Final pH: 6.8 - 7.0 Final volume: 1000 ml Solution A 980.00 ml Solution B 10.00 ml Solution C 10.00 ml Bring solution A to the boil, then cool to room temperature while sparging with 100% N2 gas. Add solutions B and C, adjust pH to 7.8 with NaOH, and distribute under N2 gas atmosphere into anoxic Hungate-type tubes. During distribution continuously swirl the medium to keep the grey precipitate suspended. Autoclave 15 min at 121°C. Adjust pH of the complete medium to 6.8 - 7.0, if necessary. For DSM 10520: Adjust final pH of autoclaved medium to 7.5 using a sterile anoxic stock solution of Na2CO3 (5% w/v) prepared under 80% N2 and 20% CO2 gas atmosphere. For DSM 15630: Supplement medium after sterilization with 2 g/l Bacto peptone added from a sterile anoxic stock solution. Solution A NaCl 25.00 g K2HPO4 0.50 g NH4Cl 1.00 g Na2SO4 1.00 g CaCl2 x 2 H2O 0.10 g MgSO4 x 7 H2O 2.00 g Na-DL-lactate 2.00 g Yeast extract 1.00 g Sodium resazurin (0.1% w/v) 0.50 ml Distilled water 980.00 ml Solution B FeSO4 x 7 H2O 0.50 g Distilled water 10.00 ml Solution C Na-thioglycolate 0.10 g Ascorbic acid 0.10 g Distilled water 10.00 ml
