Lactiplantibacillus plantarum D25: A Promising Probiotic with Multi-Target Antibacterial Efficacy, Unique Metabolic Traits, Dual Thermal Sensitivity, and Biopreservative Potential for Refrigerated Shrimp

The improper use of chemical preservatives poses significant food safety risks, highlighting the urgent need for safer and more sustainable preservation methods. In this study, we systematically evaluated antibacterial efficacy, probiotic properties, and biosafety of a novel Lactiplantibacillus plantarum D25 strain (3.29 Mb) through comprehensive phenotypic and genotypic analyses. The cell-free supernatant (CFS) of L. plantarum D25 (CFS-LpD25) demonstrated broad-spectrum antimicrobial activity, with particularly strong inhibition on Vibrio cholerae, yielding an inhibition zone diameter of 20.96 mm. The potent antibacterial effects were primarily attributed to the low pH (3.83) and high levels of organic acids such as lactic acid (12.49 mg/mL). Application of 10% CFS-LpD25 significantly prolonged the refrigerated shelf life of Pacific white shrimp (Litopenaeus vannamei) meat, surpassing the effectiveness of the chemical preservative potassium sorbate. This treatment also effectively mitigated sensory deterioration, stabilized pH, and reduced lipid oxidation and protein degradation. L. plantarum D25 exhibited tolerance to gastrointestinal and food processing stresses, thriving at pH 3.5, under osmotic pressure (≤4% NaCl), and in bile salts (<20 mM). Its dual thermal sensitivity (50–55 °C) enhanced its suitability for industrial applications, with unique metabolic traits. Biosafety assessments confirmed the absence of hemolytic and gelatinase activities. Overall, these findings establish L. plantarum D25 as a potential probiotic candidate and natural biopreservative in functional foods with antibacterial activity, supporting the reduction in chemical preservatives in the food industry.