一种4-基酸3-基酶突变使得Corynebacterium glutamicum中从葡萄糖中产生4-氨基-3-基酸
Kyoshiro Nonaka1, Tatsuya Osamura2, Fumikazu Takahashi2
1Biological Science Research, Kao Corporation, 1334 Minato, Wakayama, Wakayama, 640-8580, Japan. nonaka.kyoshiro@kao.com.
Microbial cell factories
|August 29, 2023
概括
研究人员设计了Corynebacterium glutamicum以从葡萄糖中产生4-氨基-3-基酸 (4,3-AHBA). 这一进步使得4,3-AHBA的微生物生产成为可能,4,3-AHBA是高性能聚糖聚合物的关键前体.
科学领域:
- 生物技术是生物技术.
- 代谢工程是代谢工程.
- 合成生物学 合成生物学
背景情况:
- 微生物生产芳香化学品为高性能材料提供了一条可持续的途径.
- 4-amino-3-hydroxybenzoic acid (4,3-AHBA) 是一种非蛋白质性氨基酸,是聚糖醇聚合物的关键前体.
- 对4,3-AHBA缺乏有效的微生物生产方法.
研究的目的:
- 使用葡萄糖作为碳源建立4,3-AHBA的微生物生产途径.
- 为了设计Corynebacterium glutamicum用于4,3-AHBA的生物合成.
- 通过酶工程和代谢途径增强,优化4,3-AHBA的产生.
主要方法:
- 在C. glutamicum中,六种不同的4-基酸3-基酶 (PHBHs) 的异质表达.
- 使用葡萄糖对PHBHs进行4,3-AHBA生产的选.
- 从Caulobacter vibrioides (CvPHBH) 获得PHBH的酶工程,通过定位和随机突变发生.
- 增强4-氨基酸 (4-ABA) 生物合成途径.
- 食批量和化学定义的培养介质.
主要成果:
- CvPHBH酶在4,3-AHBA产生方面表现出最高的活性.
- 突变产生了CvPHBH突变 (CvPHBHM106A/T294S) 具有增强的4,3-AHBA生产力.
- 一种重组的C. glutamicum菌株在料批培养中产生了13.5g/L (88mM) 的4,3-AHBA和0.059g/L (0.43mM) 的4-ABA.
- 工程菌株在CGXII介质中从葡萄糖中获得9.8C-mol%的4,3-AHBA,占理论最大产量的12.8%.
结论:
- 工程 PHBH 突变使得 C. glutamicum 中为 4,3-AHBA 生产的人工生物合成途径的建造成为可能.
- 从葡萄糖中实现了4,3-AHBA的格拉姆尺度生产,使生物质衍生前体多样化.
- 这项研究增强了对酶催化区域选择性化和微生物生产有价值的芳香化学物质的理解.
相关概念视频
Amino Acid Catabolism
50
Microorganisms rely on proteins as an essential carbon and energy source, particularly in environments with limited polysaccharides or lipids. However, proteins are too large to cross the plasma membrane unaided, necessitating enzymatic degradation. Microbes secrete extracellular proteases and peptidases that hydrolyze proteins into peptides, which can then be transported across the membrane. Once inside the cell, intracellular proteases degrade these peptides into free amino acids, which...
50
Amino Acid Biosynthetic Pathways
35
Amino acid biosynthesis is essential for cell growth, protein synthesis, and metabolic regulation. Cells generate essential and non-essential amino acids from metabolic intermediates to sustain vital biological functions. These intermediates originate from key metabolic pathways: glycolysis, the tricarboxylic acid (TCA) cycle, and the pentose phosphate pathway. Important precursors include α-ketoglutarate, pyruvate, oxaloacetate, phosphoenolpyruvate, and erythrose-4-phosphate, which...
35
Loss of Carboxy Group as CO2: Decarboxylation of Malonic Acid Derivatives
2.0K
Just like β-keto acids—which upon thermal decarboxylation form ketones—β-dicarboxylic acids undergo decarboxylation to generate monocarboxylic acids with the liberation of carbon dioxide.
2.0K
Fates of Pyruvate
8.7K
Pyruvate is the end product of glycolysis, where glucose is oxidized to pyruvate, simultaneously reducing NAD+ to NADH. Two molecules of ATP are also produced by substrate-level phosphorylation.
In aerobic organisms, pyruvate is metabolized via the citric acid cycle to produce reduced coenzymes NADH and FADH2. These coenzymes are then oxidized in the electron transport chain to produce ATP and, in the process, regenerate the NAD+ and FAD. As seen in some cell types and organisms, fermentation...
In aerobic organisms, pyruvate is metabolized via the citric acid cycle to produce reduced coenzymes NADH and FADH2. These coenzymes are then oxidized in the electron transport chain to produce ATP and, in the process, regenerate the NAD+ and FAD. As seen in some cell types and organisms, fermentation...
8.7K
Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis
3.4K
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...
3.4K
Glycolysis: Preparatory Phase
13.6K
In cellular metabolism (the complete breakdown of glucose to extract energy), glycolysis is the first step. Glycolysis takes place in the cytoplasm of both prokaryotic and eukaryotic cells. Glucose enters heterotrophic cells in two ways. One method is through secondary active transport, where the transport takes place against the glucose concentration gradient. The other mechanism uses a group of integral proteins called GLUT proteins, also known as glucose transporter proteins. These...
13.6K


