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1.
Med Intensiva ; 41(1): 28-37, 2017.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-28029501

RESUMO

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.


Assuntos
Mortalidade Hospitalar/tendências , Unidades de Terapia Intensiva/estatística & dados numéricos , Pacotes de Assistência ao Paciente , Sepse/mortalidade , APACHE , Idoso , Idoso de 80 Anos ou mais , Feminino , Fidelidade a Diretrizes , Promoção da Saúde , Hospitais Universitários/estatística & dados numéricos , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Guias de Prática Clínica como Assunto , Avaliação de Programas e Projetos de Saúde , Estudos Prospectivos , Sepse/complicações , Choque Séptico/complicações , Choque Séptico/mortalidade , Espanha/epidemiologia , Centros de Atenção Terciária/estatística & dados numéricos
2.
Bioprocess Biosyst Eng ; 32(4): 459-66, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18923846

RESUMO

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.


Assuntos
Reatores Biológicos/microbiologia , Etanol/metabolismo , Etanol/farmacologia , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/fisiologia , Engenharia Biomédica , Fermentação , Cinética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Estresse Fisiológico
3.
Bone Marrow Transplant ; 51(2): 227-31, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26524264

RESUMO

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.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Neuroblastoma , Transplante de Células-Tronco , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Autoenxertos , Bussulfano/administração & dosagem , Bussulfano/efeitos adversos , Criança , Pré-Escolar , Intervalo Livre de Doença , Feminino , Humanos , Lactente , Masculino , Melfalan/administração & dosagem , Melfalan/efeitos adversos , Neuroblastoma/mortalidade , Neuroblastoma/terapia , Estudos Retrospectivos , Taxa de Sobrevida , Tiotepa/administração & dosagem , Tiotepa/efeitos adversos
4.
Bone Marrow Transplant ; 51(8): 1076-81, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27042850

RESUMO

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.


Assuntos
Bussulfano/administração & dosagem , Melfalan/administração & dosagem , Neuroblastoma/terapia , Adolescente , Transplante de Medula Óssea/métodos , Bussulfano/toxicidade , Criança , Pré-Escolar , Estudos de Coortes , Terapia Combinada , Feminino , Humanos , Lactente , Masculino , Melfalan/toxicidade , Neuroblastoma/complicações , Neuroblastoma/mortalidade , Transplante de Células-Tronco de Sangue Periférico/métodos , Transplante de Células-Tronco de Sangue Periférico/mortalidade , Estudos Retrospectivos , Fatores de Risco , Análise de Sobrevida
5.
Bone Marrow Transplant ; 50(8): 1083-8, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26030048

RESUMO

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.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Quimiorradioterapia/métodos , Sarcoma de Ewing/mortalidade , Sarcoma de Ewing/terapia , Adolescente , Adulto , Criança , Pré-Escolar , Intervalo Livre de Doença , Doxorrubicina/administração & dosagem , Etoposídeo/administração & dosagem , Feminino , Seguimentos , Humanos , Ifosfamida/administração & dosagem , Masculino , Taxa de Sobrevida , Tiotepa/administração & dosagem , Vincristina/administração & dosagem , Adulto Jovem
6.
Biotechnol Adv ; 7(1): 1-14, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-14542171

RESUMO

Oxygen transfer is one of the bottlenecks in conventional fermentation technology and it has so far been almost totally overlooked with regards to high cell densities and immobilized cells. This review presents some new concepts to improve oxygen supply in aerobic fermentations, especially the use of oxygen-vectors. The oxygen-vectors generally used are liquids which are insoluble in the fermentation media. Their utilization in an emulsified form can significantly increase the oxygen transfer coefficient between gas and aqueous phases. It seems that the vector acts as an active intermediate in the oxygen transport from gas bubbles to aqueous phase, but the mechanisms involved in this unconventional technique of aeration are not yet known.

7.
Appl Environ Microbiol ; 65(1): 311-4, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9872798

RESUMO

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.

8.
Biotechnol Bioeng ; 64(4): 497-501, 1999 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-10397888

RESUMO

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.

9.
Biotechnol Prog ; 14(2): 270-4, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9548779

RESUMO

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).


Assuntos
Glucose/farmacologia , Kluyveromyces/efeitos dos fármacos , Fenilalanina/farmacologia , Álcool Feniletílico/metabolismo , Carbono/química , Meios de Cultura , Kluyveromyces/metabolismo , Modelos Lineares , Estereoisomerismo
10.
Int J Food Microbiol ; 55(1-3): 33-40, 2000 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-10791714

RESUMO

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.


Assuntos
Proteínas de Transporte de Monossacarídeos , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Simportadores , Trealose/metabolismo , Transporte Biológico , Proteínas de Transporte/fisiologia , Meios de Cultura , Fermentação , Proteínas Fúngicas/fisiologia , Temperatura Alta , Maltose/metabolismo
11.
Int J Food Microbiol ; 27(2-3): 201-13, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8579990

RESUMO

Following our investigations on red pigments and monascidin co-production by Monascus species, the antibiotic called monascidin A was characterized as citrinin. Evidence was given by qualitative methods, mass spectra and NMR. Citrinin, a nephrotoxic agent was produced both by Monascus purpureus and Monascus ruber, either in submerged culture of concentrations of 270 and 340 mg/l, respectively, or in solid state culture of concentration of 100 and 300 mg/kg dried matter, respectively. Since citrinin is a toxic product, it is essential that the production of red pigments as food additives from Monascus spp. avoid the occurrence of citrinin.


Assuntos
Bactérias/efeitos dos fármacos , Citrinina/química , Citrinina/farmacologia , Proteínas Fúngicas/biossíntese , Fungos/metabolismo , Citrinina/biossíntese , Proteínas Fúngicas/farmacologia , Pigmentos Biológicos
12.
Water Sci Technol ; 44(2-3): 437-44, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11548016

RESUMO

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.


Assuntos
Cupriavidus necator/fisiologia , Esgotos , Eliminação de Resíduos Líquidos/métodos , Biodegradação Ambiental , Biomassa , Temperatura Alta , Concentração de Íons de Hidrogênio , Dinâmica Populacional , Solubilidade
13.
Bull Soc Pathol Exot ; 87(5): 312-4, 1994.
Artigo em Francês | MEDLINE | ID: mdl-7496191

RESUMO

A 26 year old woman, living in Brazzaville, was referred by her ophthalmologist about papillo-oedema. Neurological examination showed frontal syndrome and papillo-oedema without another sign of intracranial hypertension. Electroencephalogram revealed bilateral delta waves and bifrontal points. Significant inflammatory syndrome was noted. Cerebrospinal fluid examination showed trypanosomes with an elevated rate of protein and cells. Treatment by tetracosactide and eflornithine gave a good recovery. Authors are stressing the disconcerting feature of this clinical form. An urban from of the disease and the fight against african trypanosomiasis are also discussed.


Assuntos
Meningoencefalite/parasitologia , Papiledema/parasitologia , Trypanosoma brucei gambiense , Tripanossomíase Africana/diagnóstico , Adulto , Animais , Congo , Cosintropina/uso terapêutico , Ritmo Delta , Eflornitina/uso terapêutico , Eletroencefalografia , Feminino , Humanos , Meningoencefalite/líquido cefalorraquidiano , Meningoencefalite/tratamento farmacológico , Exame Neurológico , Papiledema/líquido cefalorraquidiano , Papiledema/tratamento farmacológico , Tripanossomicidas/uso terapêutico , Tripanossomíase Africana/líquido cefalorraquidiano , Tripanossomíase Africana/tratamento farmacológico
14.
Environ Technol ; 24(8): 979-87, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-14509389

RESUMO

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.


Assuntos
Esgotos/microbiologia , Eliminação de Resíduos Líquidos/métodos , Biodegradação Ambiental , Compostos Orgânicos/metabolismo , Oxigênio/metabolismo , Controle de Qualidade , Valores de Referência , Reprodutibilidade dos Testes
15.
Med. intensiva (Madr., Ed. impr.) ; 41(1): 28-37, ene.-feb. 2017. graf, tab
Artigo em Inglês | IBECS (Espanha) | ID: ibc-160093

RESUMO

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


Assuntos
Humanos , Sepse/mortalidade , Choque Séptico/mortalidade , Unidades de Terapia Intensiva/estatística & dados numéricos , Avaliação de Processos e Resultados em Cuidados de Saúde , Mortalidade/tendências , Cuidados Críticos/estatística & dados numéricos , Estudos de Coortes
17.
Bioprocess Biosyst Eng ; 28(1): 55-61, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16195896

RESUMO

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.


Assuntos
Reatores Biológicos/microbiologia , Técnicas de Cultura de Células/métodos , Glucose/metabolismo , Modelos Biológicos , Espiramicina/biossíntese , Streptomyces/crescimento & desenvolvimento , Streptomyces/metabolismo , Biomassa , Proliferação de Células , Simulação por Computador , Especificidade da Espécie , Streptomyces/classificação
18.
Biotechnol Bioeng ; 24(7): 1565-79, 1982 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18546457

RESUMO

The ideal method to produce a terminal metabolite inhibitor of cell growth and production is to remove and recover it from the fermenting broth as it formed. Extractive fermentation is achieved in the case of ethanol production by coupling both fermentation and liquid-liquid extraction, The solvent of extraction is 1-dodecanol (or a mixture 1-dedecanol, 1-tetradecanol); study of the inhibitory effect of primary aliphatic alcohols of different chain lengths shows that no growth is observed in the presence of alcohols which have between 2 and 12 carbons. This effect is suppressed when the carbon number is 12 or higher. A new reactor has been used-1 pulsed packed column. Pulsation is performed pneumatically. Porous material used as a package adsorbs the cells. The fermentation broth is pulsed in order to (1) increase the interfacial area between the aqueous phase and the dodecanol, (2) decrease gas holdup. Alcoholic fermentation, performed at 35 degrees C on glucose syrup, permits the total utilization of glucose solution of 409 g/L with a yeast which cannot-in classical process- completely use solutions with 200 g/L of glucose. The feasibility of a new method of fermentation coupling both liquid-liquid extraction and fermentation is demonstrated. Extension of this method is possible to any microbial production inhibited by its metabolite excretion.

19.
Biotechnol Bioeng ; 28(4): 523-33, 1986 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18555356

RESUMO

The technology of coupling ultrafiltration and fermentation has been tested with the acetonobutylic fermentation in continuous mode. The device developed was sterilizable by steam and permitted drastic cleaning of the ultrafiltration (UF) membrane without interrupting the continuous fermentation. It has been shown to be an easily operated and reliable experimental tool for studying high-cell-density cultures and inhibition phenomena. With total recycle of biomass, a dry weight concentration of 125 g/L was attained, which greatly enhanced the volumetric solvent productivity of acetonobutylic fermentation in averaging 4. 5 g/L h for significant periods of time (>70 h) and maintaining solvent concentration and yield at acceptable levels.

20.
Biotechnol Bioeng ; 26(2): 148-55, 1984 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18551701

RESUMO

Butanediol production by Aerobacter aerogenes NRRL B199 grown on glucose requires an optimal rate of aeration for the obtention of butanediol 2, 3. In the absence of air, Aerobacter aerogenes NRRL B199 growth and production are weak. Agitation-aeration is necessary for producing the biomass, but an excess of oxygen proves to be toxic with regard to metabolite production. Oxygen is a limiting substrate with regard to growth and an inhibitor with regard to the specific metabolite productivity. This observation is discussed from a kinetic stand point and in relation to the search for the optimum oxygen transfer coefficient (K(L)a), which is found to be in the range of 50-100h(-1). It has also been observed that K(L)a increases during the fermentation cycle. The initial substrate concentration effects the yield production of biomass and butanediol production. Low yields of butanediol are obtained at low initial sugar concentrations, but good yields of butanediol are obtained (0.45 g/g) at high concentrations of glucose (195 g/L). Carbon substrates and butanediol are inhibitors of cell growth while butanediol is not quite an inhibitor of the specific rate of butanediol production for the range of butanediol of 0-100 g/L.

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