Scholarlink

<p>The integration of traditional strain cultivation with metabolic engineering has enabled the development and successful commercialization of high-yield riboflavin-producing <i>Bacillus subtilis</i> strains. Nevertheless, the mechanism through which dissolved oxygen regulates riboflavin yield in industrial fermentation remains poorly understood. In this study, transcriptome data mining identified a novel transcription factor, YgzD, whose expression is regulated by low-oxygen conditions. RT-qPCR and fusion reporter gene assays confirmed that YgzD expression is activated under low dissolved oxygen. Under low dissolved oxygen conditions, YgzD deficiency significantly upregulates the transcription level of <i>purR</i>, which encodes a repressor of purine metabolism. This indicates that YgzD functions to promote <i>purR</i> expression. Consequently, by modulating <i>purR</i> transcription level, YgzD indirectly regulates the synthesis of GTP, a key precursor for riboflavin biosynthesis. Concurrently, YgzD acts as a negative regulator of <i>alsS</i>, a key gene in central carbon metabolism. Based on these findings, a 5′UTR engineering approach was employed to fine-tune YgzD expression, leading to the identification of optimal 5′UTR-ygzD combinations. The final engineered strain, constructed by integrating a synthetic <i>Srib</i> operon, achieved a riboflavin titer of 11.49&#xa0;g/L in a 5 L fermenter, representing a 50.39% increase in yield. Elucidating the environmental response mechanisms in engineered strains provides a critical foundation for systematically enhancing their production performance.</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

Enhancing riboflavin yield by elucidating the regulatory role of transcription factor YgzD in Bacillus subtilis

  • 期刊论文

  • 发表日期：

    2026年1月2日

查看全文
  • Jiajia You,
  • Kang Wang,
  • Xiaoling Zhang,
  • Yuxuan Du,
  • Minglong Shao,
  • Yanan Li,
  • Taowei Yang,
  • Xuewei Pan,
  • Xian Zhang,
  • Zhiming Rao

摘要

The integration of traditional strain cultivation with metabolic engineering has enabled the development and successful commercialization of high-yield riboflavin-producing Bacillus subtilis strains. Nevertheless, the mechanism through which dissolved oxygen regulates riboflavin yield in industrial fermentation remains poorly understood. In this study, transcriptome data mining identified a novel transcription factor, YgzD, whose expression is regulated by low-oxygen conditions. RT-qPCR and fusion reporter gene assays confirmed that YgzD expression is activated under low dissolved oxygen. Under low dissolved oxygen conditions, YgzD deficiency significantly upregulates the transcription level of purR, which encodes a repressor of purine metabolism. This indicates that YgzD functions to promote purR expression. Consequently, by modulating purR transcription level, YgzD indirectly regulates the synthesis of GTP, a key precursor for riboflavin biosynthesis. Concurrently, YgzD acts as a negative regulator of alsS, a key gene in central carbon metabolism. Based on these findings, a 5′UTR engineering approach was employed to fine-tune YgzD expression, leading to the identification of optimal 5′UTR-ygzD combinations. The final engineered strain, constructed by integrating a synthetic Srib operon, achieved a riboflavin titer of 11.49 g/L in a 5 L fermenter, representing a 50.39% increase in yield. Elucidating the environmental response mechanisms in engineered strains provides a critical foundation for systematically enhancing their production performance.