高产丙酸杆菌的航天诱变叠加化学诱变选育及发酵优化

Screening of High-Producing Propionibacterium via Space Mutagenesis Coupled with Chemical Mutagenesis and Optimization of Its Fermentation Conditions

摘要:

摘要：丙酸是一类重要三碳有机酸，在食品、化工及医药合成等领域具有重要应用价值。微生物发酵产丙酸已成为丙酸合成领域的重要研究方向。该论文研究目的，为获得高产丙酸的詹氏丙酸杆菌，实验以詹氏丙酸杆菌PA2为出发菌株，首先确定了菌株初步发酵丙酸条件，以航天诱变叠加甲基磺酸乙酯化学诱变方法结合高效筛选，获得高产丙酸菌株。研究结果表明，出发菌株PA2经叠加诱变后筛选到高产丙酸突变株DJ04-16丙酸产量达31.78 g·L-1，较出发菌株提升31.27%。通过多次正交实验获得最优丙酸发酵培养基，葡萄糖30 g·L-1、甘油35 g·L-1、蛋白胨9 g·L-1、酵母粉10 g·L-1、硫酸亚铁80 mg·L-1、泛酸钙0.8 mg·L-1、生物素0.8 mg·L-1、160 mg·L-1硫酸镁、2 g·L-1磷酸氢二钾、1 g·L-1磷酸二氢钾以及8 g·L-1玉米浆，DJ04-16菌株于此条件进行发酵，144 h丙酸产量达到33.75g·L-1。结论，航天诱变叠加化学诱变结合高效筛选策略可有效提高詹氏丙酸杆菌产酸能力，所得突变株DJ04-16具有良好的工业应用前景，为微生物法合成丙酸提供了可行性技术支撑。

Abstract:

Abstract：Propionic acid, an important three-carbon organic acid, holds significant application value in food, chemical, and pharmaceutical synthesis industries. Microbial fermentation for propionic acid production has emerged as a crucial research direction in the field of propionic acid biosynthesis. In this study, the wild-type Propionibacterium jensenii strain PA2 was utilized as the progenitor strain. Initial fermentation parameters were established, followed by iterative space mutagenesis and ethyl methanesulfonate (EMS) chemical mutagenesis coupled with high-efficiency screening. It was demonstrated that the iteratively mutagenized strain DJ04-16 achieved propionic acid production of 31.78 g·L?1 under screening conditions, representing a 31.27% increase over PA2. Through orthogonal optimization, the optimal fermentation medium was determined as: glucose (30 g·L?1), glycerol (35 g·L?1), peptone (9 g·L?1), yeast extract (10 g·L?1), FeSO? (80 mg·L?1), calcium pantothenate (0.8 mg·L?1), biotin (0.8 mg·L?1), MgSO? (160 mg·L?1), K?HPO? (2 g·L?1), KH?PO? (1 g·L?1), and corn steep liquor (8 g·L?1). When cultivated in this optimized medium, strain DJ04-16 produced 33.75 g·L?1 propionic acid after 144 h of fermentation. The synergistic combination of space and chemical mutagenesis was demonstrated to significantly improve propionic acid productivity in P. jensenii. The developed mutant DJ04-16 exhibits considerable potential for industrial applications, providing a robust technological platform for microbial propionic acid biosynthesis.