Abstract: Phthalate esters (PAEs), widely used as plasticizers in plastic products, exhibit environmental persistence and health risks through their metabolic intermediate, monobutyl phthalate (MBP). Microbial adsorption represents an effective approach for removing such contaminants. In this study, five strains able to efficiently adsorb MBP were selected from 28 exopolysaccharide (EPS)-producing strains of lactic acid bacteria. These five strains not only exhibited broad-spectrum adsorption capabilities toward MBP and typical PAEs, but also demonstrated enhanced adsorption performance in a simulated gastric fluid environment. However, significant divergence was observed among the strains in a simulated intestinal fluid: Lactiplantibacillus plantarum strains (R66, RS20D, DL7X) displayed stronger gastrointestinal adaptability, maintaining over 20% MBP adsorption after continuous digestive treatment; their performance was significantly superior to that of Limosilactobacillus fermentum. Among these L. plantarum strains, L. plantarum RS20D was selected as it had the highest EPS-producing capacity. RS20D rapidly adsorbed dibutyl phthalate (DBP), reaching equilibrium within 15 minutes. Its heat-inactivated cells achieved the highest adsorption efficiency of 72.92%. Moreover, RS20D grew rapidly, possessed strong acid-producing capacity, and exhibited adaptability to a wide range of temperature, pH, and osmotic pressure, along with favorable tolerance to simulated gastrointestinal conditions. Furthermore, the strain demonstrated both antimicrobial activity and intrinsic antibiotic resistance, suggesting a promising probiotic potential alongside its environmental remediation capabilities.

Key words: phthalate esters; dibutyl phthalate; Lactiplantibacillus plantarum; adsorption; probiotic properties