通过基因改造的Erwinia herbicola生产2-Keto-L-Gulonate,这是L-甲酸盐合成中的中间体
Science (New York, N.Y.)
|October 11, 1985
概括
研究人员对Erwinia herbicola进行了改造,以产生2-keto-L-gulonic acid,这是维生素C合成的关键中间体. 这种新陈代谢途径将不同细菌的基因结合起来,用于新型化学品的生产.
科学领域:
- 代谢工程是代谢工程.
- 合成生物学 合成生物学
- 生物技术是生物技术.
背景情况:
- 酸 (维生素C) 合成是一个重要的工业过程.
- 2-基托-L-古隆酸是生产L-亚斯科布酸的重要中间体.
- 目前生产2-keto-L-gulonic酸的方法可能是复杂和昂贵的.
研究的目的:
- 在Erwinia herbicola中设计一种新的代谢途径,用于生产2-keto-L-gulonic酸.
- 为了证明为特殊化学合成创造新的体内路径的可行性.
- 将各种微生物的代谢特征结合到一个单一的宿主中.
主要方法:
- 来自Corynebacterium的立体选择性的2,5-diketo-D-gluconic酸减少酶的识别和净化.
- 使用DNA探针和Corynebacterium基因组图书馆将减少酶基因分离.
- 通过将减少酶基因引入具有trp促进物和核糖体结合部位的多拷贝等离子体上,对Erwinia herbicola进行基因工程.
主要成果:
- Erwinia herbicola成功地被设计成可以生产2-keto-L-gulonic acid的植物.
- 在葡萄糖上生长时,重组微生物将2-keto-L-gulonic酸释放到培养基中.
- 这种工程途径利用了微生物天然生产的2,5-二基托-D-葡萄酸.
结论:
- 专用化学合成的新体内路径是可行的.
- 将来自不同来源的代谢特征结合在一个生物体中是一个可行的策略.
- 这种方法为有效和可持续地生产L-甲酸等重要化学品提供了潜力.
相关概念视频
01:07Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis
Acetoacetic ester synthesis is a method to obtain ketones from alkyl halides and β-keto esters. The reaction occurs in the presence of an alkoxide base that abstracts the acidic proton of the β-keto esters. The step results in an enolate ion which is doubly stabilized. The enolate then reacts with an alkyl halide via the SN2 process to produce an alkylated ester intermediate with a new C–C bond. The hydrolysis of the intermediate, followed by acidification, results in an alkylated β-keto acid.
01:14Alkylation of β-Diester Enolates: Malonic Ester Synthesis
Malonic ester synthesis is a method to obtain α substituted carboxylic acids from ꞵ-diesters such as diethyl malonate and alkyl halides.
01:25Production of Organic Acids
Lactic acid, an important organic acid extensively applied in food, pharmaceutical, and biodegradable polymer industries, is primarily produced via microbial fermentation. This method is favored over chemical synthesis due to its environmental sustainability and capacity for enantiomerically pure product formation. Among various microbial processes, the fermentation of starch-based substrates stands out due to the abundance and renewability of raw materials like corn and potatoes.Hydrolysis of...
01:33Regioselective Formation of Enolates
As depicted in the figure below, the unsymmetrical ketones can form two possible enolates: less substituted or more substituted enolates. Usually, the thermodynamic enolates are formed from the more substituted α-carbon atom, while the kinetic enolates are formed faster by deprotonation from the less substituted position. The thermodynamic enolates have lower energy, so they are more stable. But the energy required to form kinetic enolates is less.
01:19Nitrosation of Enols
The nitrosation reaction is one of the methods of preparing 1,2-diketones. The enol tautomer of the starting ketone reacts with sodium nitrite in hydrochloric acid, generating the 1,2-diketone after hydrolysis.
00:43Dehydration of Aldols to Enones: Acid-Catalyzed Aldol Condensation
As shown in Figure 1, under acidic conditions, the β-hydroxy ketone undergoes dehydration via an E1 elimination reaction to form an enone.