447. OCEANISPIROCHAETA MEDIUM (OsM)

Trypticase peptone (BD BBL) 2.0 g

Yeast extract 1.0 g

Na-resazurin solution (0.1% w/v) 0.5 ml

Na-thioglycolate 1.0 g

D-xylose 5.0 g

Charcoal-filtered, natural seawater 800.0 ml

Distilled water 200.0 ml

Dissolve ingredients except thioglycolate, then sparge medium with 100% N₂ gas for 30 – 45 min to make it anoxic. Add thioglycolate and adjust pH of medium to 7.5 with 10 N KOH. Dispense medium under 100% N₂ gas atmosphere into anoxic Hungate-type tubes or serum vials and autoclave at 121°C for 15 min. Add D-xylose from a sterile anoxic stock solution prepared under 100% N₂ gas atmosphere and sterilized by filtration.