265. ECTOTHIORHODOSPIRA VARIABILIS MEDIUM

NaCl 50.00 g

Na₂CO₃ 5.00 g

NaHCO₃ 15.00 g

KCl 0.10 g

K₂HPO₄ 0.50 g

MgCl₂ × 6 H₂O 0.20 g

NH₄Cl 0.50 g

Na₂S × 9 H₂O 0.50 g

Na₂S₂O₃ × 5 H₂O 0.50 g

Yeast extract 0.10 g

Na acetate 0.50 g

Trace element solution SL-10 (see below) 1.00 ml

Vitamin B₁₂ 20.00 mkg

Distilled water 1000.00 ml

Trace element solution SL-10:

HCl (25%; 7.7 M) 10.0 ml

FeCl₂ × 4 H₂O 1.5 g

ZnCl₂ 70.0 mg

MnCl₂ × 4 H₂O 100.0 mg

H₃BO₃ 6.0 mg

CoCl₂ × 6 H₂O 190.0 mg

CuCl₂ × 2 H₂O 2.0 mg

NiCl₂ × 6 H₂O 24.0 mg

Na₂MoO₄ × 2 H₂O 36.0 mg

Distilled water 990.0 ml

The trace element solution preparation: FeCl₂ × 4 H₂O is dissolved firstly in HCl, and then is mixed with water and other salts are dissolved in the sequence indicated.

Prepare and boil the medium in the absence of Na₂S × 9 H₂O, NaHCO₃, vitamin B₁₂, CaCl₂ × 2 H₂O, MgCl₂x 6 H₂O. Cool under a stream of nitrogen and add the remaining components, except vitamin B₁₂ and Na₂S₂O₃ × 5 H₂O. Dispense into tubes or bottle fitted with rubber stoppers and autoclave. Add the vitamin B₁₂ (filter sterilised) and Na₂S₂O₃ × 5 H₂O from sterile stock solutions.

Final pH 9.0 – 9.5

Autoclave at 121°C for 15 min.