کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
35032 45069 2010 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Immobilization of the cross-linked para-nitrobenzyl esterase of Bacillus subtilis aggregates onto magnetic beads
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی بیو مهندسی (مهندسی زیستی)
پیش نمایش صفحه اول مقاله
Immobilization of the cross-linked para-nitrobenzyl esterase of Bacillus subtilis aggregates onto magnetic beads
چکیده انگلیسی

The para-nitrobenzyl esterase (PNBE), which was encoded by pnbA gene from Bacillus subtilis, was immobilized on amino-functionalized magnetic supports as cross-linked enzyme aggregates (CLEA). The maximum amount of PNBE-CLEA immobilized on the magnetic beads using glutaraldehyde as a coupling agent was 31.4 mg/g of beads with a 78% activity recovery after the immobilization. The performance of immobilized PNBE-CLEA was evaluated under various conditions. As compared to its free form, the optimal pH and temperature of PNBE-CLEA were 1 unit (pH 8.0) and 5 °C higher (45 °C), respectively. Under different temperature settings, the residual enzyme activity was highest for the PNBE-CLEA, followed by covalently fixed PNBE without further cross-linking and the free PNBE. During 40 days of storage pried, the PNBE-CLEA maintained more than 90% of its initial activity while the free PNBE maintained about 60% under the same condition. PNBE-CLEA also retained more than 80% activity after 30 reuses with 30 min of each reaction time, indicating stable reusability under aqueous medium.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Process Biochemistry - Volume 45, Issue 2, February 2010, Pages 259–263
نویسندگان
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