Characterization of an Exoinulinase Produced by Aspergillus terreus CCT 4083 Grown on Sugar Cane Bagasse
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- 作者：Juliana B. Coitinho ; Valria M. Guimares ; Mara N. de Almeida ; Daniel L. Falkoski ; Jos H. de Queirz ; Sebastio T. de Rezende
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2010
- 出版时间：July 28, 2010
- 年：2010
- 卷：58
- 期：14
- 页码：8386-8391
- 全文大小：822K
- 年卷期：v.58,no.14(July 28, 2010)
- ISSN：1520-5118
文摘
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 KM values for inulin, sucrose, and raffinose were 11, 4.20, and 27.89 mM, respectively, and d-fructose was a competitive inhibitor (Ki = 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.