[通过构建复合大肠杆菌 (Escherichia coli) 的方法进行β-基-β-甲基黄油酸的全细胞催化合成]
Jiawei Ye1, Hong Xu1, Yaxin Liao1
1Key Laboratory of Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, Jiangsu, China.
Sheng wu gong cheng xue bao = Chinese journal of biotechnology
|September 25, 2025
概括
这项研究开发了一种使用L-氨酸的β-基-β-甲基黄油酸 (HMB) 的绿色生物合成方法. 优化的双酶系统实现了8.60g/LHMB的最大产量,改善了酶活性,并提供了可持续的生产.
科学领域:
- 生物技术是生物技术.
- 酵素工程是什么意思 酵素工程
- 代谢工程是代谢工程.
背景情况:
- 由于有毒试剂和环境问题,β-基-β-甲基酸 (HMB) 的化学合成受到限制.
- 生物合成为HMB生产提供了一种可持续,高效和成本效益的替代方案.
- 酶催化和代谢工程是HMB生物合成的关键策略.
研究的目的:
- 开发一种有效的生物合成策略,用于使用L-氨酸作为基质的HMB生产.
- 描述和设计4-基酸二氧化酶 (Rn4-HPPD) 以提高活性和pH耐受性.
- 优化大肠杆菌中的双酶共表达系统,以提高HMB产量.
主要方法:
- 对L-氨基酸脱氨酶 (PvL-AAD) 和4-基酸酸氧化酶 (Rn4-HPPD) 的表征.
- Rn4-HPPD的局部定向和组合性突变发生,以增强酶活性并改变pH最佳值.
- 优化双酶联合表达比率,发酵条件 (OD600,pH,温度,Fe2+),并在5L发酵器中进行基质养.
主要成果:
- 产生了一种双重突变的Rn4-HPPD (H18R/N302R),与野生类型相比,在pH值分别为5.5和6.5时表现出2.00倍和2.39倍的活性.
- 在大肠杆菌中优化了PvL-AAD和工程Rn4-HPPD的共同表达.
- 在优化的发酵条件下,获得了8.60g/L的HMB最大产量.
结论:
- 改造的Rn4-HPPD突变体显示显著改善活性和更广泛的pH耐受性.
- 开发的双酶联合表达系统和优化的发酵过程使HMB的高效微生物合成成为可能.
- 这项研究为HMB提供了一个有希望的绿色生产策略,在体育营养和疾病预防方面有潜在的应用.
相关概念视频
Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis
4.4K
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...
4.4K
Alkylation of β-Diester Enolates: Malonic Ester Synthesis
4.1K
Malonic ester synthesis is a method to obtain α substituted carboxylic acids from ꞵ-diesters such as diethyl malonate and alkyl halides.
4.1K
Biosynthesis in Bacteria
572
Biosynthesis in bacteria is a fundamental anabolic process that generates essential macromolecules, including proteins, nucleic acids, lipids, and polysaccharides. These macromolecules are critical for cellular growth, replication, and function. The process is tightly regulated and energetically linked to catabolic pathways to ensure optimal resource utilization.Biosynthetic pathways begin with precursor metabolites such as pyruvate, acetyl-CoA, and glucose-6-phosphate derived from glycolysis,...
572
Esters to Carboxylic Acids: Acid-Catalyzed Hydrolysis
4.0K
Hydrolysis of esters under acidic conditions proceeds through a nucleophilic acyl substitution. In the presence of excess water, the reaction proceeds in a reversible manner, forming carboxylic acids and alcohols.
During hydrolysis, the ester is first activated towards nucleophilic attack through the protonation of the carboxyl oxygen atom by the acid catalyst. The protonation makes the ester carbonyl carbon more electrophilic. In the next step, water acts as a nucleophile and adds to the...
During hydrolysis, the ester is first activated towards nucleophilic attack through the protonation of the carboxyl oxygen atom by the acid catalyst. The protonation makes the ester carbonyl carbon more electrophilic. In the next step, water acts as a nucleophile and adds to the...
4.0K


