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1.
Front Cardiovasc Med ; 11: 1301925, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38576420

RESUMO

Introduction: It is well-known that circulating microRNAs (miRNAs) play a relevant role in many kinds of diseases by regulating the expression of genes involved in various pathophysiologic processes, including erectile dysfunction (ED) and cardiovascular diseases (CVD). Purpose: This study aimed to identify the miRNA-21 profile in the blood samples of patients with ED, CVD, and the combination of both pathologies to elucidate the potential function of miRNA-21. Methods: A total of 45 patients with CVD and/or who underwent the erectile function test were included and divided into the following categories: CVD with ED (cases, n = 29) and controls (n = 16) with either ED or CVD. Real-time polymerase chain reaction analysis verified the results. miRNA-21 expression was quantified, and informatics analysis was applied to predict the functions of this differentially expressed miRNA-21. Results: A total of 64% of cases (63 ± 9 years, 66% with severe ED, 56% with CV ejection fraction) first presented ED as the sentinel clinical manifestation. Serum miRNA-21 levels in the control ED were significant, up to 10-fold higher than in the CVD controls and cases. A significant inverse (p = 0.0368, ß = -2.046) correlation was found between erectile function and miRNA-21 levels. Conclusions: Our study provides comprehensive insights into the functional interaction between miRNA-21 and ED in CVD patients. Its relevance lies in the potential of miRNA as a biomarker to be applied in the cardiovascular predictive medicine field.

2.
Microb Biotechnol ; 17(3): e14434, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38465780

RESUMO

Our planet, which operates as a closed system, is facing increasing entropy due to human activities such as the overexploitation of natural resources and fossil fuel use. The COP28 in Dubai emphasized the urgency to abandon fossil fuels, recognizing them as the primary cause of human-induced environmental changes, while highlighting the need to transition to renewable energies. We promote the crucial role of microbes for sustaining biogenic cycles to combat climate change and the economic potential of synthetic biology tools for producing diverse non-fossil fuels and chemicals, thus contributing to emission reduction in transport and industry. The shift to 'green chemistry' encounters challenges, derived from the availability of non-food residues and waste (mainly lignocellulosic) as raw material, the construction of cost-effective bioprocessing plants, product recovery from fermentation broths and the utilization of leftover lignin residues for synthesizing new chemicals, aligning with circular economy and sustainable development goals. To meet the Paris Agreement goals, an urgent global shift to low-carbon, renewable sources is imperative, ultimately leading to the cessation of our reliance on fossil fuels.


Assuntos
Combustíveis Fósseis , Desenvolvimento Sustentável , Humanos , Energia Renovável , Recursos Naturais , Biotecnologia
3.
Tex Heart Inst J ; 51(1)2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38345902

RESUMO

OBJECTIVE: The purpose of this study was to apply contemporary consensus criteria developed by the Society for Cardiovascular Pathology and the Association for European Cardiovascular Pathology to the evaluation of aortic pathology, with the expectation that the additional pathologic information may enhance the understanding and management of aortic diseases. METHODS: A scoring system was applied to ascending aortic specimens from 42 patients with heritable thoracic aortic disease and known genetic variations and from 86 patients from a single year, including patients with known genetic variations (n = 12) and patients with sporadic disease (n = 74). RESULTS: The various types of lesions of medial degeneration and the overall severity of medial degeneration overlapped considerably between those patients with heritable disease and those with sporadic disease; however, patients with heritable thoracic aortic disease had significantly more overall medial degeneration (P = .004) and higher levels of elastic fiber fragmentation (P = .03) and mucoid extracellular matrix accumulation (P = .04) than patients with sporadic thoracic aortic disease. Heritable thoracic aortic disease with known genetic variation was more prevalent in women than in men (27.2% vs 9.8%; P = .04), and women had more severe medial degeneration than men (P = .04). Medial degeneration scores were significantly lower for patients with bicuspid aortic valves than for patients with tricuspid aortic valves (P = .03). CONCLUSION: The study's findings indicate considerable overlap in the pattern, extent, and severity of medial degeneration between sporadic and hereditary types of thoracic aortic disease. This finding suggests that histopathologic medial degeneration represents the final common outcome of diverse pathogenetic factors and mechanisms.


Assuntos
Aneurisma da Aorta Torácica , Doenças da Aorta , Masculino , Humanos , Feminino , Aneurisma da Aorta Torácica/diagnóstico , Aneurisma da Aorta Torácica/genética , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/patologia , Aorta
4.
Int J Med Inform ; 180: 105269, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37907015

RESUMO

INTRODUCTION: Technology Enhanced Learning (TEL) can provide the tools to safely master minimally invasive surgery (MIS) skills in patient-free environments and receive immediate objective feedback without the constant presence of an instructor. However, TEL-based systems tend to work isolated from one another, focus on different skills, and fail to provide contents without a sound pedagogical background. OBJECTIVE: The objective of this descriptive study is to present in detail EASIER, an innovative TEL platform for surgical and interventional training, as well as the results of its validation. METHODS: EASIER provides a Learning Management System (LMS) for institutions and content creators that can connect and integrate TEL "external assets" (virtual reality simulators, augmented box trainers, augmented videos, etc.) addressing different skills. The platform integrates all skills under an Assessment Module that measures skills' progress in different courses. Finally, it provides content creators with a pedagogical model to scaffold contents while retaining flexibility to approach course design with different training philosophies in mind. Three courses were developed and hosted in the platform to validate it with end-users in terms of usability, performance, learning results in the courses and student self-perception on learning. RESULTS: In total 111 volunteers completed the validation. The study was limited due to the COVID-19 pandemic, which limited access to external assets (virtual reality simulators). Nevertheless, usability was rated with 73.1 in the System Usability Scale. Most positive aspects on performance were easiness to access the platform, easiness to change the configuration and not requiring additional plug-ins to use the platform. The platform was rated above average in the six scales of the User Experience Questionnaire. Overall, student results improved significantly across the three courses (p < 0.05). CONCLUSIONS: This study provides, within its limitations, evidence on the usefulness of the EASIER platform for distance learning of MIS skills. Results show the potential impact of the platform and are an encouraging boost for the future, especially in the aftermath of the COVID-19 pandemic.


Assuntos
Educação a Distância , Procedimentos Cirúrgicos Minimamente Invasivos , Humanos , Competência Clínica , COVID-19 , Aprendizagem , Procedimentos Cirúrgicos Minimamente Invasivos/educação , Pandemias
5.
Front Microbiol ; 14: 1205860, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37577419

RESUMO

Although there is some evidence to suggest that LuxR-solo proteins participate in inter-species or even inter-kingdom communication, most of the LuxR-solo protein functions are unknown. We have characterized the LuxR402 regulator of Novosphingobium sp. HR1a, a bacterial strain with the ability to establish high numbers in the plant rhizosphere and able to degrade a wide range of polycyclic aromatic hydrocarbons. LuxR402 controls the aggregation state of the bacterial culture; cultures of a mutant strain lacking this regulator flocculate in less than 3 h without agitation. We have demonstrated that the bacterial surface of the mutant is highly hydrophobic and that the mutant cells assimilate sugars slower than the wild-type. The flocculation mechanism has been demonstrated to be involved in the survival of the strain under unfavorable conditions; the luxR402 gene is repressed and produces flocculation in the presence of salicylate, a substrate that, although being assimilated by Novosphingobium, is toxic to cells at high concentrations. The flocculation of cultures in industrial setups has mainly been achieved through the addition of chemicals; these studies open up the possibility of controlling the flocculation by regulating the level of expression of the luxR402 gene.

6.
Heliyon ; 9(6): e16692, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37484356

RESUMO

Most worldwide policy frameworks, including the United Nations Sustainable Development Goals, highlight soil as a key non-renewable natural resource which should be rigorously preserved to achieve long-term global sustainability. Although some soil is naturally enriched with heavy metals (HMs), a series of anthropogenic activities are known to contribute to their redistribution, which may entail potentially harmful environmental and/or human health effects if certain concentrations are exceeded. If this occurs, the implementation of rehabilitation strategies is highly recommended. Although there are many publications dealing with the elimination of HMs using different methodologies, most of those works have been done in laboratories and there are not many comprehensive reviews about the results obtained under field conditions. Throughout this review, we examine the different methodologies that have been used in real scenarios and, based on representative case studies, we present the evolution and outcomes of the remediation strategies applied in real soil-contamination events where legacies of past metal mining activities or mine spills have posed a serious threat for soil conservation. So far, the best efficiencies at field-scale have been reported when using combined strategies such as physical containment and assisted-phytoremediation. We have also introduced the emerging problem of the heavy metal contamination of agricultural soils and the different strategies implemented to tackle this problem. Although remediation techniques used in real scenarios have not changed much in the last decades, there are also encouraging facts for the advances in this field. Thus, a growing number of mining companies publicise in their webpages their soil remediation strategies and efforts; moreover, the number of scientific publications about innovative highly-efficient and environmental-friendly methods is also increasing. In any case, better cooperation between scientists and other soil-related stakeholders is still required to improve remediation performance.

7.
Microb Biotechnol ; 16(5): 1069-1086, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36748404

RESUMO

Lignocellulosic residues are amongst the most abundant waste products on Earth. Therefore, there is an increasing interest in the utilization of these residues for bioethanol production and for biorefineries to produce compounds of industrial interest. Enzymes that breakdown cellulose and hemicellulose into oligomers and monosaccharides are required in these processes and cellulolytic enzymes with optimum activity at a low pH area are desirable for industrial processes. Here, we explore the fungal biodiversity of Rio Tinto, the largest acidic ecosystem on Earth, as far as the secretion of cellulolytic enzymes is concerned. Using colorimetric and industrial substrates, we show that a high proportion of the fungi present in this extremophilic environment secrete a wide range of enzymes that are able to hydrolyze cellulose and hemicellulose at acidic pH (4.5-5). Shotgun proteomic analysis of the secretomes of some of these fungi has identified different cellulases and hemicellulolytic enzymes as well as a number of auxiliary enzymes. Supplementation of pre-industrial cocktails from Myceliophtora with Rio Tinto secretomes increased the amount of monosaccharides released from corn stover or sugar cane straw. We conclude that the Rio Tinto fungi display a good variety of hydrolytic enzymes with high industrial potential.


Assuntos
Celulases , Ecossistema , Proteômica , Celulose/metabolismo , Celulases/metabolismo , Monossacarídeos
8.
Microb Biotechnol ; 16(2): 190-194, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36511364

RESUMO

Production of sustainable aviation fuels (SAFs) using microbes still requires huge research efforts to fulfill the needs of aviation, both in the biological utilization of raw materials as well as in the biological processes to convert these materials (oils, sugars, aromatic compounds and others) into SAFs. However, we should also be aware of the microbiology constraints that, in some cases, will not allow us to reach the commercial level and that, by creating false expectations we will harm the credibility of microbiologists. However, in our opinion microbiologists can and should continue to find new avenues for producing SAFs, and for evaluating the advantages and feasibility of their production. This last step will require a close collaboration between researchers and industry.


Assuntos
Aviação , Óleos
11.
Vet Med Sci ; 8(5): 1965-1968, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35920114

RESUMO

OBJECTIVE: Delayed cardiac tamponade, a life-threatening complication of pericardial effusion in humans, has rarely been described in large animal models. We report here a pig with cardiac tamponade that developed 29 days after cardiac surgery. STUDY DESIGN: Case report. ANIMALS: One 45-kg domestic pig. METHODS: Open-chest surgery was performed on a pig to induce chronic heart failure. At 15 days after surgery, the pig's breathing appeared laboured; induced heart failure was considered the cause. Routine heart failure medications were administered. RESULTS: On day 28, the pig's status deteriorated. On day 29, echocardiography performed just before the pig's death showed a large pericardial effusion, mainly in the lateral and anterior walls of the right heart, with several fibre exudation bands. The right heart was severely compressed with an extremely small right ventricle. An emergency sternotomy was unsuccessful. Pathologic examination showed a severely thickened, fibrous pericardium. The pericardial sac was distended (up to 4.5 cm) and was full of dark brown, soft, friable material. Epicardial haemorrhage with a fresh, organised thrombus was noted in the pericardium. CONCLUSION: Delayed tamponade occurring at least 15 days after open-chest surgery is easy to misdiagnose or overlook in large animal models where attention is often focused on primary pathological model changes. To decrease mortality in animal models, researchers should be aware of potential complications and use the same level of follow-up monitoring of large animals as in clinical care.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Tamponamento Cardíaco , Insuficiência Cardíaca , Derrame Pericárdico , Doenças dos Suínos , Animais , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Procedimentos Cirúrgicos Cardíacos/veterinária , Tamponamento Cardíaco/diagnóstico , Tamponamento Cardíaco/etiologia , Tamponamento Cardíaco/veterinária , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/patologia , Insuficiência Cardíaca/veterinária , Humanos , Derrame Pericárdico/diagnóstico , Derrame Pericárdico/etiologia , Derrame Pericárdico/cirurgia , Derrame Pericárdico/veterinária , Pericárdio/patologia , Suínos
12.
Front Immunol ; 13: 848586, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35865538

RESUMO

Cellular and humoral immune responses are essential for COVID-19 recovery and protection against SARS-CoV-2 reinfection. To date, the evaluation of SARS-CoV-2 immune protection has mainly focused on antibody detection, generally disregarding the cellular response, or placing it in a secondary position. This phenomenon may be explained by the complex nature of the assays needed to analyze cellular immunity compared with the technically simple and automated detection of antibodies. Nevertheless, a large body of evidence supports the relevance of the T cell's role in protection against SARS-CoV-2, especially in vulnerable individuals with a weakened immune system (such as the population over 65 and patients with immunodeficiencies). Here we propose to use CoVITEST (Covid19 anti-Viral Immunity based on T cells for Evaluation in a Simple Test), a fast, affordable and accessible in-house assay that, together with a diagnostic matrix, allows us to determine those patients who might be protected with SARS-CoV-2-reactive T cells. The method was established using healthy SARS-CoV-2-naïve donors pre- and post-vaccination (n=30), and further validated with convalescent COVID-19 donors (n=51) in a side-by-side comparison with the gold standard IFN-γ ELISpot. We demonstrated that our CoVITEST presented reliable and comparable results to those obtained with the ELISpot technique in a considerably shorter time (less than 8 hours). In conclusion, we present a simple but reliable assay to determine cellular immunity against SARS-CoV-2 that can be used routinely during this pandemic to monitor the immune status in vulnerable patients and thereby adjust their therapeutic approaches. This method might indeed help to optimize and improve decision-making protocols for re-vaccination against SARS-CoV-2, at least for some population subsets.


Assuntos
COVID-19 , SARS-CoV-2 , Anticorpos Antivirais , Humanos , Pandemias , Linfócitos T
14.
Cardiology ; 147(3): 364-366, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35045424
15.
Artigo em Inglês | MEDLINE | ID: mdl-34711531

RESUMO

OBJECTIVE: as scarce literature on the topic is available, we aimed to compare diagnostic utility of semi-quantitative versus visual analysis in labelled white blood cell scintigraphy (WBCS) for osteoarticular infection. One-day and two-day protocols were assessed, particularly in orthopaedic devices. MATERIAL AND METHODS: prospective study of 79 consecutive patients with suspected osteoarticular infection. In all patients, WBCS were performed at 30min, 4h, 8h and 24h. Images were analysed by grouping in two protocols: one-day-protocol (experts evaluated 30min, 4h and 8h planar images) and two-day-protocol (experts evaluated 30min, 4h and 24h planar images). Planar images were interpreted qualitative and semiquantitatively and also were compared grouping patients with and without orthopaedic devices. To find which cut-off value of the percentage variation could predict of osteoarticular infection, multiple cut-off values were calculated in both protocols from the Youden index. Three blinded readers analysed the images. RESULTS: Comparing final diagnosis visual analysis of the one-day-protocol provided better results with sensitivity of 95.5%, specificity of 93% and diagnostic accuracy of 93.7% (p<001) than the two-day-protocol with values of 86.4%, 94.7% and 92.4%, respectively (p<001). For semi-quantitative analysis, the one-day-protocol also obtained better results with sensitivity of 72.7%, specificity of 78.9% and accuracy of 77.2% (p<001) than two-day-protocol (no significant results; p=0.14), especially in the group of patients with orthopaedic devices (sensitivity of 100%, specificity of 79.5% and accuracy of 82.7%; p<001). CONCLUSIONS: most accurate approach in the diagnosis of osteoarticular infection corresponded to visual analysis in one-day-protocol that showed greater sensitivity and specificity than semi-quantitative analysis. Semi-quantitative analysis only could be useful when visual analysis is doubtful. In patients with joint prostheses, an increase in percentage variation above 9% obtained maximum sensitivity and negative predictive value.


Assuntos
Leucócitos , Humanos , Valor Preditivo dos Testes , Estudos Prospectivos , Sensibilidade e Especificidade
16.
Minim Invasive Ther Allied Technol ; 31(2): 168-178, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32543248

RESUMO

INTRODUCTION: Effectiveness of e-learning diminishes without the support of a pedagogical model to guide its use. In minimally invasive surgery (MIS), this has been reported as a limitation when technology is used to deliver contents without a sound pedagogical background. MATERIAL AND METHODS: We describe how a generic pedagogical model, the 3D pedagogy framework, can be used for setting learning outcomes and activities in e-learning platforms focused on MIS cognitive skills. A demonstrator course on Nissen fundoplication was developed following the model step-by-step in the MISTELA learning platform. Course design was informed by Kolb's Experiential learning model. Content validation was performed by 13 MIS experts. RESULTS: Ten experts agreed on the suitability of content structuring done according to the pedagogical model. All experts agreed that the course provides means to assess the intended learning outcomes. CONCLUSIONS: This work showcases how a general-purpose e-learning framework can be accommodated to the needs of MIS training without limiting the course designers' pedagogical approach. Key advances for its success include: (1) proving the validity of the model in the wider scope of MIS skills and (2) raising awareness amongst stakeholders on the need of developing training plans with explicit, rather than assumed, pedagogical foundations. Abbreviations: MIS: minimally invasive surgery; TEL: technology enhanced learning.


Assuntos
Instrução por Computador , Competência Clínica , Procedimentos Cirúrgicos Minimamente Invasivos
17.
Front Cardiovasc Med ; 8: 714774, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34733889

RESUMO

Introduction: Mitral regurgitation (MR) imposes volume overload on the left ventricle (LV) and elevates wall stress, triggering its adverse remodeling. Pronounced LV dilation, minimal wall thinning, and a gradual decline in cardiac ejection fraction (EF) are observed. The structural changes in the myocardium that define these gross, organ level remodeling are not known. Cardiomyocyte elongation and slippage have both been hypothesized, but neither are confirmed, nor are the changes to the cardiomyocyte structure known. Using a rodent model of MR, we used immunohistochemistry and transmission electron microscopy (TEM) to describe the ultrastructural remodeling of the cardiomyocyte. Methods: Twenty-four male Sprague-Dawley rats (350-400 g) were assigned to two groups: group (1) rats induced with severe MR (n = 18) and group (2) control rats that were healthy and age and weight matched (n = 6). MR was induced in the beating heart using a 23-G ultrasound-guided, transapical needle to perforate the anterior mitral leaflet, and the rats were followed to 2, 10, and 20 weeks (n = 6/time-point). Echocardiography was performed to quantify MR severity and to measure LV volume and function at each time-point. Explanted myocardial tissue were examined with TEM and immunohistochemistry to investigate the ultrastructural changes. Results: MR induced rapid and significant increase in end-diastolic volume (EDV), with a 50% increase by 2 weeks, compared with control. Rise in end-systolic volume (ESV) was more gradual; however, by 20 weeks, both EDV and ESV in MR rats were increased by 126% compared with control. A significant decline in EF was measured at 10 weeks of MR. At the ultrastructural level, as early as 2 weeks after MR, cardiomyocyte elongation and increase in cross-sectional area were observed. TEM depicted sarcomere shortening, with loss of Z-line and I-band. Desmin, a cytoskeletal protein that is uniformly distributed along the length of the cardiomyocyte, was disorganized and localized to the intercalated disc, in the rats induced with MR and not in the controls. In the rats with MR, the linear registry of the mitochondrial arrangement along the sarcomeres was lost, with mitochondrial fragmentation, aggregation around the nucleus, and irregularities in the cristae. Discussion: In the setting of chronic mitral regurgitation, LV dilatation occured by cardiomyocyte elongation, which manifests at the subcellular level as distinct ultrastructural alterations of the sarcomere, cytoskeleton, and mitochondria. Since the cytoskeleton not only provides tensegrity but has functional consequences on myocyte function, further investigation into the impact of cytoskeletal remodeling on progressive heart failure or recovery of function upon correcting the valve lesion are needed.

18.
Plants (Basel) ; 10(11)2021 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-34834668

RESUMO

Heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) are toxic components of atmospheric particles. These pollutants induce a wide variety of responses in plants, leading to tolerance or toxicity. Their effects on plants depend on many different environmental conditions, not only the type and concentration of contaminant, temperature or soil pH, but also on the physiological or genetic status of the plant. The main detoxification process in plants is the accumulation of the contaminant in vacuoles or cell walls. PAHs are normally transformed by enzymatic plant machinery prior to conjugation and immobilization; heavy metals are frequently chelated by some molecules, with glutathione, phytochelatins and metallothioneins being the main players in heavy metal detoxification. Besides these detoxification mechanisms, the presence of contaminants leads to the production of the reactive oxygen species (ROS) and the dynamic of ROS production and detoxification renders different outcomes in different scenarios, from cellular death to the induction of stress resistances. ROS responses have been extensively studied; the complexity of the ROS response and the subsequent cascade of effects on phytohormones and metabolic changes, which depend on local concentrations in different organelles and on the lifetime of each ROS species, allow the plant to modulate its responses to different environmental clues. Basic knowledge of plant responses toward pollutants is key to improving phytoremediation technologies.

19.
mSphere ; 6(4): e0041221, 2021 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-34378981

RESUMO

Rhizoremediation is based on the ability of microorganisms to metabolize nutrients from plant root exudates and, thereby, to cometabolize or even mineralize toxic environmental contaminants. Novosphingobium sp. HR1a is a bacterial strain able to degrade a wide variety of polycyclic aromatic hydrocarbons (PAHs). Here, we have demonstrated that the number of CFU in microcosms vegetated with clover was almost 2 orders of magnitude higher than that in nonvegetated microcosms or microcosms vegetated with rye-grass or grass. Strain HR1a was able to eliminate 92% of the phenanthrene in the microcosms with clover after 9 days. We have studied the molecular basis of the interaction between strain HR1a and clover by phenomic, metabolomic, and transcriptomic analyses. By measuring the relative concentrations of several metabolites exudated by clover both in the presence and in the absence of the bacteria, we identified some compounds that were probably consumed in the rhizosphere; the transcriptomic analyses confirmed the expression of genes involved in the catabolism of these compounds. By using a transcriptional fusion of the green fluorescent protein (GFP) to the promoter of the gene encoding the dioxygenase involved in the degradation of PAHs, we have demonstrated that this gene is induced at higher levels in clover microcosms than in nonvegetated microcosms. Therefore, the positive interaction between clover and Novosphingobium sp. HR1a during rhizoremediation is a result of the bacterial utilization of different carbon and nitrogen sources released during seedling development and the capacity of clover exudates to induce the PAH degradation pathway. IMPORTANCE The success of an eco-friendly and cost-effective strategy for soil decontamination is conditioned by the understanding of the ecology of plant-microorganism interactions. Although many studies have been published about the bacterial metabolic capacities in the rhizosphere and about rhizoremediation of contaminants, there are fewer studies dealing with the integration of bacterial metabolic capacities in the rhizosphere during PAH bioremediation, and some aspects still remain controversial. Some authors have postulated that the presence of easily metabolizable carbon sources in root exudates might repress the expression of genes required for contaminant degradation, while others found that specific rhizosphere compounds can induce such genes. Novosphingobium sp. HR1a, which is our model organism, has two characteristics desirable in bacteria for use in remediation: its ubiquity and the capacity to degrade a wide variety of contaminants. We have demonstrated that this bacterium consumes several rhizospheric compounds without repression of the genes required for the mineralization of PAHs. In fact, some compounds even induced their expression.


Assuntos
Medicago/química , Fenantrenos/metabolismo , Raízes de Plantas/química , Sphingomonadaceae/fisiologia , Biodegradação Ambiental , Medicago/efeitos dos fármacos , Fenantrenos/análise , Fenantrenos/farmacologia , Extratos Vegetais/farmacologia , Microbiologia do Solo , Sphingomonadaceae/efeitos dos fármacos
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