کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1191937 963594 2006 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Hydrolysis of sucrose by invertase immobilized on nylon-6 microbeads
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Hydrolysis of sucrose by invertase immobilized on nylon-6 microbeads
چکیده انگلیسی

A commercial extracellular invertase (EC 3.2.1.26) from Saccharomyces cerevisiae has been inmobilized by covalent bonding on novel microbeads of nylon-6 using glutaraldehyde. The enzyme was strongly bound on the support, immobilized with an efficiency factor of 0.93. The biocatalyst showed a maximum enzyme activity when immobilized at pH 5.0, but optimum pH activity for both immobilized and free invertases was 5.5. The optimum temperatures for immobilized and free enzymes were 60 and 65 °C, respectively. Kinetic parameters were determined for immobilized and free invertases: Vmax values were 1.37 and 1.06 mmol min−1 mg−1, respectively. The Km and Ki values were 0.029 and 0.71 M for immobilized invertase and 0.024 and 0.69 M for free invertase. It was found that the thermal stability of the immobilized invertase with regard to the free one increased by 25% at 50 °C, 38% at 60 °C and 750% at 70 °C. The immobilized biocatalyst was tested in a tubular fixed-bed reactor to investigate its possible application for continuous sucrose hydrolysis. The effects of two different sugar concentrations and three flow rates on the productivity of the reactor and on the specific productivity of the biocatalyst were studied. The system demonstrated a very good productivity up to 2.0 M sugar concentration, with conversion factors of 0.95 and 0.97, depending on sucrose concentration in the feeding. This approach may serve as a simple technique and can be a feasible alternative to continuous sucrose hydrolysis in a fixed bed reactor for the preparation of fructose-rich syrup.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Food Chemistry - Volume 99, Issue 2, 2006, Pages 299–304
نویسندگان
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