过量表达羧酸转运蛋白对重组大肠杆菌产丁二酸的影响毕业论文
2022-06-06 22:18:28
论文总字数:16011字
摘 要
丁二酸是优秀的C4平台化合物,广泛应用于医药,食品等领域。生物发酵法产丁二酸凭借其环保,利用可再生生物质资源等优点而备受关注。其中大肠杆菌由于遗传背景清楚、易进行代谢调控,操作简便等优点被作为研究对象,通过对大肠杆菌代谢途径方面进行改造, 如强化丁二酸合成途径、抑制丁二酸旁路代谢途径、激活产丁二酸乙醛酸循环和有氧生产体系等方法,极大地提高了细胞的生长能力和丁二酸的生产效率。
本研究通过PCR技术扩增来源于Escherichia coli K-12 substr. MG1655 菌株的dcuC基因,所扩增的基因带有表达所用的启动子。然后将扩增的目的基因与质粒PMD19T连接,构建成重组质粒,并导入受体菌株AFP111中构建成重组菌。最后与原始菌株AFP111做平行发酵试验。发酵结束后考察每组试验产丁二酸的产量,研究表明:构建的重组菌菌浓约为原始菌菌浓的40%-60%,原始细菌单位细胞产酸能力约为2.0g/L(产酸量/吸光值),构建菌单位细胞产酸能力约为2.5g/L(产酸量/吸光值),原始菌单位细胞产酸能力约为构建菌株的80%,由此可见,构建菌株单位细胞产酸能力略微好。
关键词:dcuc 大肠杆菌 丁二酸
Excess acid transporter protein expression of recombinant E. coli production of succinic acid
Abstract:
Succinic acid is an excellent C4 platform chemical, widely used in medicine, food and other fields. Biological fermentation production of succinic acid, with its environmentally friendly, using renewable biomass resources merit concern. Since E. coli genetic background in which clear and easy to carry on metabolic regulation, and simple operation as the research object, transform E. coli metabolic pathways through, such as strengthening the succinic acid biosynthetic pathway, inhibition of succinate bypass metabolic pathway activation glyoxylate cycle and aerobic capacity succinate production system and other methods, greatly improves the growth and productivity of succinic acid cells.
In this study, PCR amplified from Escherichia coli K-12 substr. DcuC gene MG1655 strains with the amplified gene expression promoter used. Then connect the target gene amplified plasmid PMD19T, the recombinant plasmid, and strain into a recipient AFP111 in the recombinant bacteria. Finally, in parallel with the original strain AFP111 fermentation tests done. After fermentation in each experiment investigated the production of succinic acid production, research shows that: recombinant bacteria bacteria bacteria bacteria concentrated around the original concentration of 40% -60%, of the original unit cell bacterial acid production capacity of about 2.0g / L ( acid production / absorbance) to construct bacteria acid production unit cells of about 2.5g / L (acid production / absorbance), the original bacterial acid production unit cell is about 80% of strains constructed, we can see, building Unit cell strains acidogenicity little better.
Keywords: dcuc coli succinate
目 录
摘 要 I
Abstract II
第一章 绪论 1
1.1丁二酸的性质 1
1.2 丁二酸的应用 1
1.3 丁二酸的市场需求 2
1.4 丁二酸生产方法比较 2
1.4.1 化学合成方法 2
1.4.2 微生物发酵法 3
1.5 研究的意义 4
1.6研究内容及科学依据 5
1.7课题内容 8
第二章 实验材料与方法 9
2.1 实验材料 9
2.1.1 菌株与质粒 9
2.1.2培养基 9
2.1.3主要仪器 9
2.2实验方法 9
2.2.1 转点 10
2.2.2 PCR扩增 10
2.2.3 目的基因与载体连接并转入感受态细胞中 10
2.2.4 血清瓶实验 11
第三章 结果与讨论 12
3.1扩增所需基因 12
3.1.1转点 12
3.1.2 PCR扩增 12
3.1.2.1利用Primer5软件获得引物基因 12
3.1.2.2 PCR体系 12
3.1.2.3程序设定 12
3.1.2.4胶回收 13
3.2 目的基因与载体连接并转入感受态细胞中 13
3.2.1末端平滑DNA3'端加A 13
3.2.2验证 13
3.3血清瓶实验 14
第四章 结论与展望 15
4.1 结论 15
4.2 展望 15
参考文献 16
致 谢 17
第一章 绪论
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