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  

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

作　　者：阮丽英 温志友[2] 魏雪团[1] RUAN Liying;WEN Zhiyou;WEI Xuetuan(College of Food Science and Technology,Huazhong Agricultural University,Wuhan 430070,China;Department of Food Science and Human Nutrition,Iowa State University,Ames 50013,USA)

机构地区：[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　　处：《食品科学》2020年第6期193-200,共8页Food Science

基　　金：华中农业大学大北农青年学者提升专项(2017DBN011)。

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/pHYmtnNasRNA-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。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/pHYmtnNasRNA-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.

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 

分 类 号：TS201.3[轻工技术与工程—食品科学]