Cellular antioxidant properties of nontoxic exopolysaccharide extracted from Lactobacillales (Weissella cibaria) isolated from Korean kimchi

The present work isolated and identified five lactic acid bacteria (LAB) from Korean kimchi and then evaluated their exopolysaccharide (EPS) production efficiency. SY003 (Weissella cibaria) produced a high level of EPS when compared to the other isolates. Therefore, EPS from SY003 was selected for purification and characterization using column chromatography, HPLC, FTIR, and NMR. The HPLC analysis indicated that EPS was composed of glucose (38.95%) and galactose (61.04%). FTIR and NMR results confirmed that monosaccharides of EPS were linked through α-D-Glc-(1 → and →6)-β-D-Gal-(1→ linkage. SEM results displayed the nonporous and smooth surface of EPS. In the antioxidant assay, EPS (1 mg/mL) scavenged 34% of DPPH and 90% of ABTS+. Additionally, toxicological experiments (CAM assay, hemolysis assay, and cytotoxicity) established that EPS was nontoxic and biocompatible for biomedical applications. EPS (1 mg/mL) protected HEK293 cells from H2O2 induced oxidative stress shown by cellular antioxidant assay. The present work concluded that EPS produced from W. cibaria (SY003) isolated from Korean kimchi was biocompatible and merited consideration for the development of antioxidant agents. [Display omitted] •EPS producing LAB (W. cibaria) isolated from Korean kimchi identified by 16S rRNA seq.•EPS was purified and structurally characterized by FTIR, HPLC, and NMR•EPS consisted of the trace of phenol, flavonoids, glucose (38.95%), and galactose (61.04%)•Toxicological studies revealed that EPS was nontoxic and biocompatible•EPS exhibited promising free radicals scavenging and cellular antioxidant activities.