The microbial production of valuable chemical feedstocks from renewable carbon sources has received increased attention by science and industry. The objective of this work was to study the biosynthesis of propionic acid (PA) by a mixed culture of Propionibacterium freundenreichii ATCC 6207 and Lactobacillus paracasei subsp. paracasei from whey cheese. The effects of L. paracasei inoculum, lactose and calcium carbonate (CaCO₃) concentrations on propionic acid (PA) production by P. freundenreichii were investigated following a central composite rotational design with 18 treatments, using whey as source of carbon and nitrogen. Fermentation assays were carried out in Erlenmeyer flasks incubated at 30 °C without shaking during 120 h and for each treatment a kinetic study was done. A production of 23 g L⁻¹ of propionic acid was obtained. Concentrations of lactose below 40 g L⁻¹ and above 30 g L⁻¹ of CaCO₃ promoted higher PA production, productivity and yield and acetic acid production. This mixed culture can efficiently use whey for PA biosynthesis, reducing environmental damage from traditional synthesis.

从可再生碳源微生物生产有价值的化学原料已受到科学和工业界越来越多的关注。这项工作的目的是通过弗氏丙酸杆菌ATCC 6207 和副干酪乳杆菌 亚种的混合培养物研究丙酸(PA) 的生物合成。 来自乳清奶酪的副干酪。的影响副干酪乳杆菌接种物，乳糖和碳酸钙，碳酸钙（CaCO ₃通过）上丙酸浓度（PA）生产P. freundenreichii使用乳清作为碳源和氮源，按照中心复合旋转设计进行了 18 次处理进行了研究。发酵测定在 30 °C 下孵育 120 小时的锥形瓶中进行，每次处理都进行动力学研究。获得23g L ^-1丙酸的产量。乳糖浓度低于 40 g L ^-1和高于 30 g L ^-1的 CaCO ₃促进了更高的 PA 产量、生产力和产率以及乙酸产量。这种混合培养可以有效地将乳清用于 PA 生物合成，减少传统合成对环境的破坏。