کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
686023 | 889058 | 2006 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Purification and properties of a heat-stable exoinulinase isoform from Aspergillus fumigatus
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
تکنولوژی و شیمی فرآیندی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
An inducible extracellular exoinulinase (isoform II) was purified from the extracellular extract of Aspergillus fumigatus by ammonium sulphate precipitation, followed by successive chromatographies on DEAE-Sephacel, Octyl-Sepharose (HIC), Sephacryl S-200, affinity chromatography on ConA-CL Agarose and Sephacryl S-100 columns. The enzyme was purified 75-folds with 3.2% activity yield from the starting culture broth. The purified isoform II was a monomeric 62 kDa protein with a pI value of 4.5. The enzyme showed maximum activity at pH 6.0 and was stable over a pH range of 4.0-7.0, whereas the optimum temperature for enzyme activity was 60 °C. The inulinase isoform II showed exo-inulinolytic activity and retained 72% and 44% residual activity after 12 h at 60 °C and 70 °C, respectively. The inulin hydrolysis activity was completely abolished with 5 mM Hg2+ and Fe2+, whereas K+ and Cu2+ enhanced the inulinase activity. As compared to sucrose, stachyose and raffinose the purified enzyme had a lower Km (1.25 mM) and higher catalytic center activity (Kcat = 3.47 Ã 104 minâ1) for inulin. As compared to exoinulinase isoform I of A. fumigatus, purified earlier, the isoform II is more thermostable and is a potential candidate for commercial production of fructose from inulin.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Bioresource Technology - Volume 97, Issue 7, May 2006, Pages 894-902
Journal: Bioresource Technology - Volume 97, Issue 7, May 2006, Pages 894-902
نویسندگان
Prabhjot Kaur Gill, Rajesh Kumari Manhas, Prabhjeet Singh,