Scholarlink

Abstract <p>Poly-γ-glutamic acid (γ-PGA) has diverse applications from cosmetic to drug delivery. The production of γ-PGA primarily relies on microbial fermentation using <i>Bacillus</i> spp. supplemented with <span>l</span>-glutamate supplementation. However, the high cost of <span>l</span>-glutamate supplementation limits industrial production. This study aimed to achieve direct γ-PGA production from glucose using a <i>Corynebacterium glutamicum-Bacillus</i><i> licheniformis</i> coculture system. To create such a coculture system, we utilized <i>B. licheniformis</i> ATCC 9945a, a natural <span>l</span>-glutamate-dependent γ-PGA producing strain, and <i>C. glutamicum</i> F343, which exhibited an excellent capacity to produce <span>l</span>-glutamate from glucose. <i>B. licheniformis</i> ATCC 9945a grew well and produced small amounts of γ-PGA in the medium of <i>C. glutamicum</i> F343. Subsequently, <i>B. licheniformis</i> ATCC 9945a was cultured using the supernatant collected from the <i>C. glutamicum</i> F343 fermentation broth to investigate its effect on the fermentation profile. It was found that <i>B. licheniformis</i> ATCC 9945a produced more γ-PGA in the supernatant compared to when exogenously supplemented with <span>l</span>-glutamate. Moreover<b>,</b> nine intracellular metabolites were discovered to be strongly connected to γ-PGA synthesis by UPLC-MS. Finally, the coculture of <i>C. glutamicum</i> F343 and <i>B. licheniformis</i> ATCC 9945a to produce γ-PGA was conducted. We successfully achieved direct γ-PGA production from glucose under optimal conditions, including an inoculation time of 4 h for <i>B. licheniformis</i> after <i>C. glutamicum</i> inoculation, a 75% inoculum ratio of <i>C. glutamicum</i>, and a total inoculum size of 10% culture volume. The coculture system produced 12.49&#xa0;g/L of γ-PGA in a shake flask and 22.7&#xa0;g/L in a 5-L fermentor.</p> Key points <p>• <i>C. glutamicum F343 could produce L-glutamate from glucose as a precursor for&#xa0;PGA synthesis by B. licheniformis ATCC 9945a</i>.</p> <p>• <i>The C. glutamicum-B. licheniformis coculture system could produce γ-PGA up to&#xa0;22.7 g/L</i>.</p> <p>• <i>Nine intracellular metabolites demonstrated a remarkable influence on γ-PGA&#xa0;synesis by UPLC-MS and metabolite profiling</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

Coculture Corynebacterium glutamicum and Bacillus licheniformis for producing poly-γ-glutamic acid from glucose

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2025年12月9日

查看全文
  • Wanjing Liu,
  • Jiyue Wang,
  • Luning Gu,
  • Haozhe Zhou,
  • Hui Cheng,
  • Jian Zha,
  • Dejing Yin,
  • Jianying Qian,
  • Pu Zheng,
  • Xiaomei Zhang,
  • Mattheos A. G. Koffas,
  • Guoqiang Xu,
  • Jinsong Shi,
  • Zhenghong Xu

摘要

Abstract

Poly-γ-glutamic acid (γ-PGA) has diverse applications from cosmetic to drug delivery. The production of γ-PGA primarily relies on microbial fermentation using Bacillus spp. supplemented with l-glutamate supplementation. However, the high cost of l-glutamate supplementation limits industrial production. This study aimed to achieve direct γ-PGA production from glucose using a Corynebacterium glutamicum-Bacillus licheniformis coculture system. To create such a coculture system, we utilized B. licheniformis ATCC 9945a, a natural l-glutamate-dependent γ-PGA producing strain, and C. glutamicum F343, which exhibited an excellent capacity to produce l-glutamate from glucose. B. licheniformis ATCC 9945a grew well and produced small amounts of γ-PGA in the medium of C. glutamicum F343. Subsequently, B. licheniformis ATCC 9945a was cultured using the supernatant collected from the C. glutamicum F343 fermentation broth to investigate its effect on the fermentation profile. It was found that B. licheniformis ATCC 9945a produced more γ-PGA in the supernatant compared to when exogenously supplemented with l-glutamate. Moreover, nine intracellular metabolites were discovered to be strongly connected to γ-PGA synthesis by UPLC-MS. Finally, the coculture of C. glutamicum F343 and B. licheniformis ATCC 9945a to produce γ-PGA was conducted. We successfully achieved direct γ-PGA production from glucose under optimal conditions, including an inoculation time of 4 h for B. licheniformis after C. glutamicum inoculation, a 75% inoculum ratio of C. glutamicum, and a total inoculum size of 10% culture volume. The coculture system produced 12.49 g/L of γ-PGA in a shake flask and 22.7 g/L in a 5-L fermentor.

Key points

• C. glutamicum F343 could produce L-glutamate from glucose as a precursor for PGA synthesis by B. licheniformis ATCC 9945a.

• The C. glutamicum-B. licheniformis coculture system could produce γ-PGA up to 22.7 g/L.

• Nine intracellular metabolites demonstrated a remarkable influence on γ-PGA synesis by UPLC-MS and metabolite profiling.