Effect of Sodium Acetate and Trace Element (Se2+, Zn2+) on Exopolysaccharide Production by Lactobacillus plantarum and Promote Antioxidant Capacity

Abstract

L. plantarum producing EPS plays an important role as an antioxidant, anti-proliferative, and anticancer. This study aims to increase the production of EPS by L. plantarum through modification of MRS (de Mann Rogosa Sharpe) media mixed with coconut water, treated with natrium acetate, Se, and Zn at different concentration, as well as understanding its effect on antioxidant activity. The effect of adding sodium acetate with different concentrations of 0.25, 0.50, 0.75, and 1.0% into mixed media MRS coconut water, (1:3) was studied. Fermentation experiments at different of Se2+ concentration (mM): 50; 75; 100; 125; 150; and 175, and addition of variation Zn2+ concentration (mM): 2.5; 5.0; 7.5; 10.0; 12.5; and 15.0), were carried out separately. Antioxidant potential was tested by FRAP (ferric reducing antioxidant power) and ABTS (2.2′-azinobis (3-ethyl benzatiazoline)-6-sulfonate). The results showed that the addition of sodium acetate with different concentrations showed a significant difference to the dry weight of EPS (P < 0.05). The increase in sodium acetate concentration was up to 1%, in line with the increase in EPS production by L. plantarum (g/g DW biomass). The addition of Se2+ 100 mM increased the ratio of glucose to protein content by 2.121. The value of the antioxidant activity of Fe (II) was 311.54, and the ABTS test obtained IC50 of 83.041. A separate experiment with the addition of Zn2+ in the fermentation medium of L. plantarum produced a fluctuating exopolysaccharide. The value of the antioxidant activity of Fe (II) M using the FRAP method was 275.886. The IC50 value with the ABTS method is 73.2942. Characterization of EPS from L. plantarum using FTIR (Fourier transforms infrared spectrophotometry) has hydroxyl, carboxylate, and aromatic functional groups.