(697f) Production of Propionic Acid from Soy Molasses By High-Cell Density Fermentation with Propionibacterium Acidipropionici

The three-carbon fatty acid propionic acid has wide industrial applications such as food and feed preservatives, perfumes and artificial flavorings. Its current industrial production is mainly through petrochemical processes, which are not sustainable and result in environmental concerns. In contrast, propionic acid production through fermentation is sustainable and can fulfill consumer demands for natural product. Although the best propionic acid producer Propionibacterium acidipropionici can produce propionic acid with high yield, purity and productivity, further production cost reduction is required to make fermentation process economically competitive against petrochemical process. In this study, low-cost soy molasses, a byproduct from soybean refinery, was used as the sole carbon source to produce propionic acid by P. acidipropionici in batch and fed-batch fermentations. After simple pretreatments to remove undesirable inhibitors, soy molasses, which contained sucrose, stachyose, raffinose, glucose, xylose, galactose, fructose and lactic acid, could be readily fermented by P. acidipropionicito produce propionic acid at a yield of >0.4 g/g sugar consumed, confirming that soy molasses is a promising feedstock for economical production of propionic acid.