分批补料高密度发酵生产丙酸杆菌素及其结构分析

Production and Structural Analysis of Propionin by High Cell Density Fed-Batch Fermentation

采用分批补料高密度发酵的方法提高丙酸杆菌素的抑菌活性。从发酵96 h开始,每隔24 h补加2.5 g/L复合碳源(乳酸钠-葡萄糖质量比3∶1)和复合氮源(酵母溶液-玉米酒糟清液体积比1∶30)各100 mL,连续补加5次后,丙酸杆菌素的抑菌活性从17.6 AU/mL提高到31.2 AU/mL。本研究创新性地将玉米酒糟清液作为发酵氮源代替部分酵母溶液,大大降低了丙酸杆菌素的生产成本。另外,通过红外光谱及蛋白酶敏感实验发现丙酸杆菌素是一种具有抑菌活性的蛋白类物质。本研究结果为丙酸杆菌素的工业化生产及其应用提供一定理论支持。

In this work, high cell density fed-batch fermentation was carried out to produce propionin with higher antibacterial activity. Starting from 96 h of fermentation, a mixed carbon source(sodium lactate:glucose = 3:1, m/m) and a mixed nitrogen source(yeast extract:corn distiller’s grains liquid = 1:30, V/V)(100 mL each, 2.5 g/L) were added at 24 h intervals for a total of 120 h. As a result, the antibacterial activity of propionin was increased from 17.6 to 31.2 AU/mL.In this study, we innovatively used corn distiller’s grains liquid as an alternative nitrogen source to partially replace yeast extract in order to greatly reduce the production cost of propionin. In addition, propionin was found to be a proteinaceous material with antibacterial activity as revealed by infrared spectroscopy and protease sensitivity experiments. The results of this study lay the foundation for industrial production and application of propionin.