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Separação de compostos com atividade antibacteriana obtidos a partir de cultivos de Streptomyces clavuligerus em meio complexo
(Universidade Federal de São Carlos, 2009-09-01) Bustamante, Maritza Catalina Condori; Pasotto, Marlei Barboza; https://lattes.cnpq.br/7269967957109739
The cephamycin C is a natural cephalosporin produced by Streptomyces clavuligerus, of great importance in the pharmaceutical industry; it is a β-lactam antibiotic that acts as an inhibitor of the cellular wall synthesis. Besides some activity against Gram-negative bacteria, the cephamycin C is resistant to the action of β-lactamase enzymes responsible for the resistance to penicillin. The information available in the literature, on the stages of the industrial production process of cephamycin C is scarcely found, studying the production process and the antibiotic separation is essential to provide technology to the production section. The present study aimed to develop alternative protocols to isolate and purify composites produced by Streptomyces clavuligerus DSM 738, such as the cephamycin C and penicillin, which present antibacterial activity. The sequence of purification stages proposed in this work consisted of: 1) Microfiltration of the broth for the separating cells and insoluble solids; 2) Ultrafiltration for the separation of high molecular weight sub products, such as proteins and enzymes; 3) Use of adsorption process with non ionic resin for the broth clarification; and 4) Finally, the hipotese this work, the adsorption process by ionic exchange, for the separation of composites with antibacterial activity, such as cephamycin C and Penicillin N. On the other hand, cephamycin C is not available in the market, being restricted to the industries that possess the production technology. The biological method of choice for the bacteriological activity test was the Escherichia coli ESS bacteria against all β-lactams. RMN-1H analysis showed that the use of the microfiltration and ultrafiltration are essential as first purification stages. The second purification stage with non ionic resin (Amberlite XAD-4) showed to be efficient on retaining pigments, finally, with this clarified broth, it was possible to separate two major and well defined fractions with antibacterial activity, by the use of an anion exchange resin (QXL of Amershan), utilizing NaCl and CH3COONa as mobile phase. Analysis by RMN-1H showed that the first fraction can represent a cephalosporin molecule, such as cephamycin C, among others compounds.
Estudo da influência do formato das partículas na operação de filtração de gases
(Universidade Federal de São Carlos, 2009-09-01) Azevedo, Sandra Garcia Rodrigues; Aguiar, Mônica Lopes; https://lattes.cnpq.br/0431688649128529; https://lattes.cnpq.br/2263453149577949
Particle morphology is a parameter which deserves great attention in industrial processes. This parameter affect some processes and products like medicines production and cosmetics which are developed by the compaction process, toner cartridges, behavior of aerosol flow of and also the filter cakes formation, among others. Although, the influence of the particle morphology on gas filtration is not well known yet. Because of that, this study aimed to evaluate the influence of particles shape on filter cake formation in gas filtration. Three types of particulate materials were used, all organic, with size distributions very close, similar densities and with different shapes. The materials used were: cassava starch of Yoki brand (volumetric average diameter equal to 14.79 μm), corn starch of the brand Maizena (volumetric average diameter equal to 15.70 μm) and wheat flour of the brand Rosa Branca (volumetric diameter average equal to 27.32 μm). The particle morphology study was done by the analysis of microscopy images on the software Image Pro Plus from Media Cybernetics. The particles shape of cassava starch are very close to the spherical shape with average value for the circularity equal to 0.97, the particles of corn starch have polyhedral shape and circularity equal to 0.85 and the particles of wheat flour have circular flake shape with circularity equal to 0.95. Two types of filter fabric were used as a filter medium, the polypropylene and treated polyester. The filtrations were performed with superficial velocity of 10 cm/s and the cleaning process of the filter medium was done with superficial velocity of 15 cm/s. The time of the filtration experiments was 885 seconds for each one and the cleaning process time was 60 seconds. The results have shown that the filter cake formed by the wheat flour in polyester fabric got the higher specific resistance (k2) of all experiments, with average value of 3.41 x105 s-1 and the lowest porosity. The results using corn starch in polypropylene tissue pointed out the lowest value of specific resistance, with average value equal to 1.21x105 s-1, and also presented a higher porosity of the filter cake. The results have shown that the particle morphology is a very important parameter for the right choosing of the fabric filter, because, for both filter medium tested large differences in pressure drop and also in the efficiency of the cleaning process were observed on the results of the experiments.