# 883: CALDIVIRGA MEDIUM ## Main sol. 883 2.94 g Trisodium citrate x 2 H2O 1.3 g (NH4)2SO4 0.28 g KH2PO4 0.25 g MgSO4 x 7 H2O 0.07 g CaCl2 x 2 H2O 0.02 g FeCl3 x 6 H2O 10 ml **Allen's trace element solution** 0.5 ml Sodium resazurin (0.1% w/v) 10 g Sulfur (powdered) 0.5 g Yeast extract (OXOID) 1 ml **Wolin's vitamin solution (10x)** 0.5 g Na2S x 9 H2O 1000 ml Distilled water 1. Dissolve ingredients except sulfur, yeast extract, vitamins and sulfide, then adjust the pH to 3.5 with 4 N H2SO4. Sparge medium with 100% N2 gas for 30 - 45 min to make it anoxic, then dispense under same gas atmosphere into anoxic Hungate-type tubes or serum vials which contain already the appropriate amount of sulfur, only to 30% of their volume to allow for a large headspace. Autoclave at 105°C for 20 min. Prior to inoculation add yeast extract, vitamins (sterilized by filtration) and sulfide from anoxic stock solutions prepared under 100% N2 gas atmosphere. The final pH of the complete medium should be around 4.0. 2. After inoculation, pressurize the cultivation vessels to 1 bar overpressure with sterile 80% H2 and 20% CO2 gas mixture. ## Allen's trace element solution 180 mg MnCl2 x 4 H2O 450 mg Na2B4O7 x 10 H2O 22 mg ZnSO4 x 7 H2O 5 mg CuCl2 x 2 H2O 3 mg Na2MoO4 x 2 H2O 3 mg VOSO4 x 2 H2O 1 mg CoSO4 x 7 H2O 1000 ml Distilled water 1. Adjust pH of final solution to 2 with 1 N HCl. ## Wolin's vitamin solution (10x) 20 mg Biotin 20 mg Folic acid 100 mg Pyridoxine hydrochloride 50 mg Thiamine HCl 50 mg Riboflavin 50 mg Nicotinic acid 50 mg Calcium D-(+)-pantothenate 1 mg Vitamin B12 50 mg p-Aminobenzoic acid 50 mg (DL)-alpha-Lipoic acid 1000 ml Distilled water