Wheat flour based propionic acid fermentation: An economic approach

Abstract: A process for the fermentative production of propionic acid from whole wheat flour using starch and gluten as nutrients is presented. Hydrolysis of wheat flour starch using amylases was optimized. A batch fermentation of hydrolysate supplemented with various nitrogen sources using Propionibacterium acidipropionici NRRL B 3569 was performed. The maximum production of 48.61, 9.40, and 11.06g of propionic acid, acetic acid and succinic acid, respectively, was found with wheat flour hydrolysate equivalent to 90g/l glucose and supplemented with 15g/l yeast extract. Further, replacement of yeast extract with wheat gluten hydrolysate showed utilization of gluten hydrolysate without compromising the yields and also improving the economics of the process. The process so developed could be useful for production of animal feed from whole wheat with in situ production of preservatives, and also suggest utilization of sprouted or germinated wheat for the production of organic acids. [Copyright &y& Elsevier]