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- ItemEstudo químico de metabólitos especiais produzidos por fungos endofíticos de Moringa oleifera Lam(Universidade Federal de Mato Grosso, 2019-09-27) Braun, Poliana Cardoso; Teles, Helder Lopes; 101.296.138-94; http://lattes.cnpq.br/5902911518497333; Teles, Helder Lopes; 101.296.138-94; http://lattes.cnpq.br/5902911518497333; Guimarães, Salomão Lima; 925.317.505-25; http://lattes.cnpq.br/9250168755115649; Camargo, Maria Jose de; 558.955.141-20; http://lattes.cnpq.br/1658847665468138Increased resistance of microorganisms to commonly used antibiotics has been a major concern in both human health and agriculture. In Brazil, over-resistant microorganisms (sepsis) in hospitals are the leading cause of death from generalized hospital infections, being considered a public health problem. In agriculture the fight against phytopathogenic microorganisms has been causing several environmental impacts due to the improper and exaggerated use of agrochemicals. Therefore, the present work aims to isolate and elucidate molecules with antibiotic potential from endophytic fungi associated with the Moringa oleifera Lam. species.32 fungi strains were isolated from different parts of the plant (leaf, stem, seed and flower). Endophytes were grown for seven days on a small scale with 05 Petri dishes in PDA (PotatoDextrose-Agar) medium, randomly cut and transferred with culture medium to 500 mL Erlenmeyers flask with 100 mL ethyl acetate. After 24 hours of extraction on the orbital shaker at 190 rpm, and one hour of sonication, the organic phase was subjected to vacuum evaporator rotation, obtaining the crude extracts. These were solubilized with methanol:water (95:5) at a concentration of 20 mg/mL, subjected to solid phase extraction in Sep-Pak cartridge (1g silica C-18) and analyzed by Ultra Fast Liquid Chromatography - Photodiode Detector Array (UFLCPDA) in exploratory gradient method [analytical C18 column, methanol:water (5:95) to (100:0), 40']. Subsequently, 21 strains were tested and subjected to antimicrobial agar diffusion assays against five strains of bacteria (Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 13883, Pseudomonas aeruginosa ATCC 27853 and Enterococcus faecalis ATCC 29292), and five yeast fungi (Candida albicans ATCC 10231, Candida krusei ATCC 6258, Candida tropicalis ATCC 25922, Candida glabrata ATCC 90030 and Candida parapsilosis ATCC 40058), human pathogens, respectively, cultured at 37ºC for 24h (bacteria) and 48h (fungi), and thereafter, aqueous suspensions were prepared from the grown colonies following the MacFarland 0.5 (fungus) and 1.0 (bacteria) standards. The preliminary chromatogram analysis allowed the selection of the fungi MOS02, MOF32, MOC07 and MOC09 for continuity of the work. These were again cultivated on a larger scale in PDA (50 Petri dishes), yielding 1493.5 mg (crude extract); 638.0 mg; 1040.5 mg; and 604.0 mg, respectively, after extraction with EtOAc and drying. There were no promising results regarding antibiosis tests against human pathogens.
- ItemProspecção de metabólitos especiais com potencial antimicrobiano produzidos por fungos endofíticos associados à gramínea Axonopus Leptostachyus (Flüggé) Hitchc (Poaceae)(Universidade Federal de Mato Grosso, 2020-03-31) Neponuceno, Ricardo Aparecido Rodrigues; Teles, Helder Lopes; 101.296.138-94; http://lattes.cnpq.br/5902911518497333; Teles, Helder Lopes; 101.296.138-94; http://lattes.cnpq.br/5902911518497333; Ribeiro, Tereza Auxiliadora Nascimento; 030.639.426-00; http://lattes.cnpq.br/1866455078888688; Oliveira, Camila Martins de; 270.381.258-26; http://lattes.cnpq.br/0897793846591143Endophytic fungi contribute considerably to the production of bioactive metabolites of great economic value and with several applications, such as antibiotics and agrochemistry. In this context, the present work aimed to perform the isolation, purification and structural elucidation of secondary metabolites produced by endophytic fungi associated with Axonopus leptostachyus, aiming at the search for substances with potential antimicrobial action. In this way, 64 endophytes isolated from A. leptostachyus, were submitted to assays to evaluate antimicrobial activity, against 5 strains of bacteria and 5 of human pathogenic candida, semi-quantified and classified into groups of high (AIA), medium (MAI) and low (BAI) inhibitory activity. Additionally, six selected endophytes were also evaluated for the detection of possible antagonists of the phytopathogen Corynespora cassicola. The results of the bioassays added to the multivariate analysis allowed the selection of the endophytic fungi with the best potential for obtaining the bioactive metabolites, with Microsphaeropsis arundinis (P21) being the only one that showed excellent activity in relation to all tests. Against pathogenic bacteria and candida, the fungi Talaromyces varreculosus (P24), Gongronella butleri (P48), Penicillium javanicum (P70) and the unidentified endophyte (P4) stood out with the best antimicrobial activities. The tests also identified that Cladosporum flabelliforme (P5) and Neocosmospora strita (P28) showed excellent activities against pathogenic candida and phytopathogen, while Fusarium succisae (P59) and Fusarium oxysporum (P61) stood out only with activity for C. cassicola. After the bioassays, the endophytes with the best potentials were submitted to cultivation in PDA (Potato Dextrose Agar) and minimal medium, in a reduced and enlarged scale. In the PDA medium, the endophytes were grown in 100 mL of medium (5 Petri dishes) under incubation at 37 °C for 15 to 23 days. Pieces with PDA and mycelia were randomly cut and macerated for 24 h with 150 mL of ethyl acetate (EtOAc). The EtOAc phase was vacuum filtered, concentrated in a rotary evaporator and dried in an air jet, obtaining the crude extracts EtOAc. In the minimal medium, the fungi grew in duplicate of 200 mL under incubation and orbital shaking for 20 days. Then, the micellar suspension was filtered, partitioned with EtOAc, and dried to obtain the crude extracts. In sequence, the extracts from the screening and growth stages on a larger scale were solubilized and analyzed using HPLC-PDA (High-Performance Liquid Chromatography – Photodiode Array) and 1H NMR (Proton Nuclear Magnetic Resonance). After analysis, the P5, P21 and P28 endophytes were chosen for the chromatographic fractionation of their extracts, aiming at the isolation of the compounds responsible for the detected activities. The isolated substances were analyzed using 1H and 13C NMR spectroscopy, gCOSY, gHMBC and gHSQC for the identification or elucidation of their structures. The fractionation of the EtOAc extract of C. flabelliforme (P5) resulted in the isolation of a compound in Tr 26 min. (FR1.16- 17.fim.3), not yet identified. The study of M. arundinis (P21) allowed the identification of a benzolactonic dimer (1), an unprecedented molecular structure for the genus Microsphaeropsis. For the fungus N. striata (P28), substances extracted from the PDA medium were isolated, such as the monorden (radicicol), a lactonic derivative of resorcylic acid (2), and the compounds in fractions FR4.fim.4, FR6.1, FR6.3, FR6.5 and FR1.precipitate, not yet identified, as well as a substance extracted from the minimal medium, under study for structural identification (3).
- ItemTratamento de efluente contendo metomil e imidacloprido em reator hermético fotolítico solar(Universidade Federal de Mato Grosso, 2019-03-06) Balsan, Lucas; Barbosa, Domingos Sávio; 702.907.921-34; http://lattes.cnpq.br/6896725721269796; Barbosa, Domingos Sávio; 702.907.921-34; http://lattes.cnpq.br/6896725721269796; Teles, Helder Lopes; 101.296.138-94; http://lattes.cnpq.br/5902911518497333; Seolatto, Araceli Aparecida; 038.549.169-73; http://lattes.cnpq.br/1495882445078650In line with the mandatory possession of the decontamination yard for individuals and legal entities that practice aerial spraying of pesticides, provided for in Normative Instruction N° 02 established in Brazil by the Ministry of Agriculture, Livestock and Supply (MAPA) in 2008, this study developed and evaluated an improved hypothetical model of the yard installation required, called the retention reservoir, solarization and evaporation of wash water from agricultural aircraft spray tanks. The system which was characterized by a hermetically sealed photolytic system to ensure occupational safety, with the use of solar radiation as a renewable energy source, which aims to mitigate contamination risks and energy costs in the treatment of effluents with pesticides. Sunlight and heat can activate and accelerate the degradation of metomil and imidacloprid pesticides in mixed solution. The experiment compared the reference samples in the dark at 24±1 °C (R) with treatments carried out in three reactors, which consisted of a hermetic dark reactor (EH), with matt black dyed aluminum cap to enhance radiation absorption. and heat generation, an airtight light reactor (CH), open for light transmittance through a clear borosilicate glass cover, to promote the greenhouse effect and a light open reactor (CA), exposed to the atmosphere and radiation to mimic the constructive aspect required by the MAPA Normative Instruction, which submits the effluents to evaporation. The contribution of radiation on the thermodynamic variation of the reactors was evaluated according to the inherent peculiarities of their constructive aspects, using thermocouple sensors for the effluent thermometry in static regime. The environmental variables of temperature and relative humidity, and dewpoint temperature were measured by means of a datalogger sensor, and the illuminance was read through a lux meter for later conversion of lux to radiation in the power unit. in W.m-2 , for comparison with data obtained from a weather station near the experiment. High performance diode array liquid chromatography was used to determine the residual concentrations of pesticides obtained by averaging triplicate samples of each pesticide in the mixed solution for 13 days of effluent solarization. The tests showed that the EH reactor does not degrade the studied pesticides and the AC reactor concentrates them as the effluent evaporates, forming a more toxic effluent than the original, which generates occupational health risks and biotic environment. The CH reactor was the only one effective in reducing concentrations, with low first and second order kinetic constants and satisfactory determination coefficients, with half-life estimates of 68 and 17 days for metomil and imidacloprid, respectively. The results demonstrate that direct photolysis is not efficient in reducing the concentrations of the studied pesticides and suggest that methods based on photothermocatalytic oxidation processes, using visible light sensitive photocatalysts and with positive effect on thermal increment efficiency, be included in the process required by the decontamination yard.