Ren College of life Sciences, Sichuan Normal University, Chengdu, 610101, Sichuan, China.
World J Microbiol Biotechnol. 2024 Oct 3;40(11):338. doi: 10.1007/s11274-024-04141-5.
Starch, a crucial raw material, has been extensively investigated for biotechnological applications. However, its application in γ-polyglutamic acid (γ-PGA) production remains unexplored. Based on γ-PGA output of Bacillus subtilis SCP010-1, a novel asynchronous saccharification and fermentation process for γ-PGA synthesis was implemented. The results revealed that a starch concentration of 20%, α-amylase dosage of 75 U/g, liquefaction temperature of 72℃, and γ-PGA yield of 36.31 g/L was achieved. At a glucoamylase dosage of 100 U/g, saccharification 38 h at 60℃, the yield of γ-PGA increased to 48.88 g/L. The contents of total sugar, glucose, maltose and oligosaccharide in saccharified liquid were determined. Through batch fermentation of saccharified liquid in fermentor, the γ-PGA output was elevated to 116.08 g/L. This study can offer a potential cost reduction of 40%, which can be a promising advancement in industrial γ-PGA production. Moreover, our approach can be applied in other starch-based fermentation industries.
淀粉作为一种重要的原材料，已被广泛研究用于生物技术应用。然而，其在γ-聚谷氨酸（γ-PGA）生产中的应用仍未得到探索。基于枯草芽孢杆菌 SCP010-1 产生的γ-PGA 产量，我们实施了一种新型的γ-PGA 合成异步糖化发酵工艺。结果表明，淀粉浓度为 20%、α-淀粉酶用量为 75 U/g、液化温度为 72℃时，γ-PGA 的产率达到 36.31 g/L。当葡萄糖淀粉酶用量为 100 U/g、60℃糖化 38 h 时，γ-PGA 的产率增加到 48.88 g/L。对糖化液中的总糖、葡萄糖、麦芽糖和寡糖含量进行了测定。通过发酵罐中糖化液的分批发酵，γ-PGA 的产量提高到 116.08 g/L。本研究可降低 40%的成本，有望推动工业γ-PGA 生产的发展。此外，我们的方法可以应用于其他基于淀粉的发酵工业。
