Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology, Denickestr.15, 21073 Hamburg, Germany.
Appl Microbiol Biotechnol. 2013 Jul;97(13):5771-7. doi: 10.1007/s00253-013-4913-y. Epub 2013 May 1.
Propionic acid is presently mainly produced by chemical synthesis. For many applications, especially in feed and food industries, a fermentative production of propionic acid from cheap and renewable resources is of large interest. In this work, we investigated the use of a co-culture to convert household flour to propionic acid. Batch and fed-batch fermentations of hydrolyzed flour and a process of simultaneous saccharification and fermentation were examined and compared. Fed-batch culture with substrate limitation was found to be the most efficient process, reaching a propionic acid concentration of 30 g/L and a productivity of 0.33 g/L*h. This is the highest productivity so far achieved with free cells on media containing flour hydrolysate or glucose as carbon source. Batch culture and culture with controlled saccharification and fermentation delivered significantly lower propionic acid production (17-20 g/L) due to inhibition by the intermediate product lactate. It is concluded that co-culture fermentation of flour hydrolysate can be considered as an appealing bioprocess for the production of propionic acid.
丙酸目前主要通过化学合成生产。对于许多应用，特别是在饲料和食品工业中，利用廉价可再生资源通过发酵生产丙酸具有很大的意义。在这项工作中，我们研究了利用共培养物将家用面粉转化为丙酸。考察了水解面粉的分批和补料分批发酵以及同步糖化和发酵过程，并对其进行了比较。发现底物限制的补料分批培养是最有效的工艺，达到 30 g/L 的丙酸浓度和 0.33 g/L*h 的生产率。这是迄今为止在含有面粉水解物或葡萄糖作为碳源的培养基上用游离细胞实现的最高生产率。由于中间产物乳酸的抑制作用，分批培养和控制糖化和发酵的培养导致丙酸产量显著降低（17-20 g/L）。结论是，面粉水解物的共培养发酵可以被认为是生产丙酸的一种有吸引力的生物过程。
