Extraction and biological activity of exopolysaccharide produced by Leuconostoc mesenteroides SN-8

An exopolysaccharide (EPS)-producing strain SN-8 isolated from Dajiang was identified as Leuconostoc mesenteroides. When sucrose was used as the carbon source for fermentation, the output of EPS was 2.42 g/L High performance liquid chromatography analysis confirmed the presence of monomers such as glucan and mannose. The molecular weight detection value is 2.0 x 10(5) Da. Fourier transform infrared spectroscopy displayed the EPS had the basic skeleton and functional groups of a typical polysaccharide structure. Scanning electron microscopy showed smooth surfaces and compact structure. Thermal performance analysis showed that the highest heat resistance temperature of the EPS was 80 degrees C. Compared with vitamin C, its hydroxyl radical scavenging rate was as high as 32% and 1,1-d ipheny1-2-picrylhydrazyl scavenging rate was as high as 40% under the same concentration. The peanut oil was the most emulsifiable at a concentration of 1.5 mg/mL, and the emulsification index was 0.55. These results might show that the EPS had high application value. (C) 2018 Elsevier B.V. All rights reserved.