Exopolysaccharide production by a new Lactobacillus lactis isolated from the fermented milk and its antioxidant properties

Abstract

Exopolysaccharides (EPSs) are synthesized various organisms, including bacteria. These EPSs are used as emulsifying agents in various industries and a search of novel food grade isolate is also a continuous process. In this line of investigation, EPS producing Lactobacillus lactis was used for this study. A potent exopolysaccharide producing Lacobacillus lactis was isolated from milk sources. EPS production was optimized by traditional method initially. Further EPS production was optimized by response surface methodology. Antioxidant properties of the isolated EPS were analyzed. Among various bacterial isolates, L. lactis showed ability to produced maximum amount of exopolysaccharides. Addition of 1% (w/v) maltose enhanced the production of EPS. The nitrogen sources (1%, w/v) such as, ammonium sulphate, casein, skim milk and oat meal stimulated the production of EPS. EPS yield was enhanced for the components of culture medium like gelatine (0.78%), copper sulphate (0.039%) and maltose (0.31%) in optimized medium using Central Composite Design. The isolated EPS showed antioxidant property. Results suggest that EPS and the organism have wide application in food industry.