , Tasa de Supervivencia , Tiotepa/administración & dosificación , Tiotepa/efectos adversos
5.
Bone Marrow Transplant ; 50(8): 1083-8, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26030048

RESUMEN

The prognosis of primary disseminated multifocal metastatic Ewing's sarcoma (PDMES) is poor even if a slight improvement has been achieved with high-dose alkylating agent-containing chemotherapy. To enhance treatment efficacy, we assessed the feasibility, safety and efficacy of a tandem high-dose chemotherapy (HDC) regimen. In a single institution, patients with PDMES received six courses of vincristine/ifosfamide/doxorubicin/etoposide induction therapy, followed by high-dose thiotepa, and then melphalan-busulfan, 8 weeks apart. Surgical resection of primary tumour was carried out between the two HDC regimens and 70 days after the last HDC regimen for post-operative radiotherapy or irradiation alone. From October 2002 to 2009, 13 of the 18 consecutive patients with PDMES (72%) received the full treatment programme. The other five patients experienced early progression and died. Among the 13 patients, 11 relapsed after the end of the treatment programme within 6 months (2.2-11.9) from end of therapy. Only two patients are still alive in first complete remission after 9 years. The 3-year event-free survival (EFS) and overall survival (OS) rates were 11 and 22%, respectively. The median EFS and OS duration from the diagnosis were 13.4 and 17.3 months, respectively. Neither major complications nor treatment-related death occurred. The tandem-HDC regimen was feasible, with expected side effects, but it did not improve the outcome of patients with PDMES.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Quimioradioterapia/métodos , Sarcoma de Ewing/mortalidad , Sarcoma de Ewing/terapia , Adolescente , Adulto , Niño , Preescolar , Supervivencia sin Enfermedad , Doxorrubicina/administración & dosificación , Etopósido/administración & dosificación , Femenino , Estudios de Seguimiento , Humanos , Ifosfamida/administración & dosificación , Masculino , Tasa de Supervivencia , Tiotepa/administración & dosificación , Vincristina/administración & dosificación , Adulto Joven
6.
Bioprocess Biosyst Eng ; 32(4): 459-66, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18923846

RESUMEN

Dynamic Saccharomyces cerevisiae responses to increasing ethanol stresses were investigated to monitor yeast viability and to optimize bioprocess performance when gradients occurred due to the specific configuration of multi-stage bioreactors with cell recycling or of large volume industrial bioreactors inducing chemical heterogeneities. Twelve fed-batch cultures were carried out with initial ethanol concentrations (P(in)) ranging from 5 g l(-1) to 110 g l(-1) with three different inoculums in different physiological states in terms of viability and quantity of ethanol produced (P(o)). For a given initial cell viability of 50%, the time to reach the maximum growth rate and maximum ethanol production rate was dependent on the difference P(in) - P(o). Whatever the initial physiological state, when the initial ethanol concentration P(in) reached 100 g l(-1), the yeasts died. Experimental results showed that the initial physiological state of the yeast was the major parameter to determine, the microorganisms' capacities to adapt and resist environmental changes.


Asunto(s)
Reactores Biológicos/microbiología , Etanol/metabolismo , Etanol/farmacología , Saccharomyces cerevisiae/efectos de los fármacos , Saccharomyces cerevisiae/fisiología , Ingeniería Biomédica , Fermentación , Cinética , Saccharomyces cerevisiae/crecimiento & desarrollo , Estrés Fisiológico
7.
Bioprocess Biosyst Eng ; 28(1): 55-61, 2005 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-16195896

RESUMEN

Spiramycin production by Streptomyces ambofaciens Sp181110 with glucose as the carbon source was studied under a controlled nutritional environment. In a batch culture, the glucose excess after ammonium depletion led to pyruvate and alpha-ketoglutarate accumulation. 85 mg/l of spiramycin were produced in less than 70 h during the stationary and maintenance phase on these acids after glucose exhaustion. Fed-batch strategy was designed to study spiramycin production without by-product formation and glucose accumulation. In these conditions, up to 150 mg/l were produced in less than 80 h during the stationary phase on glucose. The antibiotic titre was found independent of the glucose feeding under carbon limitation and the importance of putative intracellular reserves formed after nutrient exhaustion was suggested. Besides, spiramycin production was not inhibited by the limiting flux of glucose.


Asunto(s)
Reactores Biológicos/microbiología , Técnicas de Cultivo de Célula/métodos , Glucosa/metabolismo , Modelos Biológicos , Espiramicina/biosíntesis , Streptomyces/crecimiento & desarrollo , Streptomyces/metabolismo , Biomasa , Proliferación Celular , Simulación por Computador , Especificidad de la Especie , Streptomyces/clasificación
8.
Bioprocess Biosyst Eng ; 26(4): 217-22, 2004 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15098119

RESUMEN

The impact of ethanol and temperature on the dynamic behaviour of Saccharomyces cerevisiae in ethanol biofuel production was studied using an isothermal fed-batch process at five different temperatures. Fermentation parameters and kinetics were quantified. The best performances were found at 30 and 33 degrees C around 120 g l(-1) ethanol produced in 30 h with a slight benefit for growth at 30 degrees C and for ethanol production at 33 degrees C. Glycerol formation, enhanced with increasing temperatures, was coupled with growth for all fermentations; whereas, a decoupling phenomenon occurred at 36 and 39 degrees C pointing out a possible role of glycerol in yeast thermal protection.


Asunto(s)
Reactores Biológicos/microbiología , Técnicas de Cultivo de Célula/métodos , Etanol/metabolismo , Glicerol/metabolismo , Saccharomyces cerevisiae/fisiología , Temperatura , Proliferación Celular , Supervivencia Celular/fisiología , Cinética
9.
Appl Microbiol Biotechnol ; 63(5): 537-42, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-12879304

RESUMEN

In order to identify an optimal aeration strategy for intensifying bio-fuel ethanol production in fermentation processes where growth and production have to be managed simultaneously, we quantified the effect of aeration conditions--oxygen limited vs non limited culture (micro-aerobic vs aerobic culture)--on the dynamic behaviour of Saccharomyces cerevisiae cultivated in very high ethanol performance fed-batch cultures. Fermentation parameters and kinetics were established within a range of ethanol concentrations (up to 147 g l(-1)), which very few studies have addressed. Higher ethanol titres (147 vs 131 g l(-1) in 45 h) and average productivity (3.3 vs 2.6 g l(-1) h(-1)) were obtained in cultures without oxygen limitation. Compared to micro-aerobic culture, full aeration led to a 23% increase in the viable cell mass as a result of the concomitant increase in growth rate and yield, with lower ethanol inhibition. The second beneficial effect of aeration was better management of by-product production, with production of glycerol, the main by-product, being strongly reduced from 12 to 4 g l(-1). We demonstrate that aeration strategy is as much a determining factor as vitamin feeding (Alfenore et al. 2002) in very high ethanol performance (147 g l(-1) in 45 h) in order to achieve a highly competitive dynamic process.


Asunto(s)
Etanol/metabolismo , Saccharomyces cerevisiae/crecimiento & desarrollo , Saccharomyces cerevisiae/metabolismo , Aerobiosis , Aire , Biomasa , Reactores Biológicos , Medios de Cultivo , Etanol/análisis , Fermentación , Glucosa/metabolismo , Glicerol/metabolismo , Microbiología Industrial/métodos , Cinética , Consumo de Oxígeno , Factores de Tiempo , Vitaminas/farmacología
10.
Environ Technol ; 24(8): 979-87, 2003 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-14509389

RESUMEN

Results of ready biodegradability tests (RBT) are barely reproducible owing to a well-known lack of definition in inoculum source and quality. In this study, the degree of variability expected when only activated sludges are used as inoculum source was investigated. For this, the characteristics of activated sludges collected in municipal wastewater treatment plants operating at various massic loading rates (MLR; 0.1, 0.5 and 0.9 kgBOD5 kgVSS(-1) d(-1)) were compared. In order to provide suitable cellular densities for RBT, inocula were obtained after settling of activated sludges and analyzed in terms of active and cultivable cell densities, dehydrogenasic activity, BOD5 and a general profile of hydrolytic enzymes. In our analysis, biomass obtained from the High-MLR treatment plant constituted the inoculum having the highest biodegradation potential both with respect to microbial densities and to enzyme activities. This biomass also yielded the fastest biodegradation kinetics in dodecyl benzene sulfonate RBT. An attempt of biomass homogenization of inocula on the basis of cultivable cell density and dehydrogenasic activity gave negative results with this chemical compound. Since, in practice, restriction of activated sludge sources may be difficult, our results emphasize the importance of further studies aimed at homogenization of inoculum quality and quantity.


Asunto(s)
Aguas del Alcantarillado/microbiología , Eliminación de Residuos Líquidos/métodos , Biodegradación Ambiental , Compuestos Orgánicos/metabolismo , Oxígeno/metabolismo , Control de Calidad , Valores de Referencia , Reproducibilidad de los Resultados
11.
Appl Microbiol Biotechnol ; 60(1-2): 67-72, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12382043

RESUMEN

Several bottlenecks in the alcoholic fermentation process must be overcome to reach a very high and competitive performance of bioethanol production by the yeast Saccharomyces cerevisiae. In this paper, a nutritional strategy is described that allowed S. cerevisiae to produce a final ethanol titre of 19% (v/v) ethanol in 45 h in a fed-batch culture at 30 degrees C. This performance was achieved by implementing exponential feeding of vitamins throughout the fermentation process. In comparison to an initial addition of a vitamin cocktail, an increase in the amount of vitamins and an exponential vitamin feeding strategy improved the final ethanol titre from 126 g l(-1) to 135 g l(-1) and 147 g l(-1), respectively. A maximum instantaneous productivity of 9.5 g l(-1) h(-1) was reached in the best fermentation. These performances resulted from improvements in growth, the specific ethanol production rate, and the concentration of viable cells in response to the nutritional strategy.


Asunto(s)
Etanol/metabolismo , Glucosa/metabolismo , Saccharomyces cerevisiae/metabolismo , Vitaminas/farmacología , Biomasa , Medios de Cultivo/metabolismo , Fermentación , Microbiología Industrial/métodos , Cinética , Saccharomyces cerevisiae/efectos de los fármacos , Coloración y Etiquetado
12.
Water Sci Technol ; 44(2-3): 437-44, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11548016

RESUMEN

With new EC regulations, alternative treatment and disposal techniques of the excess sludge produced by activated sludge wastewater treatment plants have to be developed. To decrease activated sludge production yield, microbial cell lysis can be amplified to enhance cryptic growth (biomass growth on lysates). Cell breakage techniques (thermal, alkaline and a combination) were studied to generate Ralstonia eutropha (strain model) and waste activated sludge lysates and to evaluate their biodegradability. Gentle treatment conditions by alkaline waste treatment (20 min at 60 degrees C and pH 10 by NaOH addition) allowed waste activated sludge to be solubilized by a two step process (instantaneous and post-treatment) giving a dissolved organic carbon released by the total suspended solids treated of 267 mgDOC x g(-1)TSS. The biodegradation of the soluble fraction of the lysates by fresh sludge reached 75 and 90% after 48 and 350 hrs of incubation respectively. A validation on a laboratory scale by insertion of a liquor alkaline heat treatment loop in a biological synthetic wastewater treatment process was carried out. A reduction of 37% of the excess sludge was obtained without altering the purification yield of the process.


Asunto(s)
Cupriavidus necator/fisiología , Aguas del Alcantarillado , Eliminación de Residuos Líquidos/métodos , Biodegradación Ambiental , Biomasa , Calor , Concentración de Iones de Hidrógeno , Dinámica Poblacional , Solubilidad
13.
Enzyme Microb Technol ; 27(8): 619-625, 2000 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-11024526

RESUMEN

In submerged cultures performed in synthetic medium containing glucose and glutamate, the filamentous fungus Monascus ruber produced a red pigment and a mycotoxin, citrinin. In oxygen-limiting conditions, the production of these two metabolites was growth-associated, as was the production of primary metabolites. In oxygen-excess conditions, the profile of citrinin production was typical of a secondary metabolite, since it was produced mostly during the stationary phase. In contrast, the production of the pigment decreased rapidly throughout the culture, showing a profile characteristic of an inhibitory mechanism. The organic acids produced during the culture, L-malate and succinate, were shown to be slightly inhibitory against pigment production, while citrinin production was unaffected. However, this inhibition could not account for the observed profile of pigment production in batch cultures. Other dicarboxylic acids such as fumarate or tartrate showed a similar effect to that provoked by malate and succinate as regards pigment production. It was concluded that the decrease in red pigment production during the culture was due to the inhibitory effect of an unknown product whose accumulation was favored in aerobic conditions.

14.
Int J Food Microbiol ; 55(1-3): 33-40, 2000 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-10791714

RESUMEN

Strains of Saccharomyces cerevisiae deleted for TPS1 encoding trehalose-6-phosphate synthase still accumulate trehalose when harbouring a functional MAL locus. We demonstrate that this accumulation results from an active uptake of trehalose present in the 'yeast extract' used to make the enriched culture media and that no accumulation is observed in mineral media. The uptake of trehalose was shown to be mediated by the alpha-glucoside transporter encoded by AGT1, the expression of which is linked to the presence of a functional MAL locus. Deletion of this gene in a MAL+ tps1 mutant abolished trehalose accumulation on a maltose or galactose mineral medium. However, small amounts of disaccharide were still detected in a agt1 tps1 double mutant when the medium was supplemented with 10 g trehalose l(-1), indicating the existence of a non-concentrative low-affinity sugar transporter. The presence of the high-affinity trehalose permease allowed us to investigate the effect of increasing exogenous trehalose from 0 to 10 g(-1) on intracellular accumulation. A maximum of ca. 10% (wt/wt dry cells) trehalose was attained in the presence of only 1 g l(-1) of disaccharide in the medium. The capability to monitor the intracellular content of trehalose by varying its extracellular concentration, independent of genetic alterations of the trehalose metabolic machinery, allowed the remarkable contribution of this molecule in stress tolerance to be demonstrated, as the higher the trehalose content, the longer the cell survival to a severe heat shock and to glucose starvation.


Asunto(s)
Proteínas de Transporte de Monosacáridos , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Simportadores , Trehalosa/metabolismo , Transporte Biológico , Proteínas Portadoras/fisiología , Medios de Cultivo , Fermentación , Proteínas Fúngicas/fisiología , Calor , Maltosa/metabolismo
15.
Appl Environ Microbiol ; 66(3): 1120-5, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10698780

RESUMEN

During submerged culture in the presence of glucose and glutamate, the filamentous fungus Monascus ruber produces water-soluble red pigments together with citrinin, a mycotoxin with nephrotoxic and hepatoxic effects on animals. Analysis of the (13)C-pigment molecules from mycelia cultivated with [1-(13)C]-, [2-(13)C]-, or [1, 2-(13)C]acetate by (13)C nuclear magnetic resonance indicated that the biosynthesis of the red pigments used both the polyketide pathway, to generate the chromophore structure, and the fatty acid synthesis pathway, to produce a medium-chain fatty acid (octanoic acid) which was then bound to the chromophore by a trans-esterification reaction. Hence, to enhance pigment production, we tried to short-circuit the de novo synthesis of medium-chain fatty acids by adding them to the culture broth. Of fatty acids with carbon chains ranging from 6 to 18 carbon atoms, only octanoic acid showed a 30 to 50% stimulation of red pigment production, by a mechanism which, in contrast to expectation, did not involve its direct trans-esterification on the chromophore backbone. However, the medium- and long-chain fatty acids tested were readily assimilated by the fungus, and in the case of fatty acids ranging from 8 to 12 carbon atoms, 30 to 40% of their initial amount transiently accumulated in the growth medium in the form of the corresponding methylketone 1 carbon unit shorter. Very interestingly, these fatty acids or their corresponding methylketones caused a strong reduction in, or even a complete inhibition of, citrinin production by M. ruber when they were added to the medium. Several data indicated that this effect could be due to the degradation of the newly synthesized citrinin (or an intermediate in the citrinin pathway) by hydrogen peroxide resulting from peroxisome proliferation induced by medium-chain fatty acids or methylketones.


Asunto(s)
Ascomicetos/metabolismo , Citrinina/biosíntesis , Ácidos Grasos/metabolismo , Glutaratos/metabolismo , Indoles/metabolismo , Pigmentos Biológicos/biosíntesis , Acetatos/metabolismo , Caprilatos/metabolismo , Isótopos de Carbono , Glucosa/metabolismo , Ácido Glutámico/metabolismo , Cetonas/metabolismo , Peroxisomas/metabolismo
16.
Appl Microbiol Biotechnol ; 51(6): 883-90, 1999 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10422234

RESUMEN

To decrease activated sludge production, microbial cell lysis can be amplified to enhance cryptic growth (biomass growth on lysates). Cell breakage techniques (thermal, alkaline, acid) were studied to generate Alcaligenes eutrophus and sludge lysates and to evaluate their biodegradability. Gentle treatment conditions produced the best results. Complete cell deactivation was obtained for temperatures higher than 55 degrees C. The release kinetics were similar for temperatures varying from 60 degrees C to 100 degrees C. A 20-min incubation was suitable for reaching 80% of the maximum releasable carbon. In thermal-chemical hydrolysis, NaOH was the most efficient for inducing cell lysis. Carbon release was a two-step process. First an immediate release occurred, which was of the same order of magnitude for A. eutrophus and sludge [100-200 mg dissolved organic C (DOC) g total suspended solids (TSS)-1], followed by a post-treatment release. The second step was virtually equivalent to the first for sludge, and weaker for A. eutrophus (< 50 mg DOC g TSS-1). The biodegradability of the soluble fraction, both the immediate and the post-treatment carbon release, was investigated. The optimal degradation yield, obtained with sludge cells, reached 55% after 48 h of incubation and 80% after 350 h. The most consistent lysis and biodegradation results occurred at pH 10 and 60 degrees C after a 20-min incubation.


Asunto(s)
Alcaligenes/crecimiento & desarrollo , Alcaligenes/metabolismo , Biomasa , Aguas del Alcantarillado/microbiología , Alcaligenes/efectos de los fármacos , Biodegradación Ambiental , Carbono/metabolismo , Concentración de Iones de Hidrógeno , Hidrólisis , Hidróxido de Sodio/farmacología , Sonicación , Temperatura , Eliminación de Residuos Líquidos
17.
Biotechnol Bioeng ; 64(4): 497-501, 1999 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-10397888

RESUMEN

The growth and metabolic behaviour of the filamentous fungus Monascus ruber were studied in submerged cultures under various aeration and agitation conditions. Improving the oxygen supply, by increasing either the air input or the agitation speed, resulted in modified metabolism: the biomass yield, the consumption of the nitrogen source (monosodium glutamate), and the production of secondary metabolites (red pigment and citrinin) all increased. However, the citrinin production increased more than that of the red pigment. In consequence, a low oxygen transfer coefficient was required to improve the red pigment/citrinin production ratio. Copyright 1999 John Wiley & Sons, Inc.

18.
J Bacteriol ; 181(12): 3830-2, 1999 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10368160

RESUMEN

The trehalose content in Saccharomyces cerevisiae can be significantly manipulated by including trehalose at an appropriate level in the growth medium. Its uptake is largely dependent on the expression of AGT1, which encodes an alpha-glucoside transporter. The trehalose found in a tps1 mutant of trehalose synthase may therefore largely reflect its uptake from the enriched medium that was employed.


Asunto(s)
Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Proteínas de Transporte de Monosacáridos , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Simportadores , Trehalosa/metabolismo , Transporte Biológico , Galactosa/metabolismo , Glucosa/metabolismo , Glucosiltransferasas/genética , Cinética , Saccharomyces cerevisiae/crecimiento & desarrollo
19.
Appl Environ Microbiol ; 65(1): 311-4, 1999 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9872798

RESUMEN

Carbon isotope distribution of [13C]citrinin from Monascus ruber incubated with [13C]acetate revealed that the biosynthesis of the toxin originated from a tetraketide, instead of a pentaketide as has been shown for Penicillium and Aspergillus species. The production of polyketide red pigments and citrinin by M. ruber may therefore be regulated at the level of the tetraketide branch point.

20.
Biotechnol Prog ; 14(2): 270-4, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9548779

RESUMEN

Among the numerous yeasts able to produce flavor compounds, several strains of Kluyveromyces species are known for the synthesis of large amounts of aromatic compounds. In particular, the accumulation of 2-phenylethyl alcohol in liquid cultures of Kluyveromyces marxianus was observed after incubation on a semisynthetic medium at 30 degrees C, 125 rpm. Changes in the carbon sources led to a significant modification of the amount of this aromatic compound; moreover, the variations in the level of DL-phenylalanine and the exclusive use of a precursor isomer (L) also affected the synthesis of 2-phenylethyl alcohol. Finally, this study revealed the growth inhibition of K. marxianus when the concentration of 2-phenylethyl alcohol reached a critical value near 1.4 g/L; the use of an exponential model allowed the inhibition constant ki to be determined (ki = 0.35 g/L).


Asunto(s)
Glucosa/farmacología , Kluyveromyces/efectos de los fármacos , Fenilalanina/farmacología , Alcohol Feniletílico/metabolismo , Carbono/química , Medios de Cultivo , Kluyveromyces/metabolismo , Modelos Lineales , Estereoisomerismo
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