生物技术通报 ›› 2015, Vol. 31 ›› Issue (5): 206-213.doi: 10.13560/j.cnki.biotech.bull.1985.2015.05.032

• 研究报告 • 上一篇    下一篇

乙酸对重组大肠杆菌BL21产酶的影响及作用机理研究

戴琨, 王腾飞, 郝昭程, 汤丹丹, 刘红娟, 王瑞明   

  1. (齐鲁工业大学生物工程学院,济南 250353)
  • 收稿日期:2014-08-14 出版日期:2015-05-18 发布日期:2015-05-18
  • 作者简介:戴琨,女,硕士研究生,研究方向:微生物酶技术;E-mail:daikun1989@126.com
  • 基金资助:
    山东省科技发展计划(2011GGB01160)

Study on Effects of Acetic Acid on Enzyme Production of the Recombinant Escherichia coli BL21 and Its Action Mechanism

Dai Kun, Wang Tengfei, Hao Zhaocheng, Tang Dandan, Liu Hongjuan, Wang Ruiming   

  1. Department of Biology Engineering, QILU University of TechnologyJinan 250353)
  • Received:2014-08-14 Published:2015-05-18 Online:2015-05-18

摘要: 旨在研究发酵过程中产生的乙酸对重组大肠杆菌BL21(DE3)/pET15b-TreS的生长以及重组海藻糖合酶基因表达的影响,并对其作用机理进行探讨。通过外源添加乙酸(钠)的方法,研究了乙酸钠对重组菌BL21(DE3)/pET15b-TreS生长曲线的影响;利用环境扫描电子显微镜,观察了重组菌形态的变化情况;通过测定菌液的电导率值变化、菌液上清中OD260的变化,研究了乙酸(钠)对菌体细胞膜渗透性、完整性的影响;通过测定菌液上清中β-半乳糖苷酶的活性检测了乙酸钠对菌体细胞内膜的影响;利用荧光分析法检测了乙酸对菌体膜蛋白构象的影响;采用SDS-PAGE电泳研究了乙酸钠对菌体重组海藻糖合酶表达量的影响。结果表明,乙酸(钠)会对重组菌的生长产生一定的抑制作用,可以导致菌体细胞的表面出现凹陷、皱缩;并会影响细胞膜的渗透性、完整性,使得一些细胞内容物发生泄漏;影响细胞膜上的膜蛋白构象,对膜的结构造成一定程度的破坏;对重组海藻糖合酶的表达产生影响。乙酸(钠)对重组菌菌体的生长及重组海藻糖合酶基因的表达有影响,并且菌体细胞膜是其作用的一个靶点。

关键词: 乙酸, 重组大肠杆菌, 抑菌机理, 细胞膜, 海藻糖合酶

Abstract: Our objective is to study the effects of acetic acid from fermentationon the growth of the recombinant Escherichia coli BL21(DE3)/pET15b-TreS as well as the expression of the recombinant trehalose synthase gene, and the action mechanism was also discussed. Firstly, we studied the effect of acetic acidon the growth of recombinant Escherichia coli by experiments with adding acetic acid(sodium acetate), and observed the morphological changes of recombinant bacteria by using environmental scanning electron microscope. Then, the effects of acetic acid(sodium acetate)on the permeability and the integrity of cell membrane were studied through the determination of electrical conductivityof the brothand the changes of OD260 of the supernatant. The activity of β-galactosidase in the supernatant was measured to determine the effect of sodium acetate on intracellular membrane, and then the influence of acetic acidon the conformation of membrane protein by using fluorescence analysis were detected. Finally, the effect of sodium acetate on the expression of the recombinant trehalose synthase gene by SDS-PAGE was studied. Results showed that the acetic acid(sodium acetate)could have certain inhibition effects on the recombinant bacteria growth, and caused cell surface to be depressed and shrinkage. The permeability and integrity of cellmembranes were affected by the acetic acid(sodium acetate), leading some substances in cells to leak out. And experiments also revealed that the acetic acid could make effects on the conformation of the membrane proteinin the cell membrane,which caused a certain degree of damages to the membrane structure. SDS-PAGE analysis suggested that the sodium acetate had impacts on the expression of the recombinant trehalose synthase gene. The acetic acid(sodium acetate)was confirmed to affect the cell growth and the expression of the recombinant trehalose synthase gene, and the cell membrane was a target of its function.

Key words: acetic acid, Recombinant Escherichia coli, antimicrobial mechanism, cell membrane, trehalose synthase