| Sodium acetate | 0.5 | g | | Sodium propionate | 0.5 | g | | Sodium succinate | 0.5 | g | | Sodium malate | 0.5 | g | | NH4Cl | 0.4 | g | | K2HPO4 | 1 | g | | MgSO4·7H2O | 0.2 | g | | CaCl2·2H2O | 0.05 | g | | FeCl3·6H2O | 0.005 | g | | NaCl | 0.1 | g | | Yeast extract | 0.1 | g | | Biotin | 0.01 | mg | | Thiamine-HCl | 0.2 | mg | | Agar (if needed) | 20 | g | | Distilled water | 1 | L | | pH 6.8 | | | | | Mix ingredients except for biotin and thiamine-HCl solutions, and adjust pH to 6.8 with pH-adjusting agent. Dispense the medium into suitable culture vessels under a stream of nitrogen gas, seal with butyl rubber stoppers, and autoclave at 121°C for 15 min. Prior to inoculation, aseptically and anaerobically add the sterile-filtrated biotin and thiamine-HCl solutions and neutralized sulfide solution*. Sterile syringes are used to inoculate and remove samples. | | | | | | | | | | *Neutralized sulfide solution | | | | Na2S·9H2O | 1.5 | g | | | | Distilled water | 100 | ml | | | | The sulfide solution is prepared in a vessel sealed with a butyl rubber stopper. Autoclave at 121℃ for 15 min under a N2 atmosphere. After cooling to room temperature, the pH is adjusted to about 7.3 by adding of sterile 2 N H2SO4 drop-wise with a syringe without opening the bottle. Appearance of yellow colour indicates the pH is about 8. The vessel should be shaken continuously to avoid precipitation of elemental sulfur. The final solution should be transparent yellow. |
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