The contents were centrifuged (10,000xg for 20 minutes) and the culture supernatant was mixed with three volumes of isopropanol or ethanol slowly along the side wall of the conical flask and allowed to stand at 4oC for 20 minutes for precipitation of exopolysaccharides. The weight of the precipitated EPS was measured after drying at 80o C for three days (Hong et al., 2002).