# 1667: HYPNOCYCLICUS MEDIUM ## Main sol. 1667 0.02 g Na2SO4 1 g KH2PO4 0.1 g NH4Cl 20 g NaCl 3 g MgCl2 x 6 H2O 0.5 g KCl 0.15 g CaCl2 x 2 H2O 0.7 g NaNO3 1 g Yeast extract 1 ml **Trace element solution SL-10** 0.5 ml Sodium resazurin (0.1% w/v) 1.5 g Na2CO3 1 ml **Seven vitamins solution** 0.5 g Na2S x 9 H2O 1000 ml Distilled water 1. Dissolve all ingredients except carbonate, vitamins and sulfide, then sparge medium with 80% N2 and 20% CO2 gas mixture for 30 - 45 min to make it anoxic. Dispense medium under same gas atmosphere into anoxic Hungate-type tubes or serum vials and autoclave. Add vitamins and sulfide from sterile anoxic stock solutions prepared under 100% N2 gas and carbonate from a sterile anoxic stock solution prepared under 80% N2 and 20% CO2 gas atmosphere. Vitamins should be sterilized by filtration. Adjust pH of complete medium to 6.8 - 7.2, if necessary. ## Trace element solution SL-10 10 ml HCl (25%) 1.5 g FeCl2 x 4 H2O 70 mg ZnCl2 100 mg MnCl2 x 4 H2O 6 mg H3BO3 190 mg CoCl2 x 6 H2O 2 mg CuCl2 x 2 H2O 24 mg NiCl2 x 6 H2O 36 mg Na2MoO4 x 2 H2O 990 ml Distilled water 1. First dissolve FeCl2 in the HCl, then dilute in water, add and dissolve the other salts. Finally make up to 1000.00 ml. ## Seven vitamins solution 100 mg Vitamin B12 80 mg p-Aminobenzoic acid 20 mg D-(+)-biotin 200 mg Nicotinic acid 100 mg Calcium pantothenate 300 mg Pyridoxine hydrochloride 200 mg Thiamine-HCl x 2 H2O 1000 ml Distilled water