The identified isolates were cultivated in exopolysaccharides selection medium (mESM) (van den Berg et al. 1997). A loopful of each of the working cultures was transferred into 100-ml conical flasks containing 10 ml of mESM broth and the broths were incubated anaerobically for 24 hrs at 30oC. 10 ml inocula were transferred into 200-ml conical flasks containing 90 ml of mESM broth and incubated at 30oC for 36 hrs. Samples were taken and analyzed for lactic acid, diacetyl, hydrogen peroxide, pH development, growth and EPS production.