کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8360027 | 1542327 | 2015 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Characterization of a thermostable raw-starch hydrolyzing α-amylase from deep-sea thermophile Geobacillus sp.
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
A deep-sea thermophile, Geobacillus sp. 4j, was identified to grow on starch and produce thermostable amylase. N-terminally truncated form of Geobacillus sp. 4j α-amylase (Gs4j-amyA) was fused at its N-terminal end with the signal peptide of outer membrane protein A (OmpA) of Escherichia coli. The enzyme was over-expressed in E. coli BL21 with a maximum extracellular production of 130 U/ml in shake flask. The yield of the transformant increased 22-fold as compared with that of the wild strain. The recombinant enzyme purified to apparent homogeneity by metal-affinity chromatography, exhibited a molecular mass of 62 kDa. It displayed the maximal activity at 60-65 °C and pH 5.5. Its half-life (t1/2) at 80 °C was 4.25 h with a temperature deactivation energy of 166.3 kJ/mol. Compared to three commonly used commercial α-amylases, the Gs4j-amyA exhibited similar thermostable performance to BLA but better than BAA and BSA. It also showed a universally efficient raw starch hydrolysis performance superior to commercial α-amylases at an acidic pH approaching nature of starch slurry. As a new acidic-resistant thermostable α-amylase, it has the potential to bypass the industrial gelatinization step in raw starch hydrolysis.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Protein Expression and Purification - Volume 114, October 2015, Pages 15-22
Journal: Protein Expression and Purification - Volume 114, October 2015, Pages 15-22
نویسندگان
Tao Jiang, Menghao Cai, Mengmeng Huang, Hao He, Jian Lu, Xiangshan Zhou, Yuanxing Zhang,