کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4453988 1620820 2015 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effects of metal ions on the catalytic degradation of dicofol by cellulase
ترجمه فارسی عنوان
اثر یونهای فلزی بر تخریب کاتالیزوری دیوکفول سلولاز
کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم محیط زیست علوم زیست محیطی (عمومی)
چکیده انگلیسی

A new technique whereby cellulase immobilized on aminated silica was applied to catalyze the degradation of dicofol, an organochlorine pesticide. In order to evaluate the performance of free and immobilized cellulase, experiments were carried out to measure the degradation efficiency. The Michaelis constant, Km, of the reaction catalyzed by immobilized cellulase was 9.16 mg/L, and the maximum reaction rate, Vmax, was 0.40 mg/L/min, while that of free cellulase was Km = 8.18 mg/L, and Vmax = 0.79 mg/L/min, respectively. The kinetic constants of catalytic degradation were calculated to estimate substrate affinity. Considering that metal ions may affect enzyme activity, the effects of different metal ions on the catalytic degradation efficiency were explored. The results showed that the substrate affinity decreased after immobilization. Monovalent metal ions had no effect on the reaction, while divalent metal ions had either positive or inhibitory effects, including activation by Mn2 +, reversible competition with Cd2 +, and irreversible inhibition by Pb2 +. Ca2 + promoted the catalytic degradation of dicofol at low concentrations, but inhibited it at high concentrations. Compared with free cellulase, immobilized cellulase was affected less by metal ions. This work provided a basis for further studies on the co-occurrence of endocrine-disrupting chemicals and heavy metal ions in the environment.

Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Environmental Sciences - Volume 33, 1 July 2015, Pages 163–168
نویسندگان
, , , ,