William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, 151 West Woodruff Avenue, Columbus, OH 43210, USA.
Bioprocessing Innovative Company, 4734 Bridle Path Ct., Dublin, OH 43017, USA.
Bioresour Technol. 2018 Feb;250:1-9. doi: 10.1016/j.biortech.2017.11.016. Epub 2017 Nov 8.
Propionic acid (PA) is a specialty chemical; its calcium salt is widely used as food preservative. Soy molasses (SM), a low-value byproduct from soybean refinery, contains sucrose and raffinose-family oligosaccharides (RFO), which are difficult to digest for most animals and industrial microorganisms. The feasibility of using SM for PA production by P. acidipropionici, which has genes encoding enzymes necessary for RFO hydrolysis, was studied. With corn steep liquor as the nitrogen source, stable long-term PA production from SM was demonstrated in sequential batch fermentations, achieving PA productivity of >0.8 g/L h and yield of 0.42 g/g sugar at pH 6.5. Economic analysis showed that calcium propionate as the main component (63.5%) in the product could be produced at US $1.55/kg for a 3000-MT plant with a capital investment of US $10.82 million. At $3.0/kg for the product, the process offers attractive 40% return of investment and is promising for commercial application.
丙酸（PA）是一种特殊化学品；其钙盐被广泛用作食品防腐剂。大豆糖蜜（SM）是大豆精炼厂的一种低价值副产物，含有蔗糖和棉子糖家族低聚糖（RFO），大多数动物和工业微生物都难以消化。本研究探索了利用具有 RFO 水解所需酶基因的丙酸短杆菌（P. acidipropionici）从 SM 生产 PA 的可行性。在以玉米浆为氮源的条件下，通过分批补料发酵实现了 SM 稳定、长期的 PA 生产，PA 生产率>0.8 g/L/h，糖得率为 0.42 g/g。经济分析表明，年产 3000 公吨的工厂投资 1082 万美元，产品中主要成分（63.5%）丙酸钙的生产成本为 1.55 美元/公斤。以 3.0 美元/公斤的价格出售产品，该工艺的投资回报率为 40%，具有很大吸引力，有望实现商业化应用。
