This is the first report on the characterization and production optimization of poly-N-acetylglucosamine (PNAG) in Staphylococcus saprophyticus A strain producing glucosamine exopolysaccharide was isolated and characterized by biochemical test and 16S rRNA gene sequence homology analysis and named as S saprophyticus BMSZ711 The molecular mass of the purified exopolymer was about 12 kDa. Digestion of the PNAG with Dispersin (R) proved that it has beta-1.6 linkage BMSZ711 can only produce PNAG when grown in M1 minimal medium but not in nutrient rich medium with optimum temperature of 30 degrees C and pH of 7 Glycerol and ammonium sulfate were found to be the best carbon and nitrogen source, respectively Maximum PNAG production was obtained when glycerol 100 mM, ammonium sulfate 0.3%, yeast extract 1.5 g/L, sodium chloride 10 g/L and valine 2 mM were used. (C) 2010 Elsevier Ltd All rights reserved