Introduction
Propionic acid is widely used as an antifungal in food
[1], feed [2] and as an intermediate in the synthesis of herbicides,
cellulose acetate – propionate plastics, solvents and
pharmaceuticals [3, 4]. Chemical synthesis from petroleum
feedstock is currently the main source of propionic acid.
Fermentation processes utilizing low-value industrial byproducts
as carbon sources may become an attractive alternative
[5].