Characterization and Biological Activity of a Novel Exopolysaccharide Produced By Pediococcus Pentosaceus SSC-12 From Silage
Abstract Background: The exopolysaccharides (EPS) produced by lactic acid bacteria (LAB) are widely used in various fields because of their safety and various biological activities. In this study, we extracted and characterized the composition as well as antioxidant and antibacterial activities of EPS from Pediococcus pentosaceus SSC-12 isolated from the silage.Results: The LAB strain SSC-12 was screened and identified as Pediococcus pentosaceus, based upon 16S rDNA gene sequencing and Neighbor Joining (NJ) phylogenetic analysis. The analysis of the EPS production kinetics results of SSC-12 showed that the EPS production reached the maximum at 20 h of culture. High-performance anion exchange chromatography (HPAEC) analysis showed that the EPS produced by SSC-12 was a heteropolysaccharide comprising glucose (42.6 %), mannose (28.9 %), galactose (16.2 %), arabinose (9.4 %) and rhamnose (2.9 %). The EPS had good antioxidant activity, especially hydroxyl radical scavenging activity. When the concentration of the EPS produced by SSC-12 (SSC-12 EPS) was 10 mg/mL, its 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging ability, hydroxyl radical scavenging ability, superoxide scavenging ability, and reduction ability were 77.4 %, 97.5 %, 77.5 % and 1.3, respectively. At 10 mg/mL,SSC-12 EPS completely killed Staphylococcus aureus GDMCC 1.1220 and substantially inhibited the growth of Salmonella enterica subsp. enterica GDMCC 1.345; however, it had a weak inhibitory effect on Listeria monocytogenes GDMCC 1.347. Conclusions: Due to its strong antioxidant and antibacterial properties, EPS produced by LAB strain SSC-12 have potential application as a bioactive product in the feed, food, and pharmaceutical industries.