PEP群易位
枯草芽孢杆菌
代谢工程
生物化学
生产过剩
磷酸戊糖途径
代谢途径
生物
双组分调节系统
葡萄糖转运蛋白
柠檬酸循环
糖酵解
化学
酶
磷酸烯醇丙酮酸羧激酶
基因
细菌
生物技术
遗传学
胰岛素
突变体
作者
Yang Gu,Jieying Deng,Yanfeng Liu,Jianghua Li,Hyun‐Dong Shin,Guocheng Du,Jian Chen,Long Liu
标识
DOI:10.1002/biot.201700020
摘要
N ‐acetylglucosamine (GlcNAc) is an important amino sugar extensively used in the healthcare field. In a previous study, the recombinant Bacillus subtilis strain BSGN6‐P xylA ‐ glmS‐ pP43NMK ‐GNA1 (BN0‐ GNA1 ) had been constructed for microbial production of GlcNAc by pathway design and modular optimization. Here, the production of GlcNAc is further improved by rewiring both the glucose transportation and central metabolic pathways. First, the phosphotransferase system (PTS) is blocked by deletion of three genes, yyzE (encoding the PTS system transporter subunit IIA YyzE), ypqE (encoding the PTS system transporter subunit IIA YpqE), and ptsG (encoding the PTS system glucose‐specific EIICBA component), resulting in 47.6% increase in the GlcNAc titer (from 6.5 ± 0.25 to 9.6 ± 0.16 g L −1 ) in shake flasks. Then, reinforcement of the expression of the glcP and glcK genes and optimization of glucose facilitator proteins are performed to promote glucose import and phosphorylation. Next, the competitive pathways for GlcNAc synthesis, namely glycolysis, peptidoglycan synthesis pathway, pentose phosphate pathway, and tricarboxylic acid cycle, are repressed by initiation codon‐optimization strategies, and the GlcNAc titer in shake flasks is improved from 10.8 ± 0.25 to 13.2 ± 0.31 g L −1 . Finally, the GlcNAc titer is further increased to 42.1 ± 1.1 g L −1 in a 3‐L fed‐batch bioreactor, which is 1.72‐fold that of the original strain, BN0 ‐GNA1 . This study shows considerably enhanced GlcNAc production, and the metabolic engineering strategy described here will be useful for engineering other prokaryotic microorganisms for the production of GlcNAc and related molecules.
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