Propionic acid (PA) is a valuable organic acid for the food and feed industry, but no bioproduction at industrial scale exists so far. As product inhibition is a major burden for bioprocesses producing organic acids, in situ product removal (ISPR) is desirable. Here, we demonstrate a new strategy to produce PA with a co-culture coupled with ISPR using electrodialysis. Specifically, Bacillus coagulans first produces lactic acid (LA) from sugar(s) and LA is converted to PA using Veillonella criceti. Applying ISPR to the mentioned co-culture, the specific PA yield was increased from 0.35 to 0.39 g g-1 compared to no ISPR usage. Furthermore, the productivity was increased from 0.63 to 0.7 g L-1 h-1 by applying ISPR. Additionally, it was shown that co-consumption of xylose and glucose led to a higher PA productivity of 0.73 g L-1 h-1, although PA yield was only increased slightly up to 0.36 g g-1.

中文翻译：

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共培养与集成原位产物去除技术一起生产基于乳酸的丙酸。

丙酸（PA）是食品和饲料工业中有价值的有机酸，但是到目前为止，还没有工业规模的生物生产。由于产物抑制是产生有机酸的生物过程的主要负担，因此原位产物去除（ISPR）是理想的。在这里，我们展示了一种通过电渗析结合ISPR与共培养物生产PA的新策略。具体而言，凝结芽孢杆菌首先从一种或多种糖中产生乳酸（LA），然后使用Veillonella criceti将LA转化为PA。将ISPR应用于上述共培养物，与不使用ISPR相比，单位PA的产量从0.35 g g-1增加到0.39 g g-1。此外，通过使用ISPR，生产率从0.63 L-1 h-1增加到0.7 g L-1 h-1。此外，还表明，木糖和葡萄糖的共同消耗可导致更高的PA生产率0.73 g L-1 h-1，