# 35: ACIDITHIOBACILLUS MEDIUM ## Main sol. 35 0.1 g NH4Cl 3 g KH2PO4 0.1 g MgCl2 x 6 H2O 0.14 g CaCl2 x 2 H2O 10 g Sulfur (powdered) 1000 ml Distilled water 1. Dissolve all ingredients, except the sulfur and adjust the pH to 4.2, then autoclave. For sterilization place the sulfur in screw-capped tubes or bottles, wet with a few drops of water and heat for 3 hours to 90 - 100°C in a water bath on each of three successive days. Before use, aseptically layer the sulfur onto the surface of autoclaved liquid basal medium. 2. Note: Incubate statically without shaking.