Made available in DSpace on 2017-06-01T18:20:25Z (GMT). No. of bitstreams: 1 Antonio Silva_Dissert.pdf: 1945870 bytes, checksum: dbd64698da19e5ee591cda716481f00d (MD5) Previous issue date: 2007-07-27 / Inquiries had been carried out with submerged fermentation of Rhizopus arrhizus for production of biomass and copolymers chitin and chitosan, using the culture in synthetic medium for Mucoralean and corn steep liquor, as alternative substratum. In this direction, fermentations in Erlenmyers flasks of 250mL had been carried out, contend 50 mL of the media had been inoculated in duplicates with 1% of a suspension of 107/spores/mL, incubated under orbital shaker of 150rpm. To each 24 h had been carried out the content in biomass, glucose consumption, production and characterization of chitin and chitosan, and pH was monitored in elapsing of the studies (96h). The dates had been validated using an analysis for not linear regression, aiming at to explore the potential and versatility of Mucoralean in the production of copolymers. The results obtained with the synthetic medium for Mucoralean had demonstrated a maximum increase of biomass at 72 h of submerged culture. The total of glucose total was consumed by the metabolism of fungus at 96h, with pH 3,2 and consequence period of behavior of cellular decline. The maximum production of chitin and chitosan was 73.5mg and 158 mg, respectively, for gram of biomass with 48 h of cultivation, and maximum speed of growth of µMax 0.036 (h-1) and generation time of 4.6h. On the other hand, the submerged culture of R. arrhizus in corn steep liquor, concentrations of 4, 8 and 16%, as alternative medium and of low cost showed maximum growth of 16.8 g/L, in the concentration of 8% of corn steep liquor, observing a µMax 0.064h-1. High yields of chitin (575 mg/g biomass) and chitosan (416mg/g biomass) could be achieved using the medium containing corn steep liquor at 8%, with 72 h of cultivation, respectively, and pH varying of 6.5 to 8.2. All the isolated copolym rs in both culture media were characterized by index of crystallinity and absorption to the infra-red ray peaks, and were confirmed using the chitin and chitosan standards. The experimental data obtained with chitin and chitosan were validated by the estimation of not linear regression, demonstrating to a good adjustment of the equations and reproducibility. The results with the submerged fermentation of R. arrhizus were compared corn steep liquor at 8% with synthetic medium for Mucoralean fungi, and was observed an increase of 782% and 263% respectively, for chitin and chitosan production. The results obtained suggest R. arrhizus as source of production of the copolymers and as well as the corn steep liquor, considering the nutritional potential and the low cost / Investigações foram realizadas com fermentação submersa de Rhizopus arrhizus para produção de biomassa e dos co-polímeros quitina e quitosana, através do cultivo em meio sintético para Mucorales e milhocina, como substrato alternativo. Neste sentido, foram realizadas fermentações em frascos de Erlenmyers de 250 mL de capacidade, contendo 50 mL dos meios, foram inoculados em duplicatas com 1% de uma suspensão de 107/esporos por mL, incubados sob agitação orbital de 150rpm. A cada 24 h foram realizados conteúdo em biomassa, consumo de glicose, além da estimação e caracterização de quitina e quitosana e o pH foi monitorado no decorrer dos estudos (96h). Os dados obtidos foram validados utilizando uma análise por regressão não linear, visando explorar o potencial e versatilidade dos mucorales na produção dos co-polímeros. Os resultados obtidos com o meio sintético para Mucorales demonstraram um aumento máximo de biomassa com 72 h de cultivo submerso. A glicose foi totalmente consumida pelo metabolismo do fungo com 96h, com pH 3,2 e conseqüente estágio de declínio celular. A produção máxima de quitina e de quitosana por R. arrhizus foi de 73,5 mg e 158 mg, respectivamente, por grama de biomassa em 48 h de cultivo, com velocidade máxima de crescimento de µMax 0,036(h-1)e tempo de geração de 4,6 h. Por outro lado, o cultivo submerso de R. arrhizus em milhocina, nas concentrações de 4,8 e 16%, como meio alternativo e de baixo custo, demonstrou crescimento máximo de 16,8 g/L, na concentração de 8% de milhocina, observando-se µMax 0,064(h-1. Altos rendimentos de quitina (575mg/g de biomassa) e quitosana (416 mg/g de biomassa) foram obtidos com milhocina a 8%, com 72 h de cultivo, respectivamente, e pH variando de 6,5 para 8,2. Todos os copolímeros isolados foram caracterizados pelo índice de cristalinidade e espectro de absorção ao raio infravermelho, confirmando um alto grau de pureza quando comparados aos padrões de quitina e quitosana. Os dados obtidos experimentalmente de produção de quitina e quitosana foram validados pela estimativa de regressão não linear, demonstrando um bom ajuste das equações e reprodutibilidade. Os resultados com a fermentação submersa de R. arrhizus comparando milhocina a 8% com o meio sintético para Mucorales observou-se um aumento considerável de 782% e 263%, respectivamente, para a produção de quitina e quitosana. Assim, os resultados obtidos sugerem R. arrhizus como fonte de produção dos co-polímeros, como também a milhocina, considerando o potencial nutritivo e o baixo custo

Made available in DSpace on 2017-06-01T18:20:47Z (GMT). No. of bitstreams: 1 maria_rosangela_calheiros_alves.pdf: 3828211 bytes, checksum: 8f88ed401400b2866cfb1cd4b380fa2c (MD5) Previous issue date: 2013-05-13 / Chitosan is a natural polymer derived from deacetylation of chitin, derived from the cell wall of fungi and exoskeletons of crustaceans. Due to its chemical structure exhibits properties of chitosan great biotechnological importance with many applications in the environmental fields, agriculture, cosmetics, among others. To check chitosan production by micro-organism, studies were performed using the fungus Mucor subtilíssimus UCP / WFCC 1262 isolated from soil of the savanna of the state of Pernambuco, through full factorial design of 23, by solid state fermentation (FSS) using sweet potato (Ipomoea batatas L.) supplemented with corn steep liquor (industrial waste) and yeast extract, and the response variables biomass and chitosan. For biomass production testing 5 whose composition 3g sweet potato, 8ml milhocina, and not using yeast extract showed the best result with 13.32 g / L of biomass, chitosan and the center point with 120.96 g / 100g biomass with the following composition: 20 g sweet potatoes, 6ml of corn steep liquor, 0.1 ml of yeast extract. The characterization of chitosan showed a degree of deacetylation of 60%. Microbiological chitosan obtained was tested for its environmental capacity in the discoloration of catiônicao dye, methylene blue (MB), process used in the textile industry having variables such as pH, time and temperature. Results obtained with efficiencies discoloration of methylene blue adsorption of the chitosan showed that the pH 6 was more efficient in bleaching AM biosorption with 92.73% under the condition of 8.30 mg to 20 mg of adsorbent in solution PM aqueous, suggesting its use in bioremediation processes of textile effluents. / Quitosana é um polímero natural derivado da desacetilação da quitina, oriundo da parede celular de fungos e exoesqueletos de crustáceos. Devida a sua estrutura química a quitosana apresenta propriedades de grande importância biotecnológica com diversas aplicações nas áreas ambientais, agricultura, cosméticos entre outras. Para averiguar a produção de quitosana por micro-organismo, estudos foram realizados utilizando o fungo Mucor subtilíssimus UCP/WFCC 1262 isolado do solo da caatinga do estado de Pernambuco, através do planejamento fatorial completo de 23, por fermentação semi sólida (FSS), utilizando batata doce (Ipomoea batatas L.) suplementada com milhocina (resíduo industrial) e extrato de levedura, sendo as variáveis respostas produção de biomassa e quitosana. Para a produção de biomassa o ensaio 5 cuja composição: 3g de batata doce, 8ml de milhocina, e não utilizando extrato de levedura apresentou o melhor resultado com 13,32g/L de biomassa, e para quitosana o ponto central com 120,96 g/100g de biomassa com seguinte composição: 20g de batata doce, 6ml de milhocina, 0,1ml de extrato de levedura. A caracterização da quitosana demonstrou um grau de desacetilação de 60%. A quitosana microbiológica obtida foi testada quanto a sua capacidade ambiental no processo de descoloração do corante catiônicao, azul de metileno (AM), empregado na indústria têxtil tendo como variáveis pH, tempo e temperatura . Os resultados obtidos sobre eficiências de descoloração do azul de metileno pela adsorção da quitosana demonstraram que o pH 6 foi mais eficiente na descoloração do AM com a biossorção de 92,73%, na condição 8,30mg do adsorvente para 20 mg de AM em solução aquosa, sugerindo seu emprego em processos de biorremediação de efluentes têxteis.

Terfezia pfeilii is an edible mycorrhizal fungus that thrives in the Kalahari Desert of southern Africa. It is best known by desert dwellers for its flavour and as a source of nutrition. Although the genus Terfezia is generally regarded as being an ectomycorrhizal mycobiont, the exact mycorrhizal type formed by T. pfeilli and its' associated host plants remains uncertain. Discovery of the host plants for T. pfeilii would first be required in order to further investigate the life cycle and cultivation of this truffle. This study focussed on the isolation of mycelia from the ascocarp, optimising the growth conditions of the mycelial cultures, rapid molecular identification of T. pfeilii, investigation of potential helper bacteria and mycorrhizal synthesis experiments. T. pfeilii ascocarps were harvested from the Spitskop Nature Reserve in Upington, South Africa. Ascocarps were successfully identified using both morphological and molecular methods. Despite the delayed growth mostly caused by contaminating microorganisms, the isolation of T. pfeilii mycelia culture was successful. Molecular techniques were used to confirm the identity of the pure culture. Further studies were conducted on ways to improve the growth conditions of the mycelial culture on Fontana medium. An optimum temperature of 32°C, the addition of Bovine Serum Albumin as a nitrogen source and a pH of 7.5 significantly improved the growth of T. pfeilii in vitro. A rapid PeR-based molecular method was developed to speed up the identification of T. pfeilii. Specific primers that can exclusively amplify the ITS region of T. pfeilii were designed and used to identify both the ascocarps and the mycelial culture. The specificity of these primers was confirmed by their inability to amplify DNA from the isolates of contamining fungi obtained during the isolation process. Molecular comparison was made to confirm the reclassification of South African samples of T. pfeilii as Kalaharituber pfeilii as proposed by Ferdman et al.,(2005). However, in this study, the name T. pfeilii has been retained. A total of 17 bacterial isolates were obtained from the fruiting bodies of T. pfeaii and these were tested for stimulation of mycelial growth in vitro, indole production and phosphate solubilising capabilities. Bacterial isolates that showed potential to be Mycorrhization Helper Bacteria (MHB) were identified as Paenibacillus sp., Bacillus sp. and Rhizobium tropici. Selected plant seedlings were inoculated with T. pfeilii cultures or ascocarp slurry in order to re-establish the mycorrhizal association. After 8 months, light microscopy observations revealed an endomycorrhizal type association between Cynodon dactylon and T. pfeilii. This was confirmed with molecular analysis using specific T. pfeilii ITS primers. After 15 months, molecular methods confirmed Acacia erioloba as another host plant. These results have provided essential information paving the way for further investigation into the life cycle and biology of the Kalahari truffle. / KMBT_363 / Adobe Acrobat 9.53 Paper Capture Plug-in