ICB - Instituto de Ciências Biológicas
URI Permanente desta comunidade
Navegar
Navegando ICB - Instituto de Ciências Biológicas por Por Orientador "Bataus, Luiz Artur Mendes"
Agora exibindo 1 - 3 de 3
Resultados por página
Opções de Ordenação
Item Caracterização de celulases e xilanases produzidas por Streptomyces sp. cultivado em resíduos lignocelulósicos(Universidade Federal de Goiás, 2012-10-27) Cunha, Carolina Cândida de Queiroz Brito; Bataus, Luiz Artur Mendes; http://lattes.cnpq.br/3739169267521003An actinomycete strain, isolated from cane sugar bagasse (CSB), identified as Streptomyces sp was selected for its ability to produce cellulases. The production of cellulases was analyzed by submerged fermentation by cultivation on minimal medium (MM) containing CSB, wheat bran (WB) or carboxymethylcellulose (CMC) as carbon source, and yeast extract (YE) as nitrogen source. The results show that WB was the best inducer of CMCases (2.0 U.mL-1). Aiming to analyze the production of cellulases and xylanases kinetics, the isolate was inoculated in minimal medium containing 0.5% (w/v) WB and maintained for 12 days at 45°C under constant agitation of 180 rpm. The highest yield of Avicelase was observed after 264 h of cultivation (5.646 Uml-1), after 144 h for CMCase (3.872 Uml-1), after 144 h for FPase (0.0947 Uml-1) and after 288 h for Xylanase (92.40 Uml- 1). Culture supernatants with maximum activity of Avicelase, CMCase, Fpase and Xylanase were analyzed for optima pH and temperature of the respective enzymes. The highest enzyme activities were detected at pH 7.0 at 35°C for Avicelase, pH 4.5/75°C for CMCase, pH 5.5/45°Cfor FPase and pH 5.5/70°C for Xylanase. The enzymes retained more than 70% of the initial activity after 2 h incubation at 50°C. The profile proteins analyzed by zymogram demonstrated a set of secreted cellulases (37, 21 and 17 kDa) and xylanases (39, 21, 18 and 17 kDa) when grown on FT for 144 h. The saccharification assay with CSB as substrate showed that the enzyme complex was able to release 19% of glucose and 62.9% of xylose.Item Caracterização do gene ftsH de Streptomyces sp Y7(Universidade Federal de Goiás, 2002-12-14) Paixão, Cinthia Ferreira da; Bataus, Luiz Artur Mendes; http://lattes.cnpq.br/5637230378599476The actinomycets are Gram-positive bacterias, aerobic with rich DNA in G+C (larger than 60%) and immobile. They are found practically in all the environment, forming ramified filaments or hyphae that persist in the mycelium form. The Streptomyces constitutes 90% of the isolated actinomycets of the soils, in spite of they are also found in aquatic atmospheres and interior of some plants. They stand out for the diversity of production of hidrolytics enzymes and antibiotics, 70% of the know antibiotics are produced by those microorganisms. Aiming to clone genes with biotechnological interest, a genomic libraries of the Streptomyces sp Y7 isolated of the soil of Cerrado was constructed. After the analyses of the sequences of the genomics libraries of Streptomyces sp Y7, it was selected a plasmid named pFS8, that displayed similarity with ftsH genes. The ftsH gene encodes a metalloprotease ATPase and Zn+2 dependent, belongs to the AAA family (ATPases associated with a variety of cellular activities). It is involved with several cellular functions such as secretory proteins export and degradation of transcriptional factors (sigma 32 and Lambda CII). The data of sequencing showed that the ftsH gene was incomplete. In order to characterize if the product of this gene showed biological activity, it was made tests to evaluate the functionality of the fusions proteins in an ftsH-negative E.coli strain AR3291. AR3291 cells transformed with this plasmid showed a general growth advantage upon the cells AR3291. The protein produced did not present toxicant effects for cells AR3289, which had normal ftsH gene. The truncated protein obtained was also analyzed to prediction of the structure “coiled-coil”, that is common to the other FtsH studied, and the results showed those truncated proteins did nor form “coiled-coil” structure. We also tested whether fusion proteins decreased or inhibited the defective transfer of citosolic proteins.Item Análise de celulases e xilanases por fungo isolado a partir do bioma cerrado(Universidade Federal de Goiás, 2013-05-06) Pereira, Douglas Endrigo Perez; Faria, Fabrícia Paula de; Bataus, Luiz Artur Mendes; http://lattes.cnpq.br/5637230378599476; Bataus, Luiz Artur Mendes; Faria, Fabrícia Paula de; Jesuíno, Rosália Santos Amorim; Fonseca, Marcio José PoçasLignocellulosic biomass is constituted by cellulose, hemicellulose and lignin in the plant cell walls. The conversion of lignocellulose to fermentable sugars mainly depends on the action of a complex of enzymes that hydrolyze cellulose and hemicellulose. This study was to analyze the production of cellulases and xylanases by fungi isolated from soil and decaying material in Cerrado. Initially, the fungi were analyzed for cellulase production capacity among the fungal cellulase-producing fungus capable of producing the highest levels of cellulase was selected for the experiments of xylanase and cellulase production by submerged fermentation and biochemical analysis of the enzyme secreted. Among the isolated fungi, fungus called IFBMD01 was that higher activity of cellulase in the supernatant when cultivated with wheat bran as carbon source. This was identified as Aspergillus cf niger. The enzymes studied with their respective results were: FPase with better production time of 7 days, showing activity of 0.10 U / mL, optimum pH 5.5, optimum temperature of 60 ° C; CMCase with better time production 6 days, showing activity of 8.19 U / mL, pH optimum of 5, optimum temperature of 70 º C; Avicelase with better production time of 9 days, showing activity of 0.01 U / mL, pH optimum of 5.5 and optimum temperature of 60 ° C; xylanase, with better production time 3 days, showing activity of 35.5 U / mL, and the optimum pH of 5 and the optimum temperature of 50 ° C, the β-Glycosidase, with higher production on the sixth day showing activity of 0.98 U / mL, with the optimum pH 5 and optimum temperature of 60 ° C. The activity of β-glucosidase showing in the culture supernatant was influenced by the ions Mn2 +, NH4, K +, Mg2 +, Ca2 +, Ba2 +, Al3 +, Na +, and Co2+, as well as EDTA, glucose, xylose and cellobiose. In the culture supernatant of the fungus A. niger IFBMD01 grown on FT for 3 and 6 days protein bands were visualized with activity against xylan and CMC molecular weight be 30 to be 66 kDa.