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Thesis (Ph.D. (Biochemistry)) --University of Limpopo, 2010 / A heavy-metal resistant bacterium (GM 16) was isolated from a South African antimony mine, and the non-viable cells of the isolate were used to investigate its biosorption capacity for Cd(II) and Cu(II) from aqueous solution in a batch process. The biosorption of both metals were found to be influenced by factors such as pH of the metal solution, initial metal ion and biomass concentrations, rate of agitation, presence of other metal ions, contact time of the metal solution with the biomass and temperature. The initial biosorption of both Cd(II) and Cu(II) was rapid and equilibrium was reached within 1 hour of biomass contact with the metal solutions. The sorption of both metal ions was higher in weak acid than in strong acid conditions and the optimum pH values for Cd(II) and Cu(II) biosorption were 7 and 6, respectively. The presence of the other metal ions in the metal adsorption media influenced the biosorption of both Cd(II) and Cu(II). Mg2+ ions decreased the uptake of Cu(II) and Cd(II) by 4.7 and 6.5 %, respectively. Whereas K+, Na+ and Ca2+ ions increased the uptake of Cd(II) by 12.3, 8.7, and 3.2 %, respectively, they slightly decreased the sorption Cu(II) (2-6.4 %). Increases in initial metal ion (40-120 mg L-1) and biomass (0.8-4.8 g L-1) concentrations enhanced the sorption of Cd(II) and Cu(II) by GM16 biomass. When the biomass concentration was increased from 0.8 to 4.8 g L-1, the biosorption capacity of Cd(II) increased from 5.5 to 14.5 mg g-1 while that of Cu(II) increased from 2.8 to 14.7 mg g-1 at optimum pHs and a temperature of 40 °C. Maximum adsorption of both metals occurred at an agitation rate of 100 rpm. In addition, increase in initial metal ion concentration from 40-120 mg L-1 increased the initial adsorption rates (h) and the equilibrium metal sorption capacity (qe) of the GM 16 biomass from 6.07 to 16.51 mg g-1 for Cu(II) and 8.9 to 17.9 mg g g-1 for Cd(II). Adsorption equilibrium data for both metal ions fitted well to the Langmuir adsorption model with high correlation coefficients (r2 > 0.90) but the data for Cu(II) could also be described by the Freundlich adsorption model. Increase in temperature from 25-40 °C only caused marginal increases in maximum metal sorption capacities (qmax). The results on kinetic analysis showed that the biosorption processes of Cd(II) and Cu(II) ions by the non-viable GM 16 cells followed pseudo-second order kinetic model betterthan the pseudo-first order model, although the calculated metal sorption capacities obtained with the model were overestimated. The calculated thermodynamic parameters showed that the biosorption of Cd(II) and Cu(II) ions was feasible, spontaneous and slightly endothermic for Cd(II) but slightly exothermic for Cu(II) under examined conditions. Based on 16S ribosomal DNA sequencing, the bacterial isolate (GM 16) was identified as a Bacillus sp. and is closely related to Bacillus thuringiensis and Bacillus cereus strains. The biosorption capacity of the non-viable GM 16 biomass was higher than the biosorption capacity reported for the viable GM 16 cells, 65 % of Cd(II) was removed by non-viable biomass whereas 48 % was removed by the viable biomass. For the biosorption of Cu(II), the % metal ion adsorbed for the non-viable GM 16 cells was slightly higher than the % adsorbed for the viable cells although not statistically significant. Only 67 % of Cu(II) was removed by the non-viable cells whereas 65 % was removed by the viable cells. / National Research Foundation

Submitted by Mario BC (mario@bc.ufrpe.br) on 2017-02-21T14:31:39Z No. of bitstreams: 1 Penellope Teles Viveiros da Silva.pdf: 2225516 bytes, checksum: 71cbc5ed73dc00ce129b5c93f8fe83c3 (MD5) / Made available in DSpace on 2017-02-21T14:31:39Z (GMT). No. of bitstreams: 1 Penellope Teles Viveiros da Silva.pdf: 2225516 bytes, checksum: 71cbc5ed73dc00ce129b5c93f8fe83c3 (MD5) Previous issue date: 2016-07-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The cultural characterization of bacterial isolates is usually the first step in the process of getting the isolated and evaluation of biodiversity. These evaluations are important and allow for a preliminary screening of isolated by separating them into groups genera, for example. This study aimed to characterize phenotypically bacterial strains derived from root nodules of forages: Desmanthus pernambucanus and Mimosa tenuiflora grown in fertilized soil or not. Samples of soil for cultivation of plants in the screened greenhouse were collected in the cities of Arcoverde, Ibimirim and Serra Talhada, Pernambuco. The isolates were characterized as the time of growth of colonies, determine the shape and diameter, high transparency, exopolysaccharides production and coloration of the colonies, change of pH. They determined the number and biomass of nodules, production indoles and phenotypic characterization of bacterial isolates. Cultural assessment, were seen as key features: rapid growth time, flat elevation, exopolysaccharides production of low to moderate color ranging from cream to white and smooth surface. Legumes had nodulation in the three soils in the absence or presence of manure. Manuring does not increase the number of nodules of Mimosa tenuiflora plants, but increases the number of nodules Desmantus pernambucanus. The bacterial strains are capable of producing indole compounds without the addition of tryptophan. / A caracterização cultural dos isolados bacterianos geralmente é a primeira etapa do processo de obtenção dos isolados e avaliação de sua biodiversidade. Estas avaliações são importantes e permitem a seleção preliminar de isolados, separando-os em grupos de gêneros, por exemplo. A realização deste estudo teve como objetivo caracterizar fenotipicamente estirpes bacterianas oriundas de nódulos radiculares das espécies forrageiras: Desmanthus pernambucanus e Mimosa tenuiflora cultivadas em solos adubados ou não. As amostras de solos para cultivo das plantas em estufa telada foram coletadas nos municípios de Arcoverde, Ibimirim e Serra Talhada, Pernambuco. Os isolados foram caracterizados quanto ao tempo de crescimento de colônias, determinação da forma e diâmetro, elevação, transparência, produção de exopolissacarídeos e coloração das colônias, alteração do pH do meio. Foram determinados o número e a biomassa de nódulos, produção de compostos indólicos e caracterização fenotípica dos isolados bacterianos. Na avaliação cultural, foram observadas como principais características: tempo de crescimento rápido, elevação plana, produção de exopolissacarídeos de pouca a moderada, coloração variando de creme a branca e superfície lisa. As leguminosas tiveram nodulação nos três solos na ausência ou presença de esterco. Adubação com esterco não aumenta o número dos nódulos das plantas Mimosa tenuiflora, porém aumenta o número de nódulos das Desmantus pernambucanus. Os isolados bacterianos são capazes de produzir compostos indólicos sem adição de triptofano.

Submitted by Deyse Queiroz (deysequeirozz@hotmail.com) on 2018-05-22T15:00:44Z No. of bitstreams: 1 JESSÉ MALVEIRA GOMES - DISSERTAÇÃO PPGHT - 2017.pdf: 1522466 bytes, checksum: cc3a2a2cb3b9b312f031097d4500a8df (MD5) / Made available in DSpace on 2018-05-22T15:00:44Z (GMT). No. of bitstreams: 1 JESSÉ MALVEIRA GOMES - DISSERTAÇÃO PPGHT - 2017.pdf: 1522466 bytes, checksum: cc3a2a2cb3b9b312f031097d4500a8df (MD5) Previous issue date: 2017-03 / O milho é uma das culturas mais produzida e importante no mundo, sendo utilizada na alimentação humana e animal. O Brasil é um dos maiores produtores desse grão, sendo o terceiro maior produtor do mundo. Apesar de uma produção elevada, a produtividade é comprometida pela ação de insetos pragas, sendo a Spodoptera frugiperda Smith a de maior atuação nessa cultura. Em meio a esse desafio, o uso constante de inseticidas é utilizado com intuito de minimizar as perdas nas lavouras, porém, ocasionando grandes impactos ambientais, bem como a contaminação de trabalhadores rurais. Uma das estratégias viáveis e promissoras na supressão de pragas tem sido o manejo integrado de pragas (MIP), que tem como alicerce o uso isolado ou consorciado de técnicas de controles de pragas, sendo o controle biológico uma das ferramentas mais sustentáveis do ponto de vista ecológico. Desta forma, o presente trabalho teve como objetivo avaliar a toxicidade da cepa bacteriana 358.1 isolada do petróleo e o sobrenadante da cultura de células sobre o controle de lagartas de 2º e 3º instares de S. frugiperda, comparando as taxas de mortalidade e efeitos sobre seu desenvolvimento e com inseticidas químicos comerciais. O experimento consistiu de duas etapas, o primeiro ensaio foi realizado com lagartas de 3º instar com três diluições diferentes da cepa 358.1, sobrenadante da cultura de células, solução salina como controle negativo e o inseticida fenpropatrina como controle positivo. No segundo ensaio utilizou-se lagartas de 3º e 2º instares, a cultura celular da cepa 358.1 em sua concentração total (4 x 108 UFC/mL), seu sobrenadante da cultura, como controle negativo água destilada e testemunha positiva o produto comercial flubendiamida. Os experimentos com a cepa 358.1, sobrenadante da cultura de células e os produtos químicos testados não resultaram em uma taxa de mortalidade de S. frugiperda significante, porém, a cepa 358.1 e seu sobrenadante da cultura resultaram no aumento da duração da fase larval e em distúrbios morfofisiológicos do inseto, ocasionando, inclusive, no surgimento de adultos com asas atrofiadas, sendo desta maneira, promissores para à realização de novos testes. / Corn is one of the most produced and important crops in the world, utilized for human and animal feeding. Brazil is one of the top producers of this grain, being the third biggest producer worldwide. Despite the great production, the productivity is compromised due to the activity of insect pest. Because of this challenge, the continuous use of insecticides is done aiming to minimize lost in the crops. However, it causes major environmental impact and it is also contaminating rural workers. One of the viable and promising strategies to the pest suppression has been the pest integrated management (PIM), which is based on the use of isolated or consortium of pest controlling techniques, the biological control being one of the most sustainable tools in an ecological perspective. Therefore, the present study had the goal of evaluating the toxicity of the 358.1 bacterium strain isolated from the oil and supernatant of the cell culture under control of caterpillars from 2nd and 3rd instars of S. frugiperda, comparing the death rates and effects on their development, and also comparing with commercial chemical insecticides. The experiment consisted in two stages; the first assay was done with 3rd instar caterpillar with three different dilutions from the 358.1 strain, supernatant of the cell culture, saline solution as negative control, and fenpropatrina insecticide as positive control. On the second assay, 3rd and 2nd instars caterpillars were used, the cell culture from the 358.1 strain on its total concentration (4 x 108 UFC/mL), supernatant of the cell culture, distilled water as negative control and flubendiamida, a commercialized product, as the positive control. The experiments with the 358.1 strain, supernatant of the cell culture and the tested chemical products didn’t show a significant death rate for S. frugiperda, however, the 358.1 strain and supernatant of the cell culture resulted in an increase in the larval phase duration and on morphophysiological disturbs on the insect, resulting yet in the emergence of adults with atrophied wings, thus being promising to the realization of new tests.