Industrial production and functional profiling of probiotic Pediococcus acidilactici 72 N for potential use as a swine feed additive

This study aimed to achieve industrial-scale production of the Thai native swine-derived probiotic strain Pediococcus acidilactici 72 N (P72N) using a cost-effective, food-grade modified medium, and to assess the efficacy of this medium by evaluating the probiotic's functional characteristics and metabolomic profile. Conventional and statistical optimization techniques were used to screen food-grade carbon sources (glucose, dextrose, sucrose) and nitrogen sources (beef extract, yeast extract, sweet whey) to develop the optimal formulation. The final medium contained 10 g/L dextrose, 45 g/L yeast extract, 5 g/L sodium acetate, 2 g/L ammonium citrate, 2 g/L di-potassium hydrogen phosphate, 1 g/L Tween 80, 0.1 g/L magnesium sulfate, and 0.05 g/L manganese sulfate. This formulation achieved significantly higher viable cell counts compared to commercial MRS medium. Scale-up fermentation in 5 L and 50 L fermenters under controlled conditions (37 °C, pH 6.5, 120 rpm) yielded viable cell counts exceeding 9.60 log CFU/mL within 12 h, reducing production costs by 67-86%. P72N in the modified medium demonstrated improved tolerance to environmental stresses. Metabolomic analysis revealed that P72N produced a variety of bioactive metabolites, particularly 1,4-dihydroxy-2-naphthoic acid (1,4-DHNA) and indolelactic acid (ILA) which were detected in higher levels in the modified medium, demonstrating its suitability for industrial production of P72N as a potential feed additive for swine farming.