Yeast extract 0.20 g 50x Heterotrophic basal salts solution 20.00 ml Ferrous sulfate solution (27.8%) 20.00 ml Distilled water 960.00 ml Dissolve yeast extract in distilled water and add basal salts solution. Adjust to desired pH with H2SO4. Dispense in suitable cultivation vessels and autoclave at 121°C for 20 min. When cool, add filter sterilized ferrous sulfate solution. For DSM 19468: Adjust to pH 2.0. For DSM 19497: Adjust pH of basal medium to 2.0. For DSM 19514: Adjust pH of complete medium to 1.8 - 2.0. For DSM 28176: Reduce amount of ferrous sulfate solution to 5.5 ml, supplement medium after sterilization with 1.0 g/l D-glucose and adjust pH to 2.5. 50x Heterotrophic basal salts solution Na2SO4 x 10 H2O 7.50 g (NH4)2SO4 22.50 g KCl 2.50 g MgSO4 x 7 H2O 25.00 g KH2PO4 2.50 g Ca(NO3)2 x 4 H2O 0.70 g Distilled water 1000.00 ml Ferrous sulfate solution (27.8%) FeSO4 x 7 H2O 278.00 g Distilled water 1000.00 ml Adjust pH to 1.8 with H2SO4; sterilize by filtration.
