Isolamento e seleção de fungos filamentosos termofílicos produtores de celulases, xilanases e celobiose desidrogenase com potencial para sacarificação do bagaço de cana-de-açúcar

• Autor(a) principal: Rosa, Isabel Zaparoli [UNESP]
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/110639
• topic: Microbiologia; Fungos termofilicos; Celulase; Bagaço de cana; Thermophilic fungi

Owing the growing demand for fuels, research is being done with the aim of obtaining new types of biofuels from renewable resources. Cellulosic ethanol, obtained from residual biomass from agricultural and agro-industrial processes has been considered as a complement of ethanol production by decreasing the need for expansion of sugarcane areas. However, the viability of the process requires the development of technologies saccharification of lignocellulosic materials by biochemical route, such as enzymatic or abiotic methods. The filamentous fungi are a group of microorganisms that produce (secretory) of enzymes involved in the degradation of biomass. The enzymes cleave hemicellulolytic and cellulolytic complex connections that form polymers of polysaccharides present in the biomass releasing fermentable hexoses and pentoses to ethanol, however, accessory enzymes such as cellobiose dehydrogenase are important in the process efficiency. This design aimed at the isolation of thermophilic fungal strains with the ability to secrete those enzymes, as well as the enzyme preparations to obtain stability to pH and temperature variations that occur during the hydrolysis step. 32 fungal strains capable of growing at temperatures between 45 and 60 °C were isolated, five were selected to continue the following work steps (Thermomyces lanuginosus S1, T. lanuginosus S3, Rasamsonia emersonii S10, R. emersonii BC and T. lanuginosus FZI) as a function of experiencing growth at 60 °C. Among these strains, the highest activities of β-glucosidase (52 U/g) and endoglucanase (579 U/g) were obtained from the culture medium of strain R. emersonii S10 in 240h for both enzymes. The best activity FPase (cellulase that hydrolyzes filter paper) was presented by the fungus T. lanuginosus S1 in 168h of cultivation, having produced 262.8 U/g enzyme. The R. emersonii S10 was the only fungus that showed detectable avicelase production of enzymes (9.2 U/g) and ...