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Stability of endoglucanases from mesophilic fungus and thermophilic bacterium in acidified polyols.
Chong, Barrie Fong; Harrison, Mark D; O'Hara, Ian M.
Afiliación
  • Chong BF; Syngenta Centre for Sugarcane Biofuels Development, Queensland University of Technology, GPO Box 2432, 2 George Street, Brisbane, Queensland 4001, Australia.
  • Harrison MD; Syngenta Centre for Sugarcane Biofuels Development, Queensland University of Technology, GPO Box 2432, 2 George Street, Brisbane, Queensland 4001, Australia. Electronic address: md.harrison@qut.edu.au.
  • O'Hara IM; Syngenta Centre for Sugarcane Biofuels Development, Queensland University of Technology, GPO Box 2432, 2 George Street, Brisbane, Queensland 4001, Australia.
Enzyme Microb Technol ; 61-62: 55-60, 2014.
Article en En | MEDLINE | ID: mdl-24910337
Recent developments in chemical pretreatments of lignocellulosic biomass using polyols as co-solvents (e.g., glycerol and ethylene glycol) at temperatures less than 100°C may allow the effective use of thermostable and non-thermostable cellulases in situ during the saccharification process. The potential of biomass saccharifying enzymes, endoglucanases (EG) from a thermophilic bacterium (Thermotoga maritima) and a mesophilic fungus (Trichoderma longibrachiatum), to retain their activity in aqueous buffer, acidified glycerol, and acidified ethylene glycol used as co-solvents at pretreatment temperatures at or below 100°C were examined. The results show that despite its origin, T. longibrachiatum EG (Tl-EG) retained 75% of its activity after exposure to 100°C for 5 min in aqueous buffer while T. maritima EG (Tm-EG) retained only 5% activity. However, at 90°C both enzymes retained over 87% of their activity. In acidified (0.1% (w/w) H2SO4) glycerol, Tl-EG retained similar activity (80%) to that obtained in glycerol alone, while Tm-EG retained only 35%. With acidified ethylene glycol under these conditions, both Tl-EG and Tm-EG retained 36% of their activity. The results therefore show that Tl-EG is more stable in both acidified glycerol and ethylene glycol than Tm-EG. A preliminary kinetic study showed that pure glycerol improved the thermal stability of Tl-EG but destabilized Tm-EG, relative to the buffer solution. The half-lives of both Tl-EG and Tm-EG are 4.5 min in acidified glycerol, indicating that the effectiveness of these enzymes under typical pretreatment times of greater than 15 min will be considerably diminished. Attempts have been made to explain the differences in the results obtained between the two enzymes.
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Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Proteínas Bacterianas / Trichoderma / Proteínas Fúngicas / Celulasa / Thermotoga maritima Idioma: En Revista: Enzyme Microb Technol Año: 2014 Tipo del documento: Article País de afiliación: Australia Pais de publicación: Estados Unidos

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Proteínas Bacterianas / Trichoderma / Proteínas Fúngicas / Celulasa / Thermotoga maritima Idioma: En Revista: Enzyme Microb Technol Año: 2014 Tipo del documento: Article País de afiliación: Australia Pais de publicación: Estados Unidos