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).
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Item 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/0000-0002-2690-2841Kojic 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.Item 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/9530734927662735Açaí 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.Item 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/0000-0002-2690-2841Cyanobacteria 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.