Evaluation of different nutritional sources in lactic acid bacteria fermentation for sustainable postbiotic production

In recent years, interest in postbiotics has grown due to their potential health benefits and applications in food systems. This study evaluated various nutritional sources for lactic acid bacteria (LAB) fermentation to enhance postbiotic production. Three LAB strains were tested: Pediococcus acidilactici CECT 9879 (PA), Weissella cibaria CECT 30731 (WC), and Lactococcus lactis CECT 30734 (LL). Fermentation experiments assessed bacterial growth, pH levels, and antibacterial activity against E. coli using different carbon and nitrogen sources. Fructose and xylose significantly improved growth in WC (9.39 ± 0.16 log CFU/mL) and LL (9.37 ± 0.22 log CFU/mL) compared to glucose. Ribose enhanced antimicrobial activity in PA (41.67 ± 2.89%) and WC (50.00 ± 0.00%) relative to glucose. Additionally, plant-based nitrogen sources, such as soy (LL: 8.93 ± 0.12 log CFU/mL and 81.67 ± 2.89%) and wheat (WC: 9.40 ± 0.17 log CFU/mL and 65.00 ± 0.00%), along with microbial sources like yeast (PA: 9.57 ± 0.12 log CFU/mL and 40.00 ± 0.00%), effectively supported growth and antibacterial activity. These findings highlight the potential of developing animal-free fermentation media that meet nutritional, safety, and sustainability criteria while making a significant contribution to the optimization of postbiotic production.