Nutrient agar (medium No.1) 1000 ml Yeast extract 4 g Sodium benzoate (or sodium acetate) 2 g Na2HPO4.12H2O 3.6 g KH2PO4 0.98 g MgSO4.7H2O 0.03 g NH4Cl 0.5 g Trace element solution (see medium No.29) 0.2 ml pH 7.0 - 7.2