Antioxidant and Antimicrobial Activities of Exopolysaccharides from Yoghurt Starter

The in vitro antimicrobial and antioxidant activities of the exopolysaccharide (EPS) extracted from yoghurt starter were investigated. Antimicrobial activity tests were carried out using disc diffusion methods with Escherichia coli, Staphylococcus aureus and Streptococcus D, Proteus spp and the yeast of Candida albicans. The antioxidant properties were evaluated using the test of DPPH free radical trapping. The results show that the EPS has weak antimicrobial activity against the tested strains with inhibitions zones ranging from 9 to 13 mm. EPS could reduce the free radical (DPPH) to diphenylpicrylhydrazine a yellow-colored at 24.25% showing antioxidant activity less than that of ascorbic acid which was 69.79%.