Dissertações em Biotecnologia (Mestrado) - PPGBIOTEC/ICB

URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/6090

O Mestrado em Biotecnologia teve início em 2011 e funciona no Programa de Pós-Graduação em Biotecnologia (PPGBIOTEC) do Instituto de Ciências Biológicas (ICB) da Universidade Federal do Pará (UFPA).

Navegar

Agora exibindo 1 - 20 de 30

Acesso aberto (Open Access)
Análise e caracterização do genoma mitocondrial: um estudo de caso de Cyprinodon sp. e Arapaima gigas
(Universidade Federal do Pará, 2025-05) MACEDO, Daralyns Borges; RAMOS, Rommel Thiago Juca; http://lattes.cnpq.br/1274395392752454; https://orcid.org/0000-0002-8032-1474
The advancement of next-generation sequencing technologies has enabled large-scale characterization of mitochondrial genomes across various species. However, even among fish — the group with the highest number of sequenced mitochondrial genomes — only 9.7% of valid species are represented in genetic databases. This gap limits conservation programs, which rely on genetic data to guide management strategies. The genus Cyprinodon, composed of several threatened species restricted to isolated habitats, is particularly vulnerable to habitat loss and interspecific hybridization. In this context, the present study aimed to sequence and characterize the mitochondrial genome of Cyprinodon sp., in order to clarify phylogenetic relationships and evolutionary aspects of the Cyprinodontidae family. The sample was sequenced using the Illumina HiSeq platform, assembled with Megahit software, and analyzed using tools such as MitoZ, Circos, ClustalW, MrBayes, and Figtree. The complete mitogenome comprises 16,500 bp and contains 37 genes. Concurrently, Arapaima gigas, an iconic Amazonian species historically important to fisheries, is currently threatened with extinction and classified as “Data Deficient” by the IUCN. In the Tocantins River, heavily impacted by human activities, fishers from 25 communities reported the near disappearance of the species, with only one recent sighting on Jaracuera Island. The disappearance of A. gigas has severe economic consequences for local communities. Without collaboration between fishery managers and local populations, the species faces an imminent risk of regional extinction, further exacerbated by the lack of data on its fishing dynamics in northern Brazil.
Acesso aberto (Open Access)
Purificação, caracterização e avaliação de peptídeo antimicrobiano produzido pela cianobactéria amazônica Lyngbya sp. CACIAM 07
(Universidade Federal do Pará, 2024-06) PINTO NETO, Joaquim da Silva; SANTOS, Agenor Valadares; http://lattes.cnpq.br/9530734927662735; https://orcid.org/0000-0002-2690-2841
Cyanobacteria are photosynthesizing microorganisms that, together with micro and macroalgae, are responsible for most of the oxygen released into the atmosphere. One defense mechanism of cyanobacteria is the production of compounds that exhibit antimicrobial, allelopathic, and antiparasitic activities, protecting the organism against attacks from other species of cyanobacteria, predators, and microorganisms in general. The genus Lyngbya is one of the most studied due to its promising production of molecules of biotechnological interest, such as peptides, proteins, and secondary metabolites, which can be used in various areas to address problems that afflict society and the environment, such as crop pests, food contamination, and the lack of new commercial antimicrobials. The aim of this study was to obtain, evaluate, and characterize the peptide with antimicrobial activity produced by the Amazonian cyanobacterium Lyngbya sp. CACIAM 07. The extract was obtained from the dried biomass of the cyanobacterium, and its antimicrobial activity was evaluated by well diffusion against gram-positive (Bacillus subtilis ATCC 6633, Listeria monocytogenes ATCC 6477, and Corynebacterium fimi NCTC 5) and gram-negative (Salmonella typhimurium ATCC 14021) bacteria. The aqueous extract showed the greatest activity against the target bacteria, inhibiting the growth of three of the four bacteria used in this study: Bacillus subtilis ATCC 6633, Salmonella typhimurium ATCC 14021, and Listeria monocytogenes ATCC 6477. It also inhibited the growth of the cyanobacterium Cyanobium sp. CACIAM 14. The crude aqueous extract was purified using molecular exclusion chromatography and then reversed-phase liquid chromatography. The collected fractions were tested for their antimicrobial and allelopathic activity, with fraction C7B1 showing the best activity against Bacillus subtilis ATCC 6633, Salmonella typhimurium ATCC 14021 and demonstrating allelopathic activity against Synechococcus sp. CACIAM 66. According to the chromatograms, it was possible to determine the size of the molecule, which was 12 kDa, consistent with an antimicrobial peptide. Thus, in this work, it was possible to isolate, analyze, and partially characterize the activity of the possible AMP obtained from Lyngbya sp. CACIAM 07, a cyanobacterium isolated from the Amazon region. We would point out that no molecule with antimicrobial or allelopathic activity from this strain has been described in the literature to date.
Acesso aberto (Open Access)
Análise da expressão gênica de pacientes com adenocarcinoma gástrico associado ao vírus Epstein-Barr
(Universidade Federal do Pará, 2024-08) SILVA, Valéria Cristiane Santos da; MOREIRA, Fabiano Cordeiro; http://lattes.cnpq.br/5745396559731337
Infection with the Epstein-Barr virus (EBV) is one of the risk factors for gastric cancer (GC). Epstein-Barr is a virus with oncogenic activity and was the first to be associated with malignant diseases such as lymphomas and carcinomas. Thus, EBV detection can be performed both by in situ hybridization and, currently, by using RNA sequencing techniques to identify the presence of viral genes in samples. In this context, aiming to better understand the EBV-positive subtype, this study proposed a molecular classification based on RNA sequencing of 76 tumor samples from patients diagnosed with GC. RNA sequencing of the samples was performed, and molecular classification was done using the Kraken2 software. Of the 76 samples, 8 were considered positive according to the adopted method. Subsequently, to understand the different mechanisms by which EBV might be acting in gastric cancer, we analyzed the patterns of human gene expression in samples classified as positive and negative. In our study, there are approximately 834 differentially expressed genes, of which 92 have an AUC greater than 0.85. These genes are associated with tumor progression, cellular metabolism, and innate and adaptive immunity. Additionally, viral genes expressed in the positive samples were evaluated, and we found manifestations of both lytic phase and latent phase genes. Finally, our study presents an efficient strategy for the molecular classification of EBV-positive
Acesso aberto (Open Access)
Análise proteômica de cultura macrófagica tratada com ácido kójico
(Universidade Federal do Pará, 2023-07) ALMEIDA, Heyder Coutinho; SANTOS, Agenor Valadares; http://lattes.cnpq.br/9530734927662735; https://orcid.org/0000-0002-2690-2841
Kojic acid (AK) is a natural fungal secondary metabolite, produced by some species of Aspergillus, Penicillium and Acetobacter, through the direct biotransformation of carbon substrates such as glucose, sucralose, ethanol, among others. AK was originally isolated in Japan, in 1907, from Aspergillus oryzae mycelia, it is used in the cosmetic industry in the form of gels and soap and is used to obtain the effect of whitening the skin by inhibiting the enzyme tyrosinase, reducing the production of formation of melanin, it also blocks the formation of pigmentation and evens out the skin tone. It is also applied as a food additive for the prevention of enzymatic browning, as it is a metal chelator and a potent antioxidant. Although AK has numerous biological functions, only recently studies on in vitro proliferation and cytotoxicity have been reported, but still limitedly regarding its effect on immune cells. Macrophages are among the most important defense cells that specifically recognize and respond to foreign bodies, apoptosis cells and pathogens. Through the activation process, there is an increased proliferation of macrophages, which undergo various morphological changes, such as an increase in dissemination and adhesion abilities, phagocytosis activity, ROS generation, antigen presentation and cytokine production. According to the classification of biological functions, our results revealed that in both Kojic acid concentrations, the 14 expressed proteins have a predicted function related to cell cycle and redox processes.
Acesso aberto (Open Access)
Bioprospecção de leveduras com potencial para a produção de carotenoides presentes em uma microrregião do bioma Amazônia
(Universidade Federal do Pará, 2024-11) LUCAS, David Cristian Rodrigues; CHISTÉ, Renan Campos; http://lattes.cnpq.br/0583058299891937; https://orcid.org/0000-0002-4549-3297
Carotenoids are bioactive compounds used as natural pigments and are found in plants, animals, algae and microorganisms. Some of these compounds are precursors of vitamin A and have benefits to human health such as strengthening the immune system and reducing the risk of chronic degenerative diseases. In industry, the production of carotenoids is obtained mainly by chemical synthesis or through algae and plant extracts. However, with the growing concern about utilization of chemical additives in food by many consumers, the interest in obtaining them through biotechnological processes and diverse microorganisms may synthesize them, such as yeasts. In this work, an exploration study was carried out focused on molecular identification of carotenoid-producing yeasts available in a microregion of Amazonia biome, with the aim of highlighting promising microorganisms for future industrial applications. Samples were collected from leaves, flowers, soil, and bark trees, among them, 4 promising strains were isolated and identified from phyllosphere of philodendron (Philodendron hederaceum): Rhodosporidiobolus ruineniae (PH-18(I)), Rhynchogastrema noutii or Hannaella pagnoccae (dPH-8(I)), Leucosporidium egoroviorum or Lyomyces sp. (dPH-8(II)), and Rhodotorula diobovata or Rhodotorula glutinis (PH-22(II)). The strain PH-18(I) showed a biomass yield of 0.26% to 0.76% and total carotenoid content of 139.70 μg/g of dry biomass. The strain dPH-8(I) showed a biomass yield of 0.43% to 0.96 % and total carotenoid content of 54.26 μg/g. The strain dPH-8(II) demonstrated a biomass yield of 0.35% to 1.12% and total carotenoid content of 52.71 μg/g, while the strain PH-20(II) demonstrated a biomass yield of 11.63 % to 23.67 % and total carotenoid content of 44.98 μg/g. The carotenoids identified in this study were 13Z-β-carotene, (all-E)-β-carotene and 9Z-β-carotene, being (all-E)-β-carotene the majority. Results found in this study highlight a promising perspective for future applications of carotenoid-producing yeasts in the Amazonia biome, being an excellent alternative to replace the process of obtaining carotenoids by synthetic means or by exploitation of vegetal sources.
Acesso aberto (Open Access)
Prospeção de aminoácidos tipo micosporinas (MAAs) em cianobactérias da Amazônia oriental
(Universidade Federal do Pará, 2014-06-30) ARAÚJO, Sanclayver Corrêa; GONÇALVES, Evonnildo Costa; http://lattes.cnpq.br/8652560763793265
Mycosporine-like amino acids (MAAs) are low molecular weight water soluble compounds wuich biosynthesis was thought to occur via shikimate pathway in bacteria, phytoplankton and macroalgae. Recently evidences show its biosynthesis via the pentose pathway in a cyanobacterium. Due to its high extinction molar coefficient in UV region, they provide protection against the damaging effects of UV radiation and have potential for use in sunscreens. In previous works it was described a biosynthetic cluster for shinorine with the enzymes dehydroquinate synthase, present in the shikimate pathway, O-methyltransferase, and ATP-grasp and NRPS-like enzymes. It was observed that the enzyme 2-epi-5-epi-valiolone synthase, which link the pentose pathway with MAAs production would lead to formation of 4-deoxygadusol, precursor of MAAs. In this work a genomics approach was carried out so find these genes so that MAAs production potential in Amazonian cyanobacteria of the Coleção Amazônica de Cianobactérias e Microalgas, CACIAM 14, CACIAM 53, CACIAM 54 and CACIAM 57 strains was assessed, as well as an analysis through capillary chromatography coupled to electrospray mass spectrometryof the metabolites in CACIAM 14. The genes Dehydroquinate synthase and o-methyltransferase were found in all the strains studied. The genes of pentose pathway Ribulose-phosphate-3-epimerase and transketolase were detected in the strains CACIAM 14, CACIAM 53 and CACIAM 57, what may suggest that in these strains MAAs could be produced by both pathways while in CACIAM 57 MAAs could be produced by shikimate pathway only. In CACIAM 14 strain, fragments of mass to charge relationship 186 and 197 were found in the same retention time of a precursor ion of m/z 333, what could be related to shinorine. Therefore, the strains CACIAM 53, 54 and 57 are potentially producers of MAAs due to possessing biosynthetic genes and CACIAM 14 is shinorine producer.
Acesso aberto (Open Access)
Caracterização antigênica, físico-química e biológica do vírus BE AR 701405, obtido a partir de mosquitos da espécie Psorophora (Jan) ferox, capturados em Altamira – Pará
(Universidade Federal do Pará, 2014-03-26) ARAÚJO, João Batista dos Santos; LEAL, Élcio de Souza; http://lattes.cnpq.br/1158983666415285
The BE AR 701405 virus was isolated from a pool of Psorophora (Jan.) ferox mosquitoes captured in the municipality of Altamira, Para state, Northern Brazil, in 2006. The objective of this study was the physicochemical, biological and antigenic characterization of the BE AR 701405 virus in order to provide data for it taxonomic classification. Newborn mice inoculated by intracerebral route showed evidences of neurological manifestations, such as chill and motor disorders after the infection with the virus BE AR 701405. Cytophatic effect (CPE) was in infected Aedes albopictus C6/36 cells was not clearly observed, however in VERO cells CPE was observed after 48 hors post infection. The virus load was determined in 10-4,1 LD50/ 0.02 mL and the titer after DCE analysis was calculated in 10−2,6 LD50/0,02 mL. The BE AR 701405 virus reacted antigenically with Pixuna virus hiperimmune serum. In conclusion, the studied vírus was sensible to the DCA solvent suggesting that it is an enveloped virus. Furthermore, by serology this virus was identified as a member of the group A, genus Alphavirus, family Togaviridae, more closely related to Pixuna virus. In addition, newborn mice, as well as C6/36 and VERO cells demonstrated to be sensible to the infection by the BE AR 701405 vírus. Further studies are needed to better understand the antigenic relationship between the BE AR 701405 virus and Pixuna virus.
Acesso aberto (Open Access)
AutoAssemblyD software para submissão e gerenciamento de montagem de genomas a partir de modelos XML
(Universidade Federal do Pará, 2014-01-24) VERAS, Adonney Allan de Oliveira; SILVA, Artur Luiz da Costa da; http://lattes.cnpq.br/7642043789034070
Technologies for second-generation sequencing provided a major breakthrough of the genome, making its use a landmark that has revolutionized biology. These platforms are characterized by a reduction in sequencing time, high data production and low cost per base sequenced, however, these devices produce data mostly consist of short readings which represents a major challenge for reconstruction of the genome due to this new feature readings of computational tools had to be developed to accomplish the task of assembling their example we Velvet, AllPaths, Abyss, SOAPdenovo2, Edena. However, most of these applications are executed through command lines extended and composed of several parameters must follow the standard syntax to use, because in case of errors in the syntax is the possibility of not obtaining the best result, with the aim of solve this problem we present the AutoAssemblyD that besides providing the use of these assemblers through a graphical interface also enables the management of these executions remotely.
Acesso aberto (Open Access)
Cianotoxinas em ostras e em águas de cultivo da costa norte do Brasil
(Universidade Federal do Pará, 2016-08-31) CABRAL, Jardecicléia Patrícia da Silva; SCHNEIDER, Maria Paula Cruz; http://lattes.cnpq.br/3901112943859155
Cyanobacteria are photosynthetic prokaryotic organisms and under conditions favorable to their growth can form blooms. They are also capable of producing cyanotoxins, secondary metabolites that have a toxic effect on eukaryotic organisms including man. As part of phytoplankton the cyanobacteria participate in the food chains, thus the ingestion of shellfish, that have been continuously fed toxic cyanobacteria and accumulated the toxins in their tissues generates the possibility of transfer to the man through their consumption bringing serious risks to their health. There is still very little research on the contamination (by cyanotoxins) of shellfish intended for human consumption. Therefore, this study was to verify the occurrence of cyanotoxins in culture waters and in the tissue of oysters destined for human consumption. The water and oyster samples were collected from two municipalities located in the northeast of Pará. The cyanotoxins research was performed using High Performance Liquid Chromatography (HPLC). The cyanobacteria present in the water, isolated and cultured from oyster shells were identified. No microcystins and saxitoxins were detected in water samples and oyster extracts from both growing sites. However, three genera of cyanobacteria - Aphanizomenon, Oscillatoria and Phormidium were identified in Curuçá and three genera of cyanobacteria in São Caetano de Odivelas - Aphanothece, Oscillatoria and Phormidium, all known to contain toxic species. The presence of saxitoxins in extracts from cyanobacterial cultures was detected from the oyster shells of both growing sites, indicating the presence of toxic species despite the absence of bloom. In this study, it was verified that the cultivation of oyster sites are suitable for consumption, free of contamination by microcystins and saxitoxins, however, it is necessary to implement specific legislation and the monitoring of these crops in order to ensure consumer health.
Acesso aberto (Open Access)
Produção e avaliação da atividade antioxidante de metabólitos secundários de Piper divaricatum G. Meyer sob diferentes condições de cultivo
(Universidade Federal do Pará, 2015-08-06) CORPES, Rosana Silva; SILVA, Joyce Kelly do Rosário da; http://lattes.cnpq.br/2278686174214080
Many species of the genus Piper are widely distributed in the Amazon and various biological applications because of large structural diversity of its secondary metabolites. The species Piper divaricatum, is endemic in the Amazon and produces in its essential oil high concentrations of methyleugenol (50-90%), an phenylpropanoid with antioxidant and fungicidal properties. Because of its potential applications, the objective of this study was to establish the in vitro cultivation and comparing the biosynthesis of secondary metabolites and antioxidant properties with the in vivo cultivation. For establish the in vitro culture were used shoot apexes on Murashige e Skoog medium with addition of regulator BAP 0.5 mg.mL-1. For in vivo cultivation, micropiles were propagated in the greenhouse in vermiculite and adding nutritious Murashige e Skoog solution. The volatile compounds identified in the leaves of seedlings grown in vivo were methyleugenol, β-elemene and E-β-ocimene, which did not differ from in vivo cultivation, with the exception of 90 days. The in vitro culture of roots was not efficient to produce phenylpropanoids and presented a very different profile compared to the in vivo cultivation of terpenes. In general, for plants in vitro cultivated there was no statistically significant difference in the phenolics compounds content and antioxidant activity in the leaves. However, the antioxidant activity of roots was significant. The results support the hypothesis that in vitro regenerated plants can synthesize metabolites similar the matrix plant and maintain their biological properties.
Acesso aberto (Open Access)
Efeito do meio condicionado por células tronco mesenquimais derivadas de tecido adiposo na maturação de oócitos bovinos e posterior desenvolvimento embrionário in vitro
(Universidade Federal do Pará, 2016-07-29) VALENTE, Juliana Vieitas; MIRANDA, Moysés dos Santos; http://lattes.cnpq.br/3354029928888919
Stem cells are known for their property of self-renewal, differentiation into various cell lineages and immunomodulatory capabilities, in addition to express a large number of adhesion molecules, extracellular matrix proteins, cytokines and growth factor recptors, allowing interactions with other cells. They can be isolated from various tissues, but adult stem cells derived from adipose tissue stroma (MSC-d) have the advantage of being easely isolated, high yield and low morbidity. Based on this, the study hypothesis is to verify the effect of MSC-ad conditioned medium use in in vitro maturation on development rates of bovine embryos. To this end, bovine MSC ad were isolated then cultivated until the passage three (P3) in DMEM culture medium, supplemented with sodium bicarbonate, 10% fetal bovine serum (FBS), 50mL / mL gentamicin. When cultures reached 70% confluency, the medium was replaced with TCM199 supplemented with 0.2 mM pyruvate, 50 ul / ml gentamicin and 10% FBS (IVM medium). The MSC-ad were conditioned with medium TCM199 supplemented for a period of 0 (Control Group), 24 (COND-24 group), 48 (COND-48h group) and 72 hours (COND group-72h), wherein the end of each period, the supernatant medium was removed, filtered, aliquoted and frozen at -20 0 C. The medium was thawed only on MIV day, and supplemented with 0.5 uL of PMSG (concentration 7 IU / ml) and 0.5 uL of HCG. Slaughterhouse ovaries were punctured to obtain oophurus cumulus complexes (COCs) were matured for 24 hours in microdrops of conditioned mediums under mineral oil them incubated in an incubator at 5% CO 2 at 38.5 ° C. Nuclear maturation assessment was performed with 22 hours, then held 15 parthenogenetic activation of only oocytes that exhibited polar body concentration of at least 50 uM ionomycin for 5 minutes, inactivation with TCM199-Hepes 0.03g saturated with BSA, followed by incubation for 3 hours microdroplets 2mM 6-DMAP. After this period, the parthenogenesis were transferred as microdrops to a culture medium in vitro. development rates were evaluated in the second and seventh days after activation. The results were analyzed by ANOVA and Fisher's post-test adopting a significance level of 5%. For groups: Experimental CONTROL, COND-24, COND-48h and 72h-COND, we obtained the following results respectively: 83.7, 77.7, 81.4 and 76.1% of nuclear maturation; 87.5, 86.9, 74 and 80.3 and 23.8% cleavage, 27.5, 18 and 19.6% of blastocyst formation. There was no statistical difference between condinioned experimental groups (p<0.05). However, blastocyst rates were lower when compared with fresh IVM medium (42.1%) (p<0.05). This suggests that the efficiency was affected by the conditioning of the medium or freezing. Future studies should be conducted to assess the levels of growth factors, cytokines and chemokines secreted in IVM medium.
Acesso aberto (Open Access)
Ocorrência de inibidores de glicosidases em cianobactérias e microalgas dos estados do Amapá e Tocantins
(Universidade Federal do Pará, 2015-08-13) SILVA, Vivian Cassia Oliveira da; XAVIER, Luciana Pereira; http://lattes.cnpq.br/6207860145204571
Cyanobacteria are presented as a new source of secondary metabolites for the production of bio-products in many industrial sectors and are used primarily because of its easy cultivation, using few nutritional sources, as well as a large biomass production. Until now we don't have many report in literature of cyanobacteria from amazon, as well as their metabolites and their use in bioproducts. Glycosidases are enzymes of extreme importance as targets for developing drugs that are used for the treatment of various diseases, as well as their inhibitors. This study aimed to identify 24 samples of cyanobacteria and microalgae from the states of Tocantins and Amapá, isolates that produce these inhibitors, as well as extract, fractionate and identify them. Initially, the detection test in petri dishes with esculin the substrate for glycosidase inhibitors has been standardized and the extraction methodology. As a result there was glucosidase inhibitory activity of crude extract and the methanol fraction of four samples (Synechococcus sp, Monoraphydium, P29 and Limnotrix sp), inhibitory activity was detected in the aqueous fractions of any culture. Two methanolic fractions that showed activity was selected for potential assay conducting inhibiting α-glycosidase face with the substrate p-nitrophenyl α-D-glucopyranoside and β-glucosidase to the substrate p-nitrophenyl β-D-glucopyranoside, where both samples had a higher percentage of inhibition for α-glucosidase compared to β-glucosidase.
Acesso aberto (Open Access)
Estudo do crescimento bacteriano na presença de óleos essenciais de Dysphania ambrosioides l. e Ocimum campechianum mill. para avaliar seus potenciais como antissépticos bucais
(Universidade Federal do Pará, 2015-08-31) MOURA, Luiziana Barbosa; SANTOS, Alberdan Silva; http://lattes.cnpq.br/5976702134131016
The aromatic plants like Dysphania ambrosioides (mastruz) and Ocimum campechianum (Alfavaca), that are part of folk medicine in Brazil, have phenylpropanoids and terpenoids compounds in their essential oils as result of secondary metabolism that influence the adaptation and defense of these species in environment; particularly, defense against microrganisms. The objective of this study was to evaluate the antimicrobial activity of essential oils of D. ambrosioides and O. campechianum against pathogenic bacteria mouth. For this they used the disk diffusion method on agar and broth microdilution adapted. The plants were obtained in Santa Izabel do Pará, their leaves were washed and weighed; the essential oil was obtained by hydrodistillation. After, the components of essential oils were identified by gas chromatography-mass spectrometry. Bacteria strains used were: Lactobacillus casei (ATCC 7469), Lactobacillus fermentum (ATCC 9338), Streptococcus mutans (ATCC 25175), Streptococcus oralis (ATCC 10557) and Agregatibacter actinomycetencomitans (ATCC 29522). Bacterial suspensions were prepared for testing and 0.5 McFarland standard. As a positive control we adopted the digluconate of chlorhexidine 0.12%. Inhibition halos were observed for all samples in different concentrations of each essential oil (1%, 5%, 10%, 25%, 50% and 75%). The largest halos were found to A. actinomycetencomitans. In the microdilution test the basil oil inhibited the bacteria S. mutans, the main etiological factor for caries in concentration of 1%; mastruz the oil inhibited L. casei, microorganism that enhances the process of decay in concentrations from 10%; Both oils inhibited the growth of A. actinomycetemcomitans, and can be effective against periodontal disease caused by that pathogen. Plant species of this study produce secondary metabolites classes with potential applications in the development of dental products.
Acesso aberto (Open Access)
Relação entre níveis de células T CD4+ e pressão seletiva nos genes env e vif do HIV-1 subtipos B e C
(Universidade Federal do Pará, 2015-08-31) PEREIRA, Raimundo Cristovão Ferreira; LEAL, Élcio de Souza; http://lattes.cnpq.br/1158983666415285
Previous studies have shown a direct relationship between levels of CD4+ Tlymphocytes and evolutionary rates of HIV-1 (DIAZ et al, 2008; LEMEY et al, 2007; NOSTROM et al, 2014.). Other factors also affect the variability of the env gene: for example function of neutralizing antibodies - Nabs (FROST et al., 2005), the variation in glycosylation sites; (LEAL et al, 2012 LEAL et al., 2008), binding to target cell receptors (i.e, CD4, CXCR4, CCR5), and also the switch from CCR5 to CXCR4 receptor (MILD et al., 2013). Thus, the relationship between viral levels diversification and CD4 + T cells in the env gene can be circumstantial. The vif gene, on the other hand, it is retained and not subject to bias present in the env gene (i.e, glycosylation sites, etc.). Thus, to study the influence of CD4 + T cells levels in HIV variability, the estimate of the selective regimes was used (Nonsynonymous Substitutions - dN and Synonymous Substitutions - dS) by a codon-based model and phylogenetic analysis of unrelated individuals (inter-host). HIV-1 sequences were used of the not-correlated individuals, obtained from the Los Alamos Database. The sequences were separated into CD4+ levels of categories and then analyzed. The analysis revealed no direct correlation between CD4+ T cell levels and evolutionary rates in gp120 and vif gene from HIV-1, subtypes B and C in a population approach.
Acesso aberto (Open Access)
Replicação viral, padrão de expressão de citocinas e cinética de morte celular em cultura primária de células neurais infectadas pelo vírus rocio
(Universidade Federal do Pará, 2015-07-13) SOUTO, Adriano da Paixão; FRANCO, Edna Cristina Santos; http://lattes.cnpq.br/5939607544965550
Arboviruses belonging to the genus Flavivirus (Flaviviridae family) are responsible for considerable morbidity and mortality, may cause severe cases of encephalitis, hemorrhagic fever, hepatitis and febrile disease in vertebrates, including humans. Rocio flavivirus (ROCV) is very important for public health in Brazil, as it represents a serious threat of occurrence of sudden encephalitis outbreaks. The immunopathology of encephalitis caused by flavivirus is not yet fully understood and many aspects involved in modulation of immune responses in the CNS need to be unraveled. Thus, the aim of this study was to analyze the pattern of gene expression of cytokines in primary culture of neural cells when exposed to infection with Rocio. Mixed primary cultures (neuron/glia), obtained from the brains of BALB/C lineage isogenic newborns mice were inoculated with ROCV (MOI equal to 2) on the seventh day of culture and confirmation of infection was made by immunocytochemistry (anti-VROC). Viral replication was quantified in infected primary cultures, depending on the infectious period, by viral titer method. Total cellular RNA was extracted and used for detection of cytokines by real time RT-qPCR techniques. The study showed that primary cultures of neural cells is a good experimental model for the study of CNS infections by Rocio flavivirus. ROCV efficiently infected the primary cultured neural cells leading to cytopathic changes from the 2nd day a.i., when it detected the higher viral titer. The ROCV-infected primary culture survived up to 7 days a.i. and quantification of viral load showed a viral replication kinetics compatible with cell death kinetics of culture infected by ROCV. During the first five days a.i. of the primary culture, there was reduction of IFN-α gene expression, IFN-β, IFN-γ and IL-1β, there was no change in TNF-α expression and there was an increase in TGF-β expression in the 1st, 3rd and 5th day a.i.. The findings of this study suggest that ROCV has the ability to downregulate modulators cytokines of antiviral and inflammatory immune responses and, in this experimental model, immunoregulation exerted by TGF-β predominates over the modulation of inflammatory and antiviral immune responses, larger studies are needed to elucidate immunopathology of CNS infection by ROCV.
Acesso aberto (Open Access)
O papel do colesterol na biossíntese da parede celular de Mycobacterium smegmatis
(Universidade Federal do Pará, 2015-02-26) MARINHO, Victor Hugo de Souza; SENA, Chubert Bernardo Castro de; http://lattes.cnpq.br/8620752020290438
Different Mycobacterium species are causative agents of disease in humans, for example, the tuberculosis. All mycobacteria have a complex cell wall, distinct of others bacteria, conferring specific physic-chemical characteristic to Mycobacterium genus, due to protect against immune system and waterproofing against the intake of much antibiotics. During infection, the bacillus is able to adapter to harsh environment, due to consumption of cholesterol from itself host cell (macrophages) as alternative carbon and energy source. That nutritional aspect has been considered as essential for division of bacilli and consecutive progress of tuberculosis disease. The present study has as objective to evaluate in vitro the modulation of saprophytic Mycobacterium smegmatis cell wall biosynthesis after cholesterol consumption as primordial energy and carbon source. As results, we are found by Thin Layer Chromatography (TLC) that bacillary adaptation to microenvironment with poor nutrient (minimal media – MM) maintained the biosynthesis and accumulation of essential cell wall components, when the growth occurs in presence of someone defined carbon and energy source (glycerol and/or cholesterol). Among them without changes, we analyzed Trehalose Dimicolate (TDM) and the phospholipids (phosphatidylinositol (PI), phosphatidylinositol manosides (PIMs), Cardiolipin (CL) and phosphatidylethanolamine (PE)). Differently of these results, the micolic acid showed representative accumulation, comparing with 7H9 culture, only when the MM was supplemented with glycerol. This result was confirmed by alcohol-acid staining using fluorescent auroamine dye, suggesting some changes in physic-chemistry cell wall properties. On the other hands, the MM culture induced the accumulation of glycopeptidolipids (GPLs), independently of glycerol/cholesterol supplementation. Such disturbance in cell wall biosynthesis also changed the bacillary hydrophobicity in all MM groups, but does not change the resistance and sensibility to antibiotics. Those results clearly show that cell wall biosynthesis might be modulate during nutritional shortage, and such presence or absence of cholesterol, as occurs during infection, does not significantly change the bacillary physiology to become vulnerable for antibiotics. It suggests that such modulations might also occur during infection, maintaining the bacilli available to develop the tuberculosis diseases.
Acesso aberto (Open Access)
Preparação de suportes micro e mesoporosos para imobilização de lipase e aplicação na esterificação do ácido oléico
(Universidade Federal do Pará, 2015-09-29) QUARESMA, Francisco Lucio Barbosa; NASCIMENTO, Luis Adriano Santos do; http://lattes.cnpq.br/3720461233595226
This study aimed to prepare and characterize heterogeneous catalysts using immobilized enzymes in MCM-41 supports and metakaolin. The supports were functionalized with APTES (an amine) for application to the oleic acid esterification reaction with methanol to produce ester. The characterization of the catalyst was made by XRD, FT-IR, physisorption of N2 and spectrometry of UV. The results show that MCM-41 has been effectively functionalized and immobilized enzymes were, however, there was a partial loss of the hexagonal array of such support, while for metakaolin, both functionalization as immobilization did not occur satisfactorily. Using UV spectrometry, it was found that around 80% of the enzymes were effectively immobilized on MCM-41. This biocatalyst (heterogeneous) was tested in the esterification of oleic acid (molar ratio to oleic acid / methanol was 1:15), at a temperature of 30 °C (100 rpm) for 12h. The obtained conversion was 52% of acid mass to ester, indicating that there viability on the use of MCM-41 amine functionalized for the immobilization of lipase, since catalytic activity of the enzyme was preserved. As for metakaolin, the results showed that, despite having been initially some connection enzymes to metakaolin functionalized, UV spectrometry showed that the anchoring enzyme was not effective in the course of 4 hours, however, new methodological approaches to this material may be applied to ensure the efficient functionalization and immobilization.
Acesso aberto (Open Access)
Potencial de produção de antimicrobianos a partir de bactérias isoladas do açaí (Euterpe oleracea)
(Universidade Federal do Pará, 2015-08-17) SALLES, Marina Ludmila Oliveira Conor; SANTOS, Agenor Valadares; http://lattes.cnpq.br/9530734927662735
Açaí is the fruit of a palm tree widely distributed in the Amazon region and has a high microbial load that favors the fruit fermentation process. It is unknown specific studies to investigate the production of antimicrobial substances of biotechnological interest from microorganisms present in acai fruit, which can result in increased value to the fruit. Since food safety has become an increasingly international concern the application of bacteriocins that target food pathogens without adverse toxic effects, have received great attention. The objective of this work is to isolate bacteria from acai, identify the antimicrobial activity of the isolated bacteria, and characterize the extracts of these bacteria as pH, temperature, stability and action spectrum. The selected fruits were collected in Combu Island and Abaetetuba, State of Para, Brazil. These followed for asepsis and pulp removal and dilutions were inoculated in MRS agar and isolated for analysis The antagonism in vitro was performed with the technique of spot-on-the lawn revealing against three bacteria: Corynebacterium sp, Listeria monocytogenes and Bacillus cereus; and with the well diffusion technique. These extracts were characterized for thermal stability (121 ° C / 15 minutes), enzyme sensitivity to trypsin and pH neutralization. Of the thirty-nine bacterial isolates, it was observed antagonistic activity in nineteen of them. Of thesecould be observed twelve showed extracellular antagonist activity. Four extracts showed sensitivity to trypsin, indicating that these may be bacteriocins. Neutralized extracts showed no activity, which indicates better activity at pH acid extracts. Most of the extracts showed activity after being autoclaved, which may be an indication that the extracts have bacteriocins in Classes I and II. This work shows that bacteria isolated from acai have potential for the production of antimicrobial substances.
Acesso aberto (Open Access)
Análise morfológica e molecular dos filamentos das nadadeiras pélvicas do peixe pulmonado Lepidosiren paradoxa
(Universidade Federal do Pará, 2015-12-18) LIMA, Sérgio Queirós; SCHNEIDER, Igor; http://lattes.cnpq.br/4453558334183860
The Lepidosiren paradoxa species belongs to Dipnoi order, along with two genre and are considered true lungfishes. Adult males of L. paradoxa differ from females by the presence of filaments in the pelvic fin. These filaments resemble those found in gills of fish and neotenic salamanders. These filaments are grow and become vascularized during the reproduction period. In this work we tested the hypothesis that the pelvic filament of L. paradoxa share morphological and molecular characteristics with gill filaments. Thus, we performed morphological and molecular analyses of the filaments of the pelvic fins between the dry and rainy seasons. Morphological analysis was perfomed through hematoxylin and eosin (HE) and scanning electron microscopy (SEM). Finally, we quantified gene expression of gill markers by RT-PCR using pectoral fin as reference. The mean length and standard deviation of the filaments during rainy and dry season were 4,31mm of ± 0.186 and 1,63mm ± 0.104, respectively. In the SEM images, we observed with a few cell microvilli and/or microplicae and some smaller cells. In the HE analyzes we found that the filaments have uniform epithelium formed with four layers of cells being filled by connective tissue and finally become more vascularized the rainy season. Molecular analysis through RT-PCR did not show any change when compared to the pectoral fin and between the stations. In conclusion, despite morphological and molecular similarities between gill filaments and pelvic fin filaments, our findings do not support a role for L. paradoxa pelvic filaments in gas exchange.
Acesso aberto (Open Access)
Produção de ésteres etílicos utilizando rejeito da neutralização do processo do refino dos óleos de buriti, maracujá e castanha-do-pará
(Universidade Federal do Pará, 2015-11-27) BRITO, Rogerio da Cunha; NASCIMENTO, Luis Adriano Santos do; http://lattes.cnpq.br/3720461233595226
This study deals with ethyl esters obtainment by using three neutralization soapstock generated from the refining process of Buriti oil, Passion fruit and Brazilian nut (Pará nut). At first, acidification of blots was performed to obtain fatty acids concentration, in order to do so it was used a reagent sulfuric acid leaving to react for 50 min at a temperature of around 85 ° C. Moreover, there was formation of three phases: oil component, fat emulsion and phase acidic water, the supernatant phase (oil component) of interest in the possible presence of fatty acids. Characterization by gas chromatography lees of three samples was performed to quantify the fatty acids present therein, the molar masses were determined and also the acid value. The oil components resulting from the acidification reaction were characterized by a saponification number, acid number and the conversion ratios which have the following values: for burity 96.5%, 94.2% for passion fruit and 90.4% and for Brazilian nut. The acidification of the product (oil component) of burity, passion fruit and Brazilian nut were subjected to esterification reaction, in which ethanol was used as a reactant molar ratio 1:30 (oil: ethanol) and 5% catalyst (in relation to the mass of the oil component). The reaction occurred for 60 minutes at a temperature of about 90 ° C. The same parameters were applied for the three reactions. The characterization of ethyl esters was determined by some quality parameters required by ANP, as acidity index, bulk density, kinematic viscosity at 40 ° C and also the content of ethyl esters present in the sample. The rates of conversion of oil components to ethyl esters showed the following percentage: 93.42% (buriti), 91.71% (passion fruit) and 89.38% (Brazilian nut). Despite the higher conversion into ethyl esters have been observed for the Buriti, samples of passion fruit and Brazilian nutt, also had satisfactory results, as those values revealed that the samples have high potential for reuse serving as raw material for production biodiesel.