Scholarlink

Abstract <p>L-valine holds wide-ranging applications in medicine, food, feed, and various industrial sectors. <i>Escherichia coli</i>, a pivotal strain in industrial L-valine production, features a concise fermentation period and a well-defined genetic background. This study focuses on mismatch repair genes (<i>mutH</i>, <i>mutL</i>, <i>mutS</i>, and <i>recG</i>) and genes associated with mutagenesis (<i>dinB</i>, <i>rpoS</i>, <i>rpoD</i>, and <i>recA</i>), employing a high-glucose adaptive culture in conjunction with metabolic modifications to systematically screen for superior phenotypes. This approach enhances the spontaneous survival rate of stress cells and facilitates the enrichment of positive mutations. Leveraging a multi-fragment seamless recombination technique, we successfully assembled the <i>ilvBN</i>, <i>ilvC</i>, <i>ilvE</i>, and <i>ilvD</i> pathway enzyme genes, transforming <i>E. coli</i> from a non-producer into a proficient L-valine producer capable of generating up to 6.62&#xa0;g/L. Through a synergistic application of self-evolution engineering and metabolic engineering strategies, the engineered <i>E. coli</i> strain exhibited significantly enhanced tolerance and demonstrated heightened accumulation of L-valine.</p> Key points <p>•<i> The innovation centered on mutated genes and mismatch repair genes</i></p> <p>•<i> By integrating modification with adaptive culture, a superior phenotype was attained</i></p> <p>•<i> Double plasmids expressing enzymes for L-valine production in E. coli were obtained</i></p> Graphical Abstract <p></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

Screening of high glucose tolerant Escherichia coli for L-valine fermentation by autonomous evolutionary mutation

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2025年1月21日

查看全文
  • Li Zhang,
  • Zhijie Cheng,
  • Jing Jiang,
  • Xinyu Zhou,
  • Longjun Han,
  • Lei Yang,
  • Jian Gao

摘要

Abstract

L-valine holds wide-ranging applications in medicine, food, feed, and various industrial sectors. Escherichia coli, a pivotal strain in industrial L-valine production, features a concise fermentation period and a well-defined genetic background. This study focuses on mismatch repair genes (mutH, mutL, mutS, and recG) and genes associated with mutagenesis (dinB, rpoS, rpoD, and recA), employing a high-glucose adaptive culture in conjunction with metabolic modifications to systematically screen for superior phenotypes. This approach enhances the spontaneous survival rate of stress cells and facilitates the enrichment of positive mutations. Leveraging a multi-fragment seamless recombination technique, we successfully assembled the ilvBN, ilvC, ilvE, and ilvD pathway enzyme genes, transforming E. coli from a non-producer into a proficient L-valine producer capable of generating up to 6.62 g/L. Through a synergistic application of self-evolution engineering and metabolic engineering strategies, the engineered E. coli strain exhibited significantly enhanced tolerance and demonstrated heightened accumulation of L-valine.

Key points

• The innovation centered on mutated genes and mismatch repair genes

• By integrating modification with adaptive culture, a superior phenotype was attained

• Double plasmids expressing enzymes for L-valine production in E. coli were obtained

Graphical Abstract