# 150a: ACIDITHIOBACILLUS CALDUS MEDIUM


## Main sol. 150a

3	g	(NH4)2SO4	
0.5	g	K2HPO4 x 3 H2O	
0.5	g	MgSO4 x 7 H2O	
0.1	g	KCl	
0.02	g	Ca(NO3)2 x 4 H2O	
10	ml	**Trace element solution**	
5	g	Sulfur (powdered)	
1000	ml	Distilled water	

1. Dissolve ingredients except trace elements and sulfur. Adjust pH with 6 N H2SO4 to 2.5, dispense into suitable cultivation vessels and autoclave. After autoclaving add filter-sterilized trace elements solution (see below) and sterile sulfur powder.  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 the autoclaved liquid basal medium.


## Trace element solution

1.1	g	FeCl3 x 6 H2O	
0.05	g	CuSO4 x 5 H2O	
0.2	g	H3BO3	
0.2	g	MnSO4 x H2O	
0.08	g	Na2MoO4 x 2 H2O	
0.06	g	CoCl2 x 6 H2O	
0.09	g	ZnSO4 x 7 H2O	
1000	ml	Distilled water