食品科学 ›› 2020, Vol. 41 ›› Issue (6): 193-200.doi: 10.7506/spkx1002-6630-20190124-316

• 生物工程 • 上一篇    下一篇

解淀粉芽孢杆菌mtnN基因对其生物合成S-腺苷甲硫氨酸的影响

阮丽英,温志友,魏雪团   

  1. (1.华中农业大学食品科学技术学院,湖北 武汉 430070;2.爱荷华州立大学食品科学与人类营养系,美国 爱荷华州 埃姆斯 50013)
  • 出版日期:2020-03-25 发布日期:2020-03-23
  • 基金资助:
    华中农业大学大北农青年学者提升专项(2017DBN011)

Effect of mtnN Gene on Biosynthesis of S-Adenosylmethionine in Bacillus amyloliquefaciens

RUAN Liying, WEN Zhiyou, WEI Xuetuan   

  1. (1. College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; 2. Department of Food Science and Human Nutrition, Iowa State University, Ames 50013, USA)
  • Online:2020-03-25 Published:2020-03-23

摘要: 为探索解淀粉芽孢杆菌中mtnN基因编码的S-腺苷高半胱氨酸核苷酶对S-腺苷甲硫氨酸(S-adenosylmethionine,SAM)合成的影响,通过基因敲除技术和反义RNA抑制技术构建了针对mtnN基因的系列工程菌株。与出发菌株HZ-12相比,缺失mtnN基因的菌株SAM产量和生物量分别下降了51%和26%,说明完全阻断该基因不利于菌体的生长和产物的合成。进一步通过反义RNA微调抑制mtnN基因的表达,与对照菌株HZ-12/pHY300相比,所构建的反义RNA工程菌HZ-12/pHY-mtnNasRNA-1、HZ-12/pHY-mtnNasRNA-2和HZ-12/pHY-mtnNasRNA-3生物量没有显著性变化,且其SAM产量分别达到14.58、12.27 mg/L和12.49 mg/L,相比对照分别提高了44%、22%和24%。本研究不仅阐释了mtnN基因对SAM合成的影响规律,而且为SAM高产工程菌株的构建提供了新的思路。

关键词: S-腺苷甲硫氨酸, 解淀粉芽孢杆菌, S-腺苷高半胱氨酸核苷酶, 反义RNA, 代谢工程

Abstract: In order to explore the effect of mtnN on S-adenosylmethionine (SAM) synthesis in Bacillus amyloliquefaciens, a series of genetically engineered strains with modifications in the mtnN gene were constructed by gene knockout and antisense RNA suppression technology in this study. Compared with the original strain HZ-12, the SAM yield and biomass of the mtnN-deleted strain decreased by 51% and 26%, respectively, indicating that complete blocking of the mtnN gene is not conducive to cell growth and SAM synthesis. Furthermore, the expression of mtnN was inhibited by antisense RNA fine-tuning. Compared with the control strain HZ-12/pHY300, the biomass of the engineered strains HZ-12/pHY-mtnNasRNA-1, HZ-12/pHY-mtnNasRNA-2 and HZ-12/pHY-mtnNasRNA-3 showed no significant difference from each other, and their SAM yields reached 14.58, 12.27 and 12.49 mg/L, respectively, increasing by 44%, 22% and 24% compared with the control, respectively. This study not only explains the influence of mtnN gene on SAM synthesis, but also provides a new strategy for construction of high-yield SAM producing engineered strains.

Key words: S-adenosylmethionine, Bacillus amyloliquefaciens, S-adenosylhomocysteine nucleosidase, antisense RNA, metabolic engineering

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