کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8331467 1540245 2015 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Agar-agar entrapment increases the stability of endo-β-1,4-xylanase for repeated biodegradation of xylan
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Agar-agar entrapment increases the stability of endo-β-1,4-xylanase for repeated biodegradation of xylan
چکیده انگلیسی
Microbial xylanases, specially endo-β-1,4-xylanase catalyzes the hydrolysis of xylan, is considered one of the most significant hydrolases. It has numerous applications but most extensively is utilized in paper and pulp industry as a bio-bleaching agent. Immobilization technique is comprehensively studied with the expectation of modifying and improving enzyme stability and characteristics for commercial purposes. Currently, matrix entrapment technique is applied to immobilize endo-β-1,4-xylanase within agar-agar gel beads produced by Geobacillus stearothermophilus KIBGE-IB29. Maximal enzyme immobilization yield was achieved at 2.5% of agar-agar concentration. Optimized conditions demonstrated an increase in the optimal reaction time from 05 min to 30 min and incubation temperature from 50 °C to 60 °C with reference to free enzyme whereas; no effect was observed for optimum pH. Entrapment technique uniquely changed the kinetic parameters of immobilized endo-β-1,4-xylanase (Km: 0.5074 mg min−1 to 0.5230 mg min−1 and Vmax: 4773 U min−1 to 968 U min−1) as compared to free enzyme. However, immobilized enzyme displayed broad thermal stability and retained 79.0% of its initial activity at 80 °C up to 30 min whereas; free enzyme completely lost its activity at this temperature. With respect to economic feasibility, the immobilized enzyme showed impressive recycling efficiency up to six reaction cycles.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Biological Macromolecules - Volume 75, April 2015, Pages 121-127
نویسندگان
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