Enzimas fibrolíticas de Humicola grisea [manuscrito]: produção, caracterização e seus efeitos sobre a digestibilidade in vitro do capim Marandu, casquinha de soja, feno de Tifton 85 e forragem de milho

• Ano de defesa: 2009
• Autor(a) principal: CYSNEIROS, Cristine dos Santos Settimi
• Orientador(a): ULHOA, Cirano Jose
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Goiás
• Programa de Pós-Graduação: Mestrado em Ciência Animal
• Departamento: Ciências Agrárias - Veterinaria
• País: BR
• Palavras-chave em Português: ANKOM; caracterização bioquímica; forragens; fungo termofílico; resíduos agroindustriais; soluções enzimáticas; 1. Digestibilidade in vitro 2. Humicola grisea 3. Aditivos Enzimáticos 4. Forragens 5. Resíduo Agroindustrial
• Palavras-chave em Inglês: Agroindustrial byproducts; ANKOM; biochemical characterization; enzymatic solutions; forages; thermophilic fungus
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::PRODUCAO ANIMAL
• Link de acesso: http://repositorio.bc.ufg.br/tede/handle/tde/328

The objective of this work was to produce and characterize four multi enzyme complexes from the fungus Humicola grisea var. thermoidea, maintained for 96 hours at 42oC in growth media containing different carbon sources: Marandu grass; soybean seedcoats; Tifton 85 hay; and corn forage. Different amounts of cellulase, xylanase and -glucosidase enzymes were obtained depending on the different carbon sources. Cellulase presented increased activity in temperatures between 40ºC and 50ºC. The observed optimum temperature range for xylanase and β-glycosidase was from 50ºC and 60ºC. Optimum pH for cellulase activity was 6.0 when fungus growth occurred in Tifton hay, corn forage, and soybean seedcoats. When the enzyme was obtained from medium containing Marandu grass, optimum enzyme activity occurred at pH 5.5. Regardless of the carbon source, xylanase activity was higher at pH 6.0. As for β-glucosidase, optimum activity was observed at pH 5.5 for Tifton media as compared to pH 6.5 for corn and soybean containing media. For grass Marandu, the activity of the enzyme was maximum in the range 5.5 to 6.5. Cellulase produced from all growth media were maintained stable after incubation for 60 minutes at 39°C. Xylanase presented thermal stability during 240 minute incubation period at 50°C. Activity stability of β-glycosidase varied according to carbon source and presented 66.7 to 125.75% activity at 50°C for 240 minutes.