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1.
J Vasc Bras ; 23: e20230094, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39099701

RESUMEN

Extracranial cerebrovascular disease has been the subject of intense research throughout the world, and is of paramount importance for vascular surgeons. This guideline, written by the Brazilian Society of Angiology and Vascular Surgery (SBACV), supersedes the 2015 guideline. Non-atherosclerotic carotid artery diseases were not included in this document. The purpose of this guideline is to bring together the most robust evidence in this area in order to help specialists in the treatment decision-making process. The AGREE II methodology and the European Society of Cardiology system were used for recommendations and levels of evidence. The recommendations were graded from I to III, and levels of evidence were classified as A, B, or C. This guideline is divided into 11 chapters dealing with the various aspects of extracranial cerebrovascular disease: diagnosis, treatments and complications, based on up-to-date knowledge and the recommendations proposed by SBACV.

2.
J. Vasc. Bras. (Online) ; J. vasc. bras;23: e20230094, 2024. tab, graf
Artículo en Portugués | LILACS-Express | LILACS | ID: biblio-1558346

RESUMEN

Resumo A doença cerebrovascular extracraniana tem sido intensamente investigada em todo o mundo, sendo tema de suma importância para os cirurgiões vasculares. A presente Diretriz foi elaborada pela Sociedade Brasileira de Angiologia e Cirurgia Vascular (SBACV) em sucessão à Diretriz de 2015. As doenças de etiologia não ateroscleróticas não foram incluídas nesse documento. O objetivo desta Diretriz é congregar as evidências mais robustas nessa área para auxiliar os especialistas no processo decisório do tratamento. Foi utilizada a metodologia AGREE II e o sistema da Sociedade Europeia de Cardiologia para as recomendações e níveis de evidências. As recomendações foram graduadas de I a III, e os níveis de evidência classificados em A, B e C. A presente Diretriz foi dividida em 11 capítulos, que tratam dos vários aspectos da doença cerebrovascular extracraniana: diagnóstico, tratamentos e complicações, de forma atualizada e com as recomendações propostas pela SBACV.


Abstract Extracranial cerebrovascular disease has been the subject of intense research throughout the world, and is of paramount importance for vascular surgeons. This guideline, written by the Brazilian Society of Angiology and Vascular Surgery (SBACV), supersedes the 2015 guideline. Non-atherosclerotic carotid artery diseases were not included in this document. The purpose of this guideline is to bring together the most robust evidence in this area in order to help specialists in the treatment decision-making process. The AGREE II methodology and the European Society of Cardiology system were used for recommendations and levels of evidence. The recommendations were graded from I to III, and levels of evidence were classified as A, B, or C. This guideline is divided into 11 chapters dealing with the various aspects of extracranial cerebrovascular disease: diagnosis, treatments and complications, based on up-to-date knowledge and the recommendations proposed by SBACV.

3.
Rev. bras. cir. cardiovasc ; Rev. bras. cir. cardiovasc;37(5): 622-627, Sept.-Oct. 2022. tab
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1407282

RESUMEN

ABSTRACT Introduction: Although endovascular correction is a promising perspective, the gold-standard treatment for thoracoabdominal aortic aneurisms and type-B dissections with visceral involvement remains open surgery, particularly due to its well-established long-term durability. This study aims to describe and evaluate public data from patients treated for thoracoabdominal aortic aneurism in the Brazilian public health system in a 12-year interval. Methods: Data from procedures performed between 2008 and 2019 were extracted from the national public database (Departamento de Informática do Sistema Único de Saúde, or DATASUS) using web scraping techniques. Procedures were evaluated regarding the yearly frequency of elective or urgency surgeries, in-hospital mortality, and governmental costs. All tests were done with a level of significance P<0.05. Results: A total of 812 procedures were analyzed. Of all surgeries, 67.98% were elective cases. There were 328 in-hospital deaths (mortality of 40.39%). In-hospital mortality was lower in elective procedures (26.92%) than in urgency procedures (46.74%) (P=0.008). Total governmental expenditure was $3.127.051,56 — an average of $3.774,22 for elective surgery and $3.791,93 for emergency surgery (P=0.999). Conclusion: The proportion of urgency procedures is higher than that recommended by international literature. Mortality was higher for urgent admissions, although governmental costs were equal for elective and urgent procedures; specialized referral centers should be considered by health policy makers.

4.
Braz J Cardiovasc Surg ; 37(5): 622-627, 2022 10 08.
Artículo en Inglés | MEDLINE | ID: mdl-35657309

RESUMEN

INTRODUCTION: Although endovascular correction is a promising perspective, the gold-standard treatment for thoracoabdominal aortic aneurisms and type-B dissections with visceral involvement remains open surgery, particularly due to its well-established long-term durability. This study aims to describe and evaluate public data from patients treated for thoracoabdominal aortic aneurism in the Brazilian public health system in a 12-year interval. METHODS: Data from procedures performed between 2008 and 2019 were extracted from the national public database (Departamento de Informática do Sistema Único de Saúde, or DATASUS) using web scraping techniques. Procedures were evaluated regarding the yearly frequency of elective or urgency surgeries, in-hospital mortality, and governmental costs. All tests were done with a level of significance P<0.05. RESULTS: A total of 812 procedures were analyzed. Of all surgeries, 67.98% were elective cases. There were 328 in-hospital deaths (mortality of 40.39%). In-hospital mortality was lower in elective procedures (26.92%) than in urgency procedures (46.74%) (P=0.008). Total governmental expenditure was $3.127.051,56 - an average of $3.774,22 for elective surgery and $3.791,93 for emergency surgery (P=0.999). CONCLUSION: The proportion of urgency procedures is higher than that recommended by international literature. Mortality was higher for urgent admissions, although governmental costs were equal for elective and urgent procedures; specialized referral centers should be considered by health policy makers.


Asunto(s)
Aneurisma de la Aorta Torácica , Disección Aórtica , Implantación de Prótesis Vascular , Procedimientos Endovasculares , Humanos , Aneurisma de la Aorta Torácica/cirugía , Aneurisma de la Aorta Torácica/etiología , Disección Aórtica/cirugía , Implantación de Prótesis Vascular/métodos , Salud Pública , Brasil/epidemiología , Procedimientos Endovasculares/métodos , Resultado del Tratamiento , Estudios Retrospectivos , Complicaciones Posoperatorias/etiología
5.
Einstein (Sao Paulo) ; 20: eAO6724, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35352768

RESUMEN

OBJECTIVE: Despite the development of endovascular procedures, open repair remains the gold standard for the treatment of aortic thoracoabdominal aneurysms and some type B dissections, with well-established good outcomes and long-term durability at high-volume centers. The present study described and analyzed public data from patients treated in the public system in a 12-year interval, in a city where more than 5 million inhabitants depend on the Public Health System. METHODS: Public data from procedures performed between 2008 and 2019 were extracted using web scraping techniques. The variables available in the database include sex, age, elective or emergency hospital admission, number of surgeries, in-hospital mortality, length of stay, and information on reimbursement values. RESULTS: A total of 556 procedures were analyzed. Of these, 60.79% patients were men, and 41.18% were 65 years of age or older. Approximately 60% had a residential address registered in the municipality. Of all surgeries, 65.83% were elective cases. There were 178 in-hospital deaths (mortality of 32%). In the elective context, there were 98 deaths 26.78% versus 80 deaths (42.10%) in the emergency context (p=0.174). Mortality was lower in the hospitals that performed more surgeries. A total of USD 3,038,753.92 was paid, an average of USD 5,406.95 for elective surgery and USD 5,074.76 for emergency surgery (p=0.536). CONCLUSION: Mortality was no different between groups, and hospitals with higher volume presented more favorable outcomes. Specialized referral centers should be considered by health policy makers.


Asunto(s)
Aneurisma de la Aorta Abdominal , Aneurisma de la Aorta Torácica , Aneurisma de la Aorta Abdominal/cirugía , Aneurisma de la Aorta Torácica/epidemiología , Aneurisma de la Aorta Torácica/cirugía , Brasil/epidemiología , Humanos , Tiempo de Internación , Masculino , Salud Pública
6.
Einstein (São Paulo, Online) ; 20: eAO6724, 2022. tab
Artículo en Inglés | LILACS | ID: biblio-1364793

RESUMEN

ABSTRACT Objective Despite the development of endovascular procedures, open repair remains the gold standard for the treatment of aortic thoracoabdominal aneurysms and some type B dissections, with well-established good outcomes and long-term durability at high-volume centers. The present study described and analyzed public data from patients treated in the public system in a 12-year interval, in a city where more than 5 million inhabitants depend on the Public Health System. Methods Public data from procedures performed between 2008 and 2019 were extracted using web scraping techniques. The variables available in the database include sex, age, elective or emergency hospital admission, number of surgeries, in-hospital mortality, length of stay, and information on reimbursement values. Results A total of 556 procedures were analyzed. Of these, 60.79% patients were men, and 41.18% were 65 years of age or older. Approximately 60% had a residential address registered in the municipality. Of all surgeries, 65.83% were elective cases. There were 178 in-hospital deaths (mortality of 32%). In the elective context, there were 98 deaths 26.78% versus 80 deaths (42.10%) in the emergency context (p=0.174). Mortality was lower in the hospitals that performed more surgeries. A total of USD 3,038,753.92 was paid, an average of USD 5,406.95 for elective surgery and USD 5,074.76 for emergency surgery (p=0.536). Conclusion Mortality was no different between groups, and hospitals with higher volume presented more favorable outcomes. Specialized referral centers should be considered by health policy makers.


Asunto(s)
Humanos , Masculino , Aneurisma de la Aorta Torácica/cirugía , Aneurisma de la Aorta Torácica/epidemiología , Aneurisma de la Aorta Abdominal/cirugía , Brasil/epidemiología , Salud Pública , Tiempo de Internación
7.
J Environ Manage ; 285: 112134, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33588162

RESUMEN

Pollution due to waste generated by the oil industry has led to serious damage to ecosystems and the environment. Therefore, preventive and corrective actions must be taken to mitigate the ecological impact of waste resulting from oil-related activities, to explore and implement environment-friendly approaches, and achieve sustainable development. In this study, an alternative treatment for cuttings generated during the drilling of oil wells was investigated by extracting the hydrocarbons present in such cuttings through the use of carbon dioxide under supercritical conditions. The extractions were performed in a Supercritical Fluid Technologies Inc. Model SFT-150 extractor, under varying pressure (2300-6600 psi) and temperature (52-109 °C), while maintaining constant carbon dioxide flow rate and extraction time, to analyse the effect of these two thermodynamic variables on the extraction efficiency. During supercritical extraction, 21.51 g of total hydrocarbons from drill cuttings (oil/kg) were recovered at 6000 psi and 100 °C. The results indicated that pressure had the strongest effect on the extraction yield, with only a small amount of hydrocarbons recovered at the lowest pressure for all fractions. At <3000 psi pressure, increasing the temperature led to a decrease in the amount of recovered hydrocarbons; at >3000 psi pressure, increasing the temperature led to an increase in the extraction yield.


Asunto(s)
Dióxido de Carbono , Ecosistema , Hidrocarburos , Yacimiento de Petróleo y Gas , Temperatura
8.
Eur J Cardiothorac Surg ; 59(1): 276-277, 2021 01 04.
Artículo en Inglés | MEDLINE | ID: mdl-32840317

RESUMEN

Superior vena cava aneurysms are rare mediastinal vascular lesions. Aneurysms are classified as fusiform and saccular, with the latter being rarer than the former. We report the case of an asymptomatic 75-year-old woman who presented with a superior mediastinal mass. She underwent chest computed tomography angiography, which demonstrated a saccular aneurysm in the superior vena cava.


Asunto(s)
Aneurisma , Enfermedades del Mediastino , Anciano , Aneurisma/diagnóstico por imagen , Aneurisma/cirugía , Femenino , Humanos , Mediastino/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Vena Cava Superior/diagnóstico por imagen
9.
Chemosphere ; 259: 127418, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32574848

RESUMEN

This work evaluated the effect of different initial biomass ratios in a co-culture of an alkaliphilic methanotrophic bacteria consortium (AMB) and the green microalga Scenedesmus obtusiusculus (GM) on the maximum CH4 specific biodegradation rate and global carbon uptake. The highest maximum specific biodegradation rate was 589 ± 0.01 mgCH4 gbiomass-1 d-1 obtained for a proportion of 3:1 AMB-GM (w w-1) and 8% of initial CH4 in the headspace. The methane degradation rate was 1.5 times lower than the value obtained solely by the AMB consortium, and it was associated with pH increases due to the evolved CO2 consumption by the microalga. Increased activity of the AMB consortium along the experiments was due to progressive adaptation. Massive sequencing revealed the presence of methanotrophic/methylotrophic species such as Methylocystis sp., Methylomicrobium sp., Methylophaga sp., and Hyphomicrobium sp. Successful complete methane and carbon dioxide uptake was obtained with the 3:1, 4:1, and 5:1 AMB-GM biomass ratios, while for the rest of the ratios tested, more than 70% of the initial methane was transformed into biomass and inorganic carbon. This study showed that methanotrophic-microalgal co-cultures lead to a promising strategy for greenhouse gases mitigation in one step.


Asunto(s)
Biodegradación Ambiental , Gases de Efecto Invernadero , Metano/metabolismo , Microalgas/fisiología , Biomasa , Dióxido de Carbono/metabolismo , Técnicas de Cocultivo , Methylocystaceae , Microalgas/metabolismo , Scenedesmus/metabolismo
10.
Environ Sci Pollut Res Int ; 27(23): 28561-28574, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32130637

RESUMEN

The microalga Scenedesmus obtusiusculus AT-UAM efficiently captured CO2 from two flue gas streams in a hybrid photobioreactor located in a greenhouse. Uptake rates of CO2, NO, and SO2 from a formulated gas stream were 160.7 mg L-1 day-1, 0.73 mg L-1 day-1, and 1.56 mg L-1 day-1, respectively, with removal efficiencies of 100% for all gases. Exhaust gases of a motor generator were also removed with uptake rates of 111.4 mg L-1 day-1, 0.42 mg L-1 day-1, and 0.98 mg L-1 day-1, obtaining removal efficiencies of 77%, 71%, and 53% for CO2, NOx, and SO2, respectively. On average, 61% of the CO2 from both flue gas streams was assimilated as microalgal biomass. The maximum CO2 uptake rate of 182 mg L-1 day-1 was achieved for formulated flue gas flow rate above 100 mL min-1. The biomass recovery of 88% was achieved using a 20-L electro-coagulation-flotation chamber coupled to a settler with a low specific power consumption of 0.27 kWh kg-1. The photobioreactor was operated for almost 7 months without contamination of invasive species or a decrease in the activity. It is a very encouraging result for long-term operation in flue gas treatment.


Asunto(s)
Microalgas , Scenedesmus , Biomasa , Dióxido de Carbono , Gases , Fotobiorreactores
11.
FEMS Microbiol Lett ; 365(3)2018 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-29228188

RESUMEN

Microalgae are among the most productive biological systems for converting sunlight into chemical energy, which is used to capture and transform inorganic carbon into biomass. The efficiency of carbon dioxide capture depends on the cultivation system configuration (photobioreactors or open systems) and can vary according to the state of the algal physiology, the chemical composition of the nutrient medium, and environmental factors such as irradiance, temperature and pH. This mini-review is focused on some of the most important environmental factors determining photosynthetic activity, carbon dioxide biofixation, cell growth rate and biomass productivity by microalgae. These include carbon dioxide and O2 concentrations, light intensity, cultivation temperature and nutrients. Finally, a review of the operation of microalgal cultivation systems outdoors is presented as an example of the impact of environmental conditions on biomass productivity and carbon dioxide fixation.


Asunto(s)
Reactores Biológicos , Dióxido de Carbono/metabolismo , Ambiente , Microalgas/metabolismo , Concentración de Iones de Hidrógeno , Luz , Microalgas/crecimiento & desarrollo , Microalgas/fisiología , Nutrientes/metabolismo , Oxígeno/metabolismo , Fotosíntesis , Temperatura
12.
Biotechnol Rep (Amst) ; 17: 16-23, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29276696

RESUMEN

Scenedesmus obtusiusculus AT-UAM, isolated from Cuatro Ciénegas wetlands in Mexico was taxonomically, molecularly and biochemically compared to S. obtusiusculus CCAP 276/25 (Culture Collection of Algae and Protozoa, Scotland, UK). Analysis of Internal Transcribed Spacer 2 (ITS2) secondary structures confirmed that the mexican strain belongs to S. obtusiusculus with one change in the ITS2 nucleotide sequence. However, both strains exhibited different biochemical and fatty acid profiles and therefore biotechnological potential, emphasizing the need for deeper studies among strains of the same species. Furthermore, the biochemical variations of S. obtusiusculus AT-UAM under nitrogen starvation and different levels of irradiance were evaluated. The maximum lipid production (1730 mg L-1) was obtained at 613 µmol m-2 s-1 while the highest carbohydrate content (49%) was achieved at 896 µmol m-2 s-1. Additionally, this strain was capable of storing lipids (∼52%) and carbohydrates (∼40%) under outdoor condition depending on the light availability in the cultivation broth.

13.
Genome Announc ; 5(33)2017 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-28818899

RESUMEN

Sphingobacterium sp. CZ-UAM was isolated from a methanotrophic consortium in mineral medium using methane as the only carbon source. A draft genome of 5.84 Mb with a 40.77% G+C content is reported here. This genome sequence will allow the investigation of potential methanotrophy in this isolated strain.

14.
Sci Total Environ ; 584-585: 1310-1316, 2017 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-28187940

RESUMEN

The extensive microalgae diversity offers considerable versatility for a wide range of biotechnological applications in environmental and production processes. Microalgal cultivation is based on CO2 fixation via photosynthesis and, consequently, it is necessary to evaluate, in a short time and reliable way, the effect of the CO2 gas concentration on the consumption rate and establish the tolerance range of different strains and the amount of inorganic carbon that can be incorporated into biomass in order to establish the potential for industrial scale application. Dynamic experiments allow calculating the short-term microalgal photosynthetic activity of strains in photobioreactors. In this paper, the effect of step-changes in CO2 concentration fed to a 20L bubble column photobioreactor on the CO2 consumption rate of Scenedesmus obtusiusculus was evaluated at different operation times. The highest apparent CO2 consumption rate (336µmolm-2s-1 and 5.6% of CO2) was 6530mgCO2gb-1d-1 and it decreased to 222mgCO2gb-1d-1 when biomass concentration increased of 0.5 to 3.1gbL-1 and 5.6% of CO2 was fed. For low CO2 concentrations (<3.8%) the pH remained close to the optimal value (7.5 and 8). The CO2 consumption rates show that S. obtusiusculus was not limited by CO2 availability for concentrations above of 3.8%. The CO2 mass balance showed that 90% of the C-CO2 transferred was used for S. obtusiusculus growth.


Asunto(s)
Dióxido de Carbono/metabolismo , Fotobiorreactores , Scenedesmus/metabolismo , Biomasa , Microalgas/metabolismo
15.
Bioresour Technol ; 226: 238-246, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28011238

RESUMEN

A Rhodobacter capsulatus strain and a photoheterotrophic culture (IZT) were cultivated to produce hydrogen under different light-dark cycles. A dark fermentation effluent (DFE) was used as substrate. It was found that IZT culture had an average cumulative hydrogen production (Paccum H2) of 1300±43mLH2L-1 under continuous illumination and light-dark cycles of 30 or 60min. In contrast, R. capsulatus reduced its Paccum H2 by 20% under 30:30min light-dark cycles, but tripled its poly-ß-hydroxybutyrate (PHB) content (308±2mgPHB gdw-1) compared to continuous illumination. The highest PHB content by IZT culture was 178±10mgPHB gdw-1 under 15:15min light-dark cycles. PCR-DGGE analysis revealed that the IZT culture was mainly composed of Rhodopseudomonas palustris identified with high nucleotide similarity (99%). The evaluated cultures might be used for hydrogen and PHB production. They might provide energy savings by using light-dark cycles and DFE valorization.


Asunto(s)
Hidroxibutiratos/química , Poliésteres/química , Rhodobacter capsulatus/metabolismo , Análisis de la Demanda Biológica de Oxígeno , ADN/química , Electroforesis en Gel de Gradiente Desnaturalizante , Fermentación , Hidrógeno/química , Cinética , Luz , Nucleótidos/química , Fotoperiodo , Poliésteres/metabolismo , Rhodopseudomonas/metabolismo
16.
Bioresour Technol ; 181: 128-35, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25647022

RESUMEN

This paper evaluates the effect of the irradiance, pH and temperature on the photosynthetic activity (PA) of Scenedesmus obtusiusculus under N-replete and N-deplete conditions through oxygen measurements. The highest PA values were 160 mgO2 gb(-1) h(-1) at 620 µmol m(-2) s(-1), 35 °C and pH of 8 under N-replete conditions and 3.3 mgO2 gb(-1) h(-1) at 100 µmol m(-2) s(-1), 28.5 °C and pH of 5.5 for N-deplete conditions. Those operation conditions were tested in a flat-panel photobioreactor. The biomass productivity was 0.97 gb L(-1) d(-1) under N-replete conditions with a photosynthetic efficiency (PE) of 4.4% yielding 0.85 gb mol photon(-1). Similar biomass productivity was obtained under N-deplete condition; and the lipid productivity was 0.34 gL L(-1) d(-1) with a PE of 7.8% yielding 0.39 gL mol photon(-1). The apparent activation and deactivation energies were 16.1 and 30 kcal mol(-1), and 11.9 and 15.3 kcal mol(-1), for N-replete and N-deplete conditions, respectively.


Asunto(s)
Luz , Nitrógeno/farmacología , Fotosíntesis/efectos de los fármacos , Fotosíntesis/efectos de la radiación , Scenedesmus/fisiología , Temperatura , Biomasa , Concentración de Iones de Hidrógeno , Lípidos/biosíntesis , Estrés Oxidativo/efectos de los fármacos , Estrés Oxidativo/efectos de la radiación , Oxígeno/metabolismo , Fotobiorreactores/microbiología , Scenedesmus/efectos de los fármacos , Scenedesmus/efectos de la radiación
17.
Bioresour Technol ; 130: 652-8, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23334023

RESUMEN

An indigenous microalga was isolated from the springs in Cuatro Ciénegas, México. It was morphologically identified as Scenedesmus obtusiusculus and cultivated in bubble-column photobioreactors in batch operation mode. This microalga grows at 10% of carbon dioxide (CO(2)) showing a maximum CO(2) fixation rate of 970gm(-3)d(-1). The microalga, without any nutrient limitation, contained 20% of nonpolar lipids with a biomass productivity of 500gm(-3)d(-1) and a maximum biomass concentration of around 6,000gm(-3) at 5% CO(2) and irradiance of 134µmolm(-2)s(-1). Furthermore, it was observed that the microalga stored 55.7% of nonpolar lipids when 5% CO(2) was fed at 0.8vvm and 54.7µmolm(-2)s(-1) under nitrogen starvation. The lipid profile included C16:0, C18:0, C18:1n9t, C18:1n9c, C18:3n6 with a productivity of 200g lipid m(-3)d(-1). Therefore, the microalga may have biotechnological potential producing lipids for biodiesel.


Asunto(s)
Dióxido de Carbono/metabolismo , Metabolismo de los Lípidos , Microalgas/metabolismo , Scenedesmus/metabolismo , Aire , Ciclo del Carbono , Luz , Microalgas/crecimiento & desarrollo , Microalgas/aislamiento & purificación , Nitrógeno/metabolismo , Scenedesmus/crecimiento & desarrollo , Scenedesmus/aislamiento & purificación
18.
Bioresour Technol ; 129: 686-9, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23298771

RESUMEN

Methylobacterium organophilum CZ-2 synthesized polyhydroxyalkanoates (PHAs) under nitrogen limitation with CH4 as carbon source and when either citrate or propionate was added as cosubstrates. The highest PHAs content (yPHA) in closed flasks was obtained in the CH4-citrate and CH4-propionate experiments attaining values of 0.82 and 0.68, respectively. M. organophilum CZ-2 cultivated in bioreactors with citrate and continuous CH4 addition yielded a final PHAs concentration of 143 gm(-3) containing hydroxybutyrate (HB), hydroxyvalerate (HV) and hydroxyoctanoate (HO), in a 55:35:10 ratio, with, yPHA of 0.88 and a CH4 elimination capacity (EC) of 20 gm(-3) h(-1). With propionate, the yPHA was 0.3 and the EC around 8 gm(-3) h(-1). From 1H and 13C NMR experiments it was found that the polymer produced with CH4-citrate contained six different monomers: 3HB, 3HV, 4HV, 4-hydroxyheptanoate (4HH), 3HO and 4HO, showing the great versatility of this PHAs producing bacterium.


Asunto(s)
Ácido Cítrico/metabolismo , Metano/metabolismo , Methylobacterium/metabolismo , Polihidroxialcanoatos/biosíntesis , Polihidroxialcanoatos/aislamiento & purificación , Propionatos/metabolismo , Methylobacterium/clasificación , Especificidad de la Especie
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