• Yeast extract 0.30 g
• Ethanol 0.50 ml
• Na-pyruvate 1.00 g
• (NH₄)-acetate 0.50 g
• Fe III citrate solution (0.1% w/v in water) 5.00 ml
• KH₂PO₄ 0.50 g
• MgSO₄·7H₂O 0.40 g
• NaCl 0.40 g
• NH₄Cl 0.40 g
• CaCl₂·2H₂O 0.05 g
• B₁₂ vitamin solution (10 mg in 100 ml of water) 1 ml
• Trace elements solution SL-6 (see medium 196) 1.00 ml
• Distilled water up to 1 L

Adjust pH to 6.8 Distribute the medium in 12-15 ml tubes with screw cap. Fill the tubes up to 1 cm from the top. Autoclave them at 121°C for 20 min with the cap slightly open. Fill the tubes completely, add 0.01 ml of 0.50% sterile cysteine and close inmediatly after autoclaving.