کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10235786 | 45058 | 2013 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Improving the acidic stability of a β-mannanase from Bacillus subtilis by site-directed mutagenesis
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
بیو مهندسی (مهندسی زیستی)
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
β-Mannanase can randomly hydrolyze the (1â4)-β-d-mannosidic linkages in mannans, galactomannans and glucomannans, yielding manno-oligosaccharides. In this study, the β-mannanase (MAN) from Bacillus subtilis B10-02 was overexpressed successfully in B. subtilis 168 as a hexa-histidine tagged, secreted protein. The recombinant enzyme BsMAN6H was not stable under acidic conditions, which restricts its use in food and feed industry. We aimed to improve the acid stability of BsMAN6H by changing several surface-exposed amino acid residues to acidic or neutral ones. Among the mutations, the His54Asp resulted in a shift in the optimal pH from 6.5 to 5.5. Accordingly, the acid stability was improved by a factor of a negative potential on the structure surface around the mutated site. Furthermore, the H54D variant showed the enzyme activity up to 3207.82 U/mL in bioreactors using the cheap Kojac powder as substrate. As a result, a bacterial β-mannanase was produced efficiently with increased acid stability, improving its applicability in the animal feed industry.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Process Biochemistry - Volume 48, Issue 8, August 2013, Pages 1166-1173
Journal: Process Biochemistry - Volume 48, Issue 8, August 2013, Pages 1166-1173
نویسندگان
Meijuan Xu, Rongzhen Zhang, Xiangyu Liu, Jinsong Shi, Zhenghong Xu, Zhiming Rao,