98 research outputs found
Programação de um sistema de inspecção artificial dinâmica
Mestrado em Engenharia Electrónica e Telecomunicaçõe
Investigação da produção do ácido itacónico pela bactéria Escherichia coli
Dissertação de mestrado em BioengenhariaO ácido itacónico (AI) é um ácido carboxílico que apresenta elevado potencial para ser usado
como monómero na síntese de diversos materiais sintéticos. Actualmente, é produzido por
fermentação com fungos filamentosos, obtendo-se rendimentos mais elevados em comparação
com outras espécies, nomeadamente bacterianas. Entre as diversas espécies de fungos, o
Aspergillus terreus e o Aspergillus niger são as que apresentam melhores níveis de produção deste
ácido (> 80g.L-1). No entanto, em comparação com o processo de produção de ácido cítrico (> 200
g.L-1) utilizando estes mesmos fungos, a produtividade é consideravelmente mais baixa. Existe por
isso a necessidade de um desenvolvimento contínuo de novas tecnologias de fermentação e a
procura de novas estirpes produtoras, incluindo organismos geneticamente modificados, de modo
a melhorar o processo biológico.
O AI é sintetizado através da atividade catalítica da cis-aconitato descarboxilase (CAD), cujo
gene pode ser isolado de uma vasta gama de fungos filamentosos. A sua clonagem em organismos
hospedeiros, como as bactérias, possibilita a produção de AI usando plataformas microbianas com
melhores características para a implementação industrial, essencialmente no que respeita às
condições operacionais. A abordagem deste trabalho parte do facto da Escherichia coli ser
actualmente reconhecida como uma das plataformas microbianas adequadas à produção
recombinante de diversos produtos, incluindo ácidos orgânicos tais como o AI.
O efeito do AI na fisiologia e no metabolismo da E. coli em cultura com diferentes substratos
foi inicialmente testado. Os resultados apontam que o AI não deverá ser usado como fonte de
carbono pela E. coli, facto que poderia afectar a produtividade final do processo, mas afecta o
crescimento celular da E. coli quando se usam fontes de carbono gluconeogénicas, nomeadamente
acetato. Posteriormente, foi avaliada a capacidade de produção de uma estirpe de E. coli
recombinante BL21(DE3) pET52-CAD com o gene CAD de A. terreus. Nestes ensaios foram
testadas apenas as condições de pH do meio fermentativo, dado ser um dos factores mais
relevantes na produção de AI. Os resultados mostram que a gama de pH testada não terá efeito na
produção de AI, mas afecta a formação de biomassa. Os níveis de produção obtidos (0,034 g.L-1)
estão ainda muito abaixo de outros processos de produção (80 g.L-1 em A. terreus). Embora os
resultados de produção sejam pouco promissores, deve ter-se em conta a necessidade de testar
outras condições fermentativas para avaliar a produção óptima de AI em E. coli. Para além disso,
existe a possibilidade de manipulação da E. coli por meio de estratégias de engenharia metabólica,
que abre novas expectativas relativamente à optimização deste processo.Itaconic acid (IA) is a carboxylic acid with a high potential to be used as a monomer in the
synthesis of various materials. Currently, IA is produced by fermentation using filamentous fungi,
providing high product yields compared to other microorganisms, particularly bacteria. Among the
fungal species, Aspergillus terreus and Aspergillus niger present the best production levels (> 80g.L-
1), but titers are still lower compared to the production of citric acid with fungi (>200 g.L-1).
Therefore, there is a need for a continuous development of new fermentation technologies and the
search for new strains, including genetically modified strains to enhance the production of IA.
The IA is synthesized through the enzymatic activity of cis-aconitate decarboxylase (CAD),
whose gene can be isolated from a wide range of filamentous fungi, but preferentially from A.
terreus. Cloning the CAD gene in host organisms, like E. coli, allows the production of IA by
organisms that present more favorable properties for the industrial production, mainly with regards
to operating conditions and costs associated with the industrial process.
The purpose of this work relies on the fact that E. coli has been recognized as a wellestablished
platform for the microbial production of various recombinant products, including
organic acids and, as such, may also be interesting for the production of IA at the industrial-scale.
Thus, the investigation of the IA effects on the physiology of E. coli cells grown at different
conditions (i.e., carbon sources) was prioritized, so that we could understand the most favorable
conditions for the production of IA in E. coli. The results pointed out that IA may not be used as a
carbon source, a fact that would affect the final yield of the process, but limits cell growth when
using gluconeogenic carbon sources. Then, a recombinant E. coli BL21 (DE3) pET52-CAD strain
with the CAD gene from A. terreus was used to evaluate the production of IA. In these assays,
different pH conditions were tested, which revealed no effects on the production of IA at the range
of pH values tested. Although the recombinant activity of CAD was not affected, the cell growth was;
which indicates the potential activation of cellular mechanisms, perhaps to maintain the
intracellular pH that affect cellular growth. The production levels obtained (0.034 g.L1) were still
much lower compared with other production process (for example 80g.L-1 in A. terreus), but
metabolic engineering strategies opens new promising perspectives for the optimization of this
process
Clostridium perfringens associated with dairy farm systems show diverse genotypes
Clostridium perfringens is a bacterial species of importance to both public and animal health. Frequently found in food system environments, it presents a risk to food animal health such as dairy herds, and may cross contaminate associated ingredients or food products, with potential to cause sporadic and outbreaks of disease in human populations, including gastroenteric illness. In this study, we characterized C. perfringens isolated from bovine, caprine, and ovine dairy farm systems (n = 8, 11 and 4, respectively). Isolates were phenotypically screened for antimicrobial sensitivity profiling, and subjected to whole genome sequencing to elucidate related genetic markers, as well as examine virulence gene markers, mobile genetic elements, and other features. Both toxin type A and type D isolates were identified (78 % and 22 % of isolates, respectively), including 20 novel sequence types. Resistance to clindamycin was most prevalent among antibiotics screened (30 %), followed by erythromycin (13 %), then penicillin and tetracycline (4 %), although an additional 3 isolates were non-susceptible to tetracycline. Most isolates harboured plasmids, which mobilised virulence markers such as etx, cpb2, and resistance markers tetA(P), tetB(P), and erm(Q), on conjugative plasmids. The presence of type D isolates on caprine farms emphasizes the need for control efforts to prevent infection and potential enterotoxemia. Clostridium perfringens enterotoxin (cpe) was not identified, suggesting lower risk of gastrointestinal illness from contaminated foods, the presence of other virulence and antimicrobial resistance markers suggests farm hygiene remains an important consideration to help ensure food safety of associated dairy foods produced
Research report of the LookCrim Project, from conceptualization to practice
info:eu-repo/semantics/publishedVersio
Pharmacokinetic interactions between clopidogrel and rosuvastatin: Effects on vascular protection in subjects with coronary heart disease
Universidade Federal de São Paulo, Dept Med, Div Cardiol, São Paulo, BrazilUniv São Paulo, Inst Phys, Natl Inst Complex Fluids, São Paulo, BrazilGaleno Lab, Campinas, SP, BrazilUniversidade Federal de São Paulo, Dept Med, Div Cardiol, São Paulo, BrazilWeb of Scienc
Antioxidant capacity of Macaronesian traditional medicinal plants
The use of many traditional medicinal plants is often hampered by the absence
of a proper biochemical characterization, essential to identify the bioactive compounds present. The leaves from five species endemic to the Macaronesian islands with recognized
ethnobotanical applications were analysed: Apollonias barbujana (Cav.) Bornm., Ocotea
foetens (Ainton) Baill, Prunus azorica (Mouill.) Rivas-Mart., Lousã, Fern. Prieto, E. Días,
J.C. Costa & C. Aguiar, Rumex maderensis Lowe and Plantago arborescens Poir. subsp.
maderensis (Dcne.) A. Hans. et Kunk.. Since oxidative stress is a common feature of most
diseases traditionally treated by these plants, it is important to assess their antioxidant
capacity and determine the molecules responsible for this capacity. In this study, the
antioxidant capacity of these plants against two of the most important reactive species in
human body (hydroxyl and peroxyl radicals) was determined. To trace the antioxidant
origin total phenol and flavonoid contents as well as the polyphenolic profile and the
amount of trace elements were determined. There was a wide variation among the species
analysed in what concerns their total leaf phenol and flavonoid contents. From the High
Performance Liquid Chromatography (HPLC) electrochemically detected peaks it was
possible to attribute to flavonoids the antioxidant capacity detected in A. barbujana, O.
foetens, R. maderensis and P. azorica extracts. These potential reactive flavonoids were
identified for A. barbujana, R. maderensis and P. azorica. For R. maderensis a high
content (7 mg g-1 dry weight) of L-ascorbic acid, an already described antioxidant
phytomolecule, was found. A high content in selenomethionine (414.35 μg g-1 dry weight)
was obtained for P. arborescens subsp. maderensis extract. This selenocompound is
already described as a hydroxyl radical scavenger is reported in this work as also
possessing peroxyl radical scavenging capacity. This work is a good illustration of
different phytomolecules (flavonoids, organic acids and selenocompounds), presents in
leaves of the five traditional medicinal plants endemic to Macaronesia, all exhibiting
antioxidant propertiesinfo:eu-repo/semantics/publishedVersio
Equoterapia: do âmbito escolar ao tratamento da depressão e esquizofrenia, um relato de experiência / Equine-Assisted Therapy: from the school context to the treatment of depression and schizophrenia, an experience report
A significativa expansa?o da Rede Federal de Educac?a?o Profissional, Cienti?fica e Tecnolo?gica trouxe mais que a criação e multiplicac?a?o de Institutos Federais por todo o Brasil com isso, perceberam-se reais possibilidades de quebra de paradigmas no referido âmbito educacional. Nesse contexto, foi implantado o primeiro centro de equoterapia da Rede Federal no Instituto Federal de Educac?a?o, Ciência e Tecnologia Goiano-Campus Ceres, onde este estudo foi desenvolvido com o objetivo de analisar possíveis contribuições do método equoterápico para pessoas diagnosticadas com esquizofrenia e/ou com histórico de depressão. Em parceria com a Prefeitura Municipal de Ceres-Goia?s, a equipe de atendimento foi composta por psicólogo, pedagogo, fisioterapeuta, fonoaudio?logo, terapeuta ocupacional, veterinário e educador físico a se revezarem nos atendimentos com duração média de 30 minutos. No início e ao final de quatro sessões foi aplicado um questionário embasado na escala Likert com os resultados discutidos junto à análise observacional dos terapeutas e o feedback dos participantes. A composição da amostra envolveu 11 participantes de ambos os sexos com idade média de 44,81 anos (±11,49). Verificou-se sintonia entre as respostas dos questionários e a análise observacional dos terapeutas, ficando evidenciados ganhos relativos à socialização, autoestima e principalmente afetos positivos, ao que se conclui que a equoterapia pode contribuir a nível do bem-estar e influenciar positivamente no tratamento de pessoas com esquizofrenia e depressão
Extracellular vesicles in infectious diseases caused by protozoan parasites in buffaloes
Background:
Extracellular vesicles (EVs) are small membrane-bound vesicles of growing interest in vetetinary parasitology. The aim of the present report was to provide the first isolation, quantification and protein characterization of EVs from buffalo (Bubalus bubalis) sera infected with Theileria spp.
Methods:
Infected animals were identified through optical microscopy and PCR. EVs were isolated from buffalo sera by size-exclusion chromatography and characterized using western blotting analysis, nanoparticle tracking analysis and transmission electron microscopy. Subsequently, the proteins from isolated vesicles were characterized by mass spectrometry.
Results:
EVs from buffalo sera have shown sizes in the 124-140 nm range and 306 proteins were characterized. The protein-protein interaction analysis has evidenced biological processes and molecular function associated with signal transduction, binding, regulation of metabolic processes, transport, catalytic activity and response to acute stress. Five proteins have been shown to be differentially expressed between the control group and that infected with Theileria spp., all acting in the oxidative stress pathway.
Conclusions:
EVs from buffaloes infected with Theileria spp. were successfully isolated and characterized. This is an advance in the knowledge of host-parasite relationship that contributes to the understanding of host immune response and theileriosis evasion mechanisms. These findings may pave the way for searching new EVs candidate-markers for a better production of safe biological products derived from buffaloes
Relatório de execução do Projeto LookCrim, da conceptualização à prática
info:eu-repo/semantics/publishedVersio
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