Scholarlink

<p>γ-Polyglutamic acid (γ-PGA) is a versatile biopolymer with a wide range of applications. However, its large-scale production remains limited by high costs and low process efficiency. Wheat malt, rich in endogenous amylases and widely used in beer brewing, has seen limited applications in starch hydrolysis for microbial fermentation. This study developed a cost-effective process for γ-PGA production using corn starch liquefied by malt-derived enzymes as the carbon source. Liquefaction was conducted at 65&#xa0;°C and pH 6.5 with a solid-to-liquid ratio of 1:6 and a malt-to-starch ratio of 1:7 for 5&#xa0;h, yielding a solution with a dextrose equivalent (DE) of 21.2% and total sugars of 153&#xa0;mg/mL (4.45&#xa0;mg/mL glucose, 28.09&#xa0;mg/mL maltose, 38.96&#xa0;mg/mL oligosaccharides, and 81.5&#xa0;mg/mL dextrins). Fermentation with <i>Bacillus subtilis</i> SCP010-1 in 250&#xa0;mL shake flasks initially produced 32.5&#xa0;g/L γ-PGA. Optimization of fermentation conditions (72&#xa0;h, 4% inoculum, 50&#xa0;g/L sodium glutamate, and 90&#xa0;g/L liquefied solution) increased the yield to 41.2&#xa0;g/L, closely matching the 41.3&#xa0;g/L predicted by response surface methodology. Scale-up in a 5 L fermenter achieved a maximum yield of 88.2&#xa0;g/L. Economic analysis indicated that using liquefied starch decreased production costs to USD 512, representing reductions of 52.2 and 47.8% compared with sucrose and glucose, respectively. This strategy significantly improves γ-PGA yield and cost efficiency, offering a practical and scalable solution for industrial production.</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

Efficient production of γ-polyglutamic acid from corn starch liquefied with endogenous malt enzymes using Bacillus subtilis SCP010-1

  • 期刊论文

  • 发表日期：

    2025年11月22日

查看全文
  • Ruimin Kong,
  • Hongyan Zhang,
  • Wenshan Cai,
  • Yutao Gou,
  • Wei Li,
  • Yao Ren,
  • Fanglan Ge,
  • Jiao Li

摘要

γ-Polyglutamic acid (γ-PGA) is a versatile biopolymer with a wide range of applications. However, its large-scale production remains limited by high costs and low process efficiency. Wheat malt, rich in endogenous amylases and widely used in beer brewing, has seen limited applications in starch hydrolysis for microbial fermentation. This study developed a cost-effective process for γ-PGA production using corn starch liquefied by malt-derived enzymes as the carbon source. Liquefaction was conducted at 65 °C and pH 6.5 with a solid-to-liquid ratio of 1:6 and a malt-to-starch ratio of 1:7 for 5 h, yielding a solution with a dextrose equivalent (DE) of 21.2% and total sugars of 153 mg/mL (4.45 mg/mL glucose, 28.09 mg/mL maltose, 38.96 mg/mL oligosaccharides, and 81.5 mg/mL dextrins). Fermentation with Bacillus subtilis SCP010-1 in 250 mL shake flasks initially produced 32.5 g/L γ-PGA. Optimization of fermentation conditions (72 h, 4% inoculum, 50 g/L sodium glutamate, and 90 g/L liquefied solution) increased the yield to 41.2 g/L, closely matching the 41.3 g/L predicted by response surface methodology. Scale-up in a 5 L fermenter achieved a maximum yield of 88.2 g/L. Economic analysis indicated that using liquefied starch decreased production costs to USD 512, representing reductions of 52.2 and 47.8% compared with sucrose and glucose, respectively. This strategy significantly improves γ-PGA yield and cost efficiency, offering a practical and scalable solution for industrial production.