Characterization, bioactivities, and rheological properties of exopolysaccharide produced by novel probiotic Lactobacillus plantarum C70 isolated from camel milk.

Various industries highly regard the functionalities and bioactivities of bacterial polysaccharides. We aimed to characterize the exopolysaccharide (EPS) produced by novel probiotic Lactobacillus plantarum C70 (accession number KX881779) isolated from camel milk and to investigate its bioactivities and rheological properties. EPS-C70 had a weight-average molecular weight (Mw) of 3.8 × 10⁵ Da. Arabinose (13.3%), mannose (7.1%), glucose (74.6%), and galactose (5.0%) were the major monosaccharides constituents. EPS-C70 had two endothermic peaks at 76.95°C and 158.76°C corresponding to glass transition (T_g) and melting point (T_m), respectively. Zeta potential and particle size of EPS-C70 were -330.71 mV and 525.5 nm, respectively. DPPH and ABTS of EPS-C70 were 75.91% and 49.42% at 10 mg/mL concentration, respectively. The cytotoxic activities against colon cancer and breast cancer lines were 88.1% and 73.1% at concentration 10 mg/mL, respectively. EPS-C70 exhibited shear-thinning behaviour. Salts and pH values had a significant impact on the rheological properties of EPS-C70.