Exopolysaccharide production and amylase activity of lactic acid bacteria strains

Lactic acid bacteria (LAB) have been widely known as group of exopolysaccharides (EPS) producers which is beneficial for gut health. This study aimed to obtain potential LAB as EPS producers from a laboratory collection of a total of 18 bacterial isolates from human feces. Only seven isolates that observed well grown in sago-starch based medium. The quantification of EPS yield was conducted in two different media and assessed using the phenol-sulfuric acid methods while amylase activity was measured by starch-iodine assay. The yield of EPS was varied from 155.8±7-574.4±4.5 mg/L and from 26.7±4.1-438.8±20 mg/L in glucose and sago starch-based medium, respectively. The amylase activity was ranged from 0.6-2.04 mU/mL. The 16S rRNA analysis showed that those isolates identified as Leuconostoc lactis MC01, Streptococcus equinus MH01 and Enterococcus faecium ME03, E. hirae MB01 and MB02 and E. faecalis ME02 and MK03. E. faecium ME02 and E. faecalis ME03 which showed the highest EPS yield in glucose and sago starch medium, respectively, may be potential for further development as EPS producers while Leuconostoc lactis MC01 which demonstrate the highest amylase activity may be potential as probiotic bacteria because they regarded as generally recognized as safe (GRAS) microorganism.