Scholarlink

<p>4-Hydroxyisoleucine (4-HIL) holds potential value in the treatment of diabetes. It can be produced by expressing the exogenous isoleucine dioxygenase gene <i>ido</i> in L-isoleucine (Ile) producing <i>Corynebacterium glutamicum</i> strains. But the stable expression of <i>ido</i> on plasmids relies on the usage of antibiotics. To make the harboring of <i>ido</i> independent of plasmid, this study developed a chromosome-engineered strain for synthesizing 4-HIL directly from glucose. First, the <i>ido-cat-ido</i> expressing cassette was inserted into the chromosome of <i>C. glutamicum</i>, and the copy number of <i>ido</i> was increased through chemically inducible chromosome evolution (CIChE). After successive rounds of CIChE by increasing chloramphenicol concentration, 7 copies of <i>ido</i> were integrated in the chromosome of <i>C. glutamicum</i> SE04, and the 4-HIL production reached 20.3 ± 4.99&#xa0;g/L, 3.5-fold higher than the initial strain SC12 harboring two-copies of <i>ido</i>. To cease further homologous recombination, <i>recA</i> was deleted in CIChE strains, but cell growth and 4-HIL production were damaged. Notably, the stability of chromosomally inserted genes in the evolved strain SE04 was confirmed. Ultimately, the evolved <i>C. glutamicum</i> SE04 strain produced 30.3&#xa0;g/L of 4-HIL in a 2-L bioreactor. This study established a plasmid-free strain of <i>C. glutamicum</i> for 4-HIL production, offering new insights into utilizing multi-copy integration methods for producing other valuable biochemical substances in <i>C. glutamicum</i>.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Chemically inducible chromosome evolution of Corynebacterium glutamicum for producing 4-hydroxyisoleucine

  • 期刊论文

  • 发表日期：

    2025年3月25日

查看全文
  • Weiqing Chen,
  • Rui Chen,
  • Feng Shi

摘要

4-Hydroxyisoleucine (4-HIL) holds potential value in the treatment of diabetes. It can be produced by expressing the exogenous isoleucine dioxygenase gene ido in L-isoleucine (Ile) producing Corynebacterium glutamicum strains. But the stable expression of ido on plasmids relies on the usage of antibiotics. To make the harboring of ido independent of plasmid, this study developed a chromosome-engineered strain for synthesizing 4-HIL directly from glucose. First, the ido-cat-ido expressing cassette was inserted into the chromosome of C. glutamicum, and the copy number of ido was increased through chemically inducible chromosome evolution (CIChE). After successive rounds of CIChE by increasing chloramphenicol concentration, 7 copies of ido were integrated in the chromosome of C. glutamicum SE04, and the 4-HIL production reached 20.3 ± 4.99 g/L, 3.5-fold higher than the initial strain SC12 harboring two-copies of ido. To cease further homologous recombination, recA was deleted in CIChE strains, but cell growth and 4-HIL production were damaged. Notably, the stability of chromosomally inserted genes in the evolved strain SE04 was confirmed. Ultimately, the evolved C. glutamicum SE04 strain produced 30.3 g/L of 4-HIL in a 2-L bioreactor. This study established a plasmid-free strain of C. glutamicum for 4-HIL production, offering new insights into utilizing multi-copy integration methods for producing other valuable biochemical substances in C. glutamicum.