Casitone (Difco) 5 g Yeast extract 3 g MgSO4 . 7H2O 2 g Distilled water 1000 ml For solid media add 15 g of agar. Dissolve ingredients and adjust the pH to 7.2. Sterilize at 121°C for 15 min. Add Tween 80 to a final concentration of 1.0% after sterilization.