What is SAB medium?

Answer 1

A Versatile Medium for Cultivating Methanogenic Archaea

• Saber Khelaifia,
• Didier Raoult,
• Michel Drancour

SAB medium contains the following: NiCl2. 6H2O, 1.5 mg/L; FeSO4. H2O, 0.5 mg/L; MgSO4. 7H2O, 0.8 g/L; KH2PO4, 0.5 g/L; K2HPO4, 0.5 g/L; KCl, 0.05 g/L; CaCl2. 7H2O, 0.05 g/L; NaCl, 1.5 g/L; NH4Cl, 1 g/L; MnSO4. 7H2O, 0.6 mg/L; ZnSO4. 7H2O, 0.1 mg/L; CuSO4.5H2O, 0.02 mg/L; KAl(SO4)2. 12H2O, 0.2 µg/L; H3BO3, 7 µg/L; CoSO4. 7H2O, 4 µg/L; Na2MoO4. 2H2O, 0.5 mg/L; Na2SeO3.5H2O, 3 µg/L; Na2WO4 × 2H2O, 4 µg/L; Nitrilotriacetic acid, 0.15 mg/L; sodium acetate, 1 g/L; trypticase, 2 g/L; yeast extract, 2 g/L; L-cysteine hydrochloride monohydrate, 0.5 g/L; valeric acid, 5 mM; isovaleric acid, 5 mM; 2-methylbutyric acid, 5 mM; isobutyric acid, 6 mM; 2-methyl valeric acid, 5 mM; resazurin, 1 mg/L. The medium was boiled under a nitrogen flux. Bottles were then closed using a lid of aluminum foil and then cooled off to room temperature under N2 or 80% N2/20%CO2 flushing until the medium became transparent. The following compounds were prepared and autoclaved anaerobically under N2and aseptically added to the medium to a final concentration of 2% (v/v): NaHCO3, 10%; Na2S, 2%; methanol, 4 M; sodium format, 8 M; and vitamin solution [32]. All of the solutions were prepared in anaerobic water, with N2/CO2 flushing to replace the oxygen [9], [33]. pH was adjusted to 7.5 with 10 M KOH. The culture was incubated using a gas mixture of 80% H2+20% CO2 at 2.5-bar pressure required for the growth of methanogenic archaea [10], [14]. For all the methanogenic archaea strains, the culture was performed in Hungate tubes incubated at 37°C with agitation.