بررسی حذف فنل توسط پراکسیداز ترب کوهی تثبیت شده

نوع مقاله: مقاله پژوهشی

نویسندگان

1 استاد، دانشکده مهندسی شیمی و نفت، دانشگاه صنعتی شریف، تهران

2 دانشجوی کارشناسی ارشد بیوتکنولوژی، دانشکده مهندسی شیمی و نفت، دانشگاه صنعتی شریف، تهران

3 دانشجوی کارشناسی ارشد مهندسی صنایع غذایی، دانشکده مهندسی شیمی و نفت، دانشگاه صنعتی شریف، تهران

چکیده

در این تحقیق کاربرد پراکسیداز ترب کوهی (HRP) تثبیت شده در کپسول‌های آلژینات به‌منظور حذف فنل و نیز شرایط بهینه برای تثبیت HRP در آلژینات تعیین شد. شرایط بهینه برای ژله‌ای شدن به‌ترتیب 0/75 و 4/5درصد حجمی وزنی برای آلژینات سدیم و کلسیم کلرید شش آبه به‌دست آمد. بر اثر تثبیت آنزیم، منحنی فعالیت آنزیمی بر اساس pH به‌گونه‌ای تغییر کرد که مقادیر فعالیت نسبی در pH‌های اسیدی و بازی بیشتر شد. همچنین نتایج نشان داد که درصد فعالیت باقیمانده آنزیم محبوس شده مستقل از غلظت آنزیم مورد استفاده است. علاوه‌ بر این، نتایج نشان داد که غلظت آنزیم برای حذف فنل در غلظت فنلی مشخصی دارای مقدار بهینه است که با فراتر رفتن از این مقدار تغییر چندانی در بازده حذف مشاهده نشود. بررسی پیشرفت واکنش با زمان برای آنزیم محبوس شده و آنزیم آزاد نشان داد که در غلظتهای برابر، حذف فنلی برای آنزیم محبوس شده اندکی کمتر است. با این حال، نتایج نشان داد که کپسول‌ها تا چهار دوره بدون تغییر قابل ملاحظه در فعالیت باقیمانده آنها قابل استفاده هستند. نسبت بهینه پراکسید هیدروژن به فنل برای غلظت فنل 2 تا 10 میلی مولار، 0/94 تا 1/15 به‌دست آمد و نشان داده شد که این نسبت وابسته به غلظت فنل است.

کلیدواژه‌ها


عنوان مقاله [English]

Phenol Removal by Immobilized Horseradish Peroxidase

نویسندگان [English]

  • Iran Alemzadeh 1
  • Siyamak Nejati 2
  • Sepideh Motamed 3
1 Prof., Chemical and Petroleum Engineering Dept., Sharif University of Technology, Tehran
2 Grad. Student of Biotechnology, Chemical and Petroleum Eng. Dept., Sharif University of Technology, Tehran
3 Grad. Student of Food Industrial Eng., Chemical and Petroleum Eng. Dept.,Sharif University of Technology, Tehran
چکیده [English]

Horseradish peroxidase was successfully encapsulated in calcium alginate for phenol removal. The optimum gelation condition was found to be 0.75%w/v of sodium alginate solution and 4.5% w/v of calcium chloride hexahydrate. Upon immobilization, the pH profile of enzyme activity changed as it showed a higher relative value in basic and acidic solutions. It was also observed that enzyme activity retention of encapsulated HRP was independent of enzyme concentration. Besides, for each phenol concentration, there would be an enzyme concentration beyond which it had no significant effect on phenol removal. Investigation of phenol removal with time for both encapsulated and free enzymes showed that the encapsulated enzyme had a lower efficiency compared to the same concentration of the free enzyme; however, the capsules were reusable up to four cycles without any changes in their retention activity. The optimum ratio of hydrogen peroxide/phenol was found to depend on phenol concentration and that it varied from 0.94 to 1.15 for phenol concentrations between 2-10 mM.

کلیدواژه‌ها [English]

  • Horseradish peroxidase
  • alginate
  • Gelation
  • Encapsulation
  • Phenol
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