食品科学 ›› 2018, Vol. 39 ›› Issue (18): 100-108.doi: 10.7506/spkx1002-6630-201818016

• 生物工程 • 上一篇    下一篇

极端嗜热酸性α-淀粉酶PFA在枯草芽孢杆菌中的高效分泌表达

袁林,曾静*,郭建军,郭浩,杨罡,陈俊   

  1. (江西省科学院微生物研究所,江西?南昌 330096)
  • 出版日期:2018-09-25 发布日期:2018-09-18
  • 基金资助:
    国家自然科学基金青年科学基金项目(31501422);江西省青年科学基金项目(20171BAB214003); 江西省重点研发计划项目(20171BBF60006);江西省科学院资助项目(2017-YCXY-13)

Efficient Secretory Expression of Hyperthermoacidophilic α-Amylase PFA in Bacillus subtilis WB600

YUAN Lin, ZENG Jing*, GUO Jianjun, GUO Hao, YANG Gang, CHEN Jun   

  1. (Institute of Microbiology, Jiangxi Academy of Sciences, Nanchang 330096, China)
  • Online:2018-09-25 Published:2018-09-18

摘要: 为探索极端嗜热酸性α-淀粉酶PFA在枯草芽孢杆菌(Bacillus subtilis WB600)中的高效分泌表达条件,对来源于枯草芽孢杆菌的9?种Sec分泌途径信号肽进行筛选,结果显示信号肽YfkN的引导分泌效率最高。在此基础上,为进一步优化PFA的分泌表达,对信号肽YfkN的Ile3和Gln4进行饱和突变,并比较不同突变体的引导分泌效率。结果表明突变体I3G/Q4R的引导分泌效率最高,重组枯草芽孢杆菌的胞外α-淀粉酶活力高达715?U/mL。重组α-淀粉酶PFA的最适反应pH值为5.0,最适反应温度为100?℃,于100?℃的半衰期长达13?h,并且不依赖于Ca2+。结果表明,采用信号肽I3G/Q4R,极端嗜热酸性α-淀粉酶PFA能够在枯草芽孢杆菌中高效分泌表达,这有利于其在淀粉液化工艺中的应用。

关键词: 极端嗜热酸性α-淀粉酶, 枯草芽孢杆菌, 信号肽, 分泌表达, 饱和突变

Abstract: In this study, we screened 9 secretory (Sec) pathway signal peptides for the production of recombinant hyperthermoacidophilic α-amylase PFA from Pyrococcus furiosus in Bacillus subtilis WB600. The signal peptide YfkN achieved the highest extracellular α-amylase activity. Then we used saturation mutagenesis of Ile3 and Gln4 of the signal peptide YfkN as a novel approach to improve the secretion of PFA. The culture supernatant of the recombinant strain contained the signal peptide I3G/Q4R and had remarkable α-amylase activity (up to 715 U/mL). The purified α-amylase PFA showed maximal activity at pH 5.0 and 100 ℃, and its half-life at 100 ℃ was about 13 h with or without 5 mmol/L Ca2+ added. To the best of our knowledge, we obtained higher yield of PFA in a food-grade host, which may benefit the industrial production and application of PFA.

Key words: hyperthermoacidophilic α-amylase, Bacillus subtilis, signal peptide, secretory expression, saturation mutagenesis

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