Poly-γ-glutamic acid production from untreated sugarcane molasses by non-sterilized repeated-batch fermentation with Bacillus subtilis GLS-8

作者：Lin Yu, Lin Shu, Huizhen Chen, Xiaoqun Duan, Wei Zeng · 发表于：Chemical Engineering Journal Advances · 年份：2025 · DOI：10.1016/j.ceja.2025.100900 · 被引用次数：1 · 研究领域：Biopolymer Synthesis and Applications、Polyamine Metabolism and Applications、Cancer Research and Treatments

• A γ-PGA producer with untreated sugarcane molasses as carbon source was obtained. • The strain can efficiently produce γ-PGA in the medium with only four components. • The fermentation time for obtaining the maximum γ-PGA titer was only 20-24 hours. • A non-sterilized repeated-batch fermentation with ten cycles was developed. • This study provided a strategy for the efficient and low-cost production of γ-PGA. Poly-γ-glutamic acid (γ-PGA) is a microbial-derived polymer that has wide applications in the fields of medicine, food, cosmetics, agriculture, and environmental protection. Thus, the production of γ-PGA, especially the high-efficiency and low-cost production, has attracted extensive attention. In this study, a strain named Bacillus subtilis GLS-8 capable of using the low-cost sugarcane molasses as the carbon source to produce γ-PGA was obtained through ultraviolet mutagenesis from the parental strain of B. subtilis GXD-20. The γ-PGA with a titer of 33.69 g/L, yield of 1.12 g/g, and productivity of 1.40 g/L/h was obtained from B. subtilis GLS-8 by batch fermentation in a 10 L fermenter based on the optimization of the medium and fermentation process. To further improve the production efficiency, a repeated-batch fermentation with ten cycles was developed in a 10 L fermenter, and the average γ-PGA titer, yield, and productivity reached 32.11 g/L, 1.07 g/g, and 1.61 g/L/h, respectively. To further reduce the production cost, a non-sterilized repeated-batch fermentation w...