Zagazig University Digital Repository
Home
Thesis & Publications
All Contents
Publications
Thesis
Graduation Projects
Research Area
Research Area Reports
Search by Research Area
Universities Thesis
ACADEMIC Links
ACADEMIC RESEARCH
Zagazig University Authors
Africa Research Statistics
Google Scholar
Research Gate
Researcher ID
CrossRef
Characterization and immobilization of purified Aspergillus flavipes L-methioninase: continuous production of methanethiol
Faculty
Science
Year:
2011
Type of Publication:
Article
Pages:
54-69
Authors:
El-Sayed, A. S, Shindia, A. A
DOI:
10.1111/j.1365-2672.2011.05027.x
Journal:
JOURNAL OF APPLIED MICROBIOLOGY WILEY-BLACKWELL
Volume:
111
Research Area:
Biotechnology \& Applied Microbiology; Microbiology
ISSN
ISI:000292884000007
Keywords :
Aspergillus flavipes L-methioninase, enzyme kinetics, immobilization, methanethiol
Abstract:
Aims: To immobilize the purified Aspergillus flavipes L-methioninase on solid carriers for continuous production of methanethiol with high purity, by the enzymatic methods. Methods and Results: The purified L-methioninase was immobilized using different methods, and physicochemical and kinetic studies for the potent immobilized enzyme were conducted parallel to the soluble one. The activity of the purified extracellular enzyme was 1 8-fold higher than intracellular one from submerged cultures of A. flavipes. Among the tested methods, polyacrylamide (42.2\%), Ca-alginate (40.9\%) and chitin (40.8\%) displayed the highest immobilization efficiency. The thermal inactivation rate was strongly decreased for chitin-immobilized enzyme (0.222 s(-1)) comparing to soluble enzyme (0.51 s(-1)). Enzyme immobilization efficiency was greatly improved using 4 0\% glutaraldehyde and 41.6 /6.3 (T/C) as spacers for chitin and polyacrylamide-enzyme conjugates, comparing to their controls. Also the incorporation of lysine, glutathione, cysteine and dithiothreitol as active site protectants significantly enhance the catalytic efficiency of immobilized enzyme. The activity of enzyme was increased by 4.5- and 3.5-fold using glutathione plus DDT and glutathione plus methionine, for chitin and polyacrylamide enzyme, respectively. Conclusion: Chitin enzyme gave a plausible stability till fourth cycle for production of methanethiol under controlled system. Applying GC and HNMR analysis, methanethiol has identical chemical structure to the standard compound. Significance and Impact of the Study: Technically, a new method for continuous production of pure methanethiol, with broad applications, was developed using a simple low expenses method.
Online
PDF
جامعة المنصورة
جامعة الاسكندرية
جامعة القاهرة
جامعة سوهاج
جامعة الفيوم
جامعة بنها
جامعة دمياط
جامعة بورسعيد
جامعة حلوان
جامعة السويس
شراقوة
جامعة المنيا
جامعة دمنهور
جامعة المنوفية
جامعة أسوان
جامعة جنوب الوادى
جامعة قناة السويس
جامعة عين شمس
جامعة أسيوط
جامعة كفر الشيخ
جامعة السادات
جامعة طنطا
جامعة بنى سويف