Screening of significant media components for propionic acid production by P. freudenreichii

In this study, the capability of propionic acid (PA) production by Propionibacterium freudenreichii over waste frying sunflower oil as a renewable carbon source was studied. Two optimization steps were applied. At the first step, the amount of frying oil in the media was optimized using one factor at a time method. The amount of 4% w/v oil was shown to be the best for PA production. In order to improve the acid production, the Plackett-Burman experimental design was applied to evaluate the significant parameters that have large effect on the fermentation and with this experimental design a successful results were obtained. Seven components consisted of DMB, CoCl2.6H2O, Na2MoO4.2H2O, H3BO3, EDTA and Fe2SO4.7H2O were investigated. It was found that only H3BO3, Na2MoO4 and EDTA were among the significant nutrients