Characterization of an exoinulinase produced by Aspergillus terreus CCT 4083 grown on sugar cane bagasse

• Autor(a) principal: Coitinho, Juliana B.
• Data de Publicação: 2010
• Outros Autores: Guimarães, Valéria M., Almeida, Maíra N. de, Falkoski, Daniel L., Queiróz, José H. de, Rezende, Sebastião T. de
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: https://doi.org/10.1021/jf1011159; http://www.locus.ufv.br/handle/123456789/19436
• topic: Inulinase; Aspergillus terreus CCT4083; inulin; Agroindustrial residue

Exoinulinase (β- D -fructan fructohydrolase, EC 3.2.1.80) secreted by Aspergillus terreus CCT4083 was obtained using sugar cane bagasse, an agroindustrial residue, as a carbon source. It was further purified from the supernatant culture in a rapid procedure. The enzyme presented 57 kDa on SDS-PAGE and 56 kDa on gel filtration chromatography. Inulin was hydrolyzed by the purified enzyme, yielding D -fructose as the main product. This enzyme showed maximum activity at pH 4.0 and 60 °C and maintained more than 90 and 75% of its original activity at 40 and 50 °C, respectively, after 3.5 h of preincubation. The K M values for inulin, sucrose, and raffinose were 11, 4.20, and 27.89 mM, respectively, and D -fructose was a competitive inhibitor (K i = 47.55 mM). The activation energies for sucrose, raffinose, and inulin were 10.4, 5.61, and 4.44 kcal/mol, respectively. The characteristics of A. terreus exoinulinase were compared to those of inulinases isolated from other organisms. The exoinulinase traits presented especially good thermostability and the ability to produce pure D -fructose, suggesting its application to the production of high-fructose syrup.