Improvement of the Culture Medium for Latilactobacillus sakei Exhibiting High Lactic Acid Production Isolated Using Response Surface Methodology

Lactic acid is a crucial bio-based chemical with widespread applications in industries such as the food, chemical, bioplastic, and pharmaceutical industries. As demand for lactic acid rises, the search for efficient fermentation strains has become increasingly important. This study aimed to optimize fermentation conditions to enhance lactic acid production using Latilactobacillus sakei L-7. We began by screening key medium components and process parameters through single-factor experiments. Subsequently, we applied response surface methodology for a more comprehensive optimization. The optimal medium formulation was determined to be 40 g/L glucose, 39.54 g/L yeast extract, 10 g/L CH3COONa, 6 g/L K2HPO4, 0.2 g/L MnSO4, 0.4 g/L MgSO4, and 1 mL/L Tween 80. Under the optimized fermentation conditions of 30.27 °C and pH 8.46, the lactic acid production reached 26.18 ± 0.44 g/L, a 50.6% increase compared to pre-optimization levels. These results offered preliminary support for utilizing L. sakei L-7 in the industrial production of lactic acid.