Comparative influence of medium composition on biomass growth, lactic acid and Exopolysaccharides Production by some Strains of Lactic Acid Bacteria

Abstract

To promote the overall quality of fermented dairy products (FDP) which depends on the types and characteristics of the starter organisms used in the production, the effect of medium composition on biomass growth, viscosity, exopolysaccharide and lactic acid production by EPSproducing lactic acid bacteria isolates was investigated. Medium composition had profound effect on the studied parameters. Among the five medium used for the cultivation of the isolates, maximum biomass growth and viscosity production was achieved in partially de-protenised whey medium (PDW) in which Lactococcus piscium (OLHF6) and Lactobacillus plantarum (LPN1) exhibit the highest biomass growth and viscosity with concentration of 1.58 and 1.561mPa.S. Lactobacillus plantarum (LPN1) (1.58mPa.S), L.casei (LCN1) (1.475 mPa.S), L.plantarum (LPN3) (1.48mPa.S), L.plantarum (LPY80 (1.48mPa.S) and Lactococcus piscium (OLHF6) (1.185mPa.S) was found to be a good starter for development of viscous medium in the respective media. Whey was the best medium for EPS production in which L. casei (LCN1)) was the best starter (198.69mg/l). Sweet whey medium, modified MRS medium, Whey and partially deproteinised whey medium was not favourable for lactic acid production by the isolates but Semidefine medium was the best for lactic acid development in which L.plantarum (LPW10) was found to be the best starter for lactic acid development (5.57g/l).