Journal of Integrative Agriculture ›› 2014, Vol. 13 ›› Issue (8): 1802-1808.DOI: 10.1016/S2095-3119(13)60625-5

• 论文 • 上一篇    下一篇

Construction of a Food-Grade Expression Vector Based on pMG36e by Using an α-Galactosidase Gene as a Selectable Marker

 GU Xin-xi, TAN Jian-xin, TIAN Hong-tao, ZHANG Yu-lan, LUO Yun-bo , GUO Xing-hua   

  1. 1、College of Food Science and Technology, Agricultural University of Hebei, Baoding 071001, P.R.China
    2、College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, P.R.China
    3、Institute of Microbiology, Chinese Academy of Sciences, Beijing 100080, P.R.China
  • 收稿日期:2013-04-17 出版日期:2014-08-01 发布日期:2014-08-02
  • 通讯作者: TIAN Hong-tao, Mobile: 13126883987, E-mail: tht631022@163.com
  • 作者简介:GU Xin-xi, Tel: +86-312-7528423, E-mail: helloguxinxi@163.com; TAN Jian-xin, Tel: +86-312-7528180, E-mail: jianxintan@sina.com
  • 基金资助:

    This work was supported by the National High-Tech R&D Program of China (863 Program, 2006AA10Z317).

Construction of a Food-Grade Expression Vector Based on pMG36e by Using an α-Galactosidase Gene as a Selectable Marker

 GU Xin-xi, TAN Jian-xin, TIAN Hong-tao, ZHANG Yu-lan, LUO Yun-bo , GUO Xing-hua   

  1. 1、College of Food Science and Technology, Agricultural University of Hebei, Baoding 071001, P.R.China
    2、College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, P.R.China
    3、Institute of Microbiology, Chinese Academy of Sciences, Beijing 100080, P.R.China
  • Received:2013-04-17 Online:2014-08-01 Published:2014-08-02
  • Contact: TIAN Hong-tao, Mobile: 13126883987, E-mail: tht631022@163.com
  • About author:GU Xin-xi, Tel: +86-312-7528423, E-mail: helloguxinxi@163.com; TAN Jian-xin, Tel: +86-312-7528180, E-mail: jianxintan@sina.com
  • Supported by:

    This work was supported by the National High-Tech R&D Program of China (863 Program, 2006AA10Z317).

摘要: Construction of a food-grade expression vector for application to lactic acid bacteria (LAB) is of importance for dairy fermentation system. An α-galactosidase (aga) gene encoding an enzyme degrading melibiose was amplified by PCR from the plasmid pRAF800 of Lactococcus lactis NZ9000. The aga gene was introduced into pMG36e to substitute the primary antibiotic selectable marker of pMG36e, resulting in construction of a new food-grade expression vector pMG36-aga. To testify the expression efficiency of exogenous gene in pMG36-aga, a 1.5 kb long α-amylase (amy) gene from Bacillus licheniformis was cloned by PCR and introduced into the plasmid pMG36-aga. The resultant plasimd pMG36-aga-amy was transformed into L. lactis ML23 by electroporation. The positive clones were selected with the medium containing melibiose as the sole carbon source. The selection efficiency of aga was 8.71×103 CFU with a standard deviation of 9.1×102 CFU mg-1 DNA of pMG36-aga. Furthermore, the SDS-PAGE analysis showed that the pMG36-aga-amy expressed a 56.4 kDa protein which was the same as the putative molecular weight of α-amylase. The starch plate assay also indicated that L. lactis ML23 displayed high activity of α-amylase by expressing of amy gene of pMG36-aga-amy.

关键词: food-grade expression vector , Lactococcus lactis , &alpha, -galactosidase gene , amylase gene , pMG36e

Abstract: Construction of a food-grade expression vector for application to lactic acid bacteria (LAB) is of importance for dairy fermentation system. An α-galactosidase (aga) gene encoding an enzyme degrading melibiose was amplified by PCR from the plasmid pRAF800 of Lactococcus lactis NZ9000. The aga gene was introduced into pMG36e to substitute the primary antibiotic selectable marker of pMG36e, resulting in construction of a new food-grade expression vector pMG36-aga. To testify the expression efficiency of exogenous gene in pMG36-aga, a 1.5 kb long α-amylase (amy) gene from Bacillus licheniformis was cloned by PCR and introduced into the plasmid pMG36-aga. The resultant plasimd pMG36-aga-amy was transformed into L. lactis ML23 by electroporation. The positive clones were selected with the medium containing melibiose as the sole carbon source. The selection efficiency of aga was 8.71×103 CFU with a standard deviation of 9.1×102 CFU mg-1 DNA of pMG36-aga. Furthermore, the SDS-PAGE analysis showed that the pMG36-aga-amy expressed a 56.4 kDa protein which was the same as the putative molecular weight of α-amylase. The starch plate assay also indicated that L. lactis ML23 displayed high activity of α-amylase by expressing of amy gene of pMG36-aga-amy.

Key words: food-grade expression vector , Lactococcus lactis , α-galactosidase gene , amylase gene , pMG36e