# 1100: DESULFACINUM MEDIUM


## Main sol. 1100

3	g	Na2SO4	
0.2	g	KH2PO4	
0.3	g	NH4Cl	
7	g	NaCl	
1	ml	**Trace element solution SL-11**	
1	ml	**Selenite-tungstate solution**	
3.1	g	MgCl2 x 6 H2O	
0.5	g	KCl	
0.15	ml	CaCl2 x 2 H2O	
0.5	g	Yeast extract	
0.5	ml	Sodium resazurin (0.1% w/v)	
1.5	g	NaHCO3	
2	g	Na-L-lactate	
15	ml	**Neutralized sulfide solution 3% (w/v)**	
1000	ml	Distilled water	

1. Dissolve ingredients (except bicarbonate, lactate and sulfide) and sparge medium with 100% N2 gas 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 lactate and sulfide form sterile anoxic stock solutions prepared under 100% N2 gas and bicarbonate from a sterile anoxic stock solution prepared under 80% N2 and 20% CO2 gas mixture. Adjust pH of the complete medium to 7.2, if necessary.


## Trace element solution SL-11

5.2	g	Na2-EDTA x 2 H2O	
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	
1000	ml	Distilled water	

1. Dissolve EDTA in 800 ml distilled water, adjust pH to 7 using 2 N NaOH and add ferrous chloride. After ferrous chloride has dissolved add other compounds. Finally adjust pH to 6.0 and bring volume to 1000 ml. 


## Selenite-tungstate solution

0.5	g	NaOH	
3	mg	Na2SeO3 x 5 H2O	
4	mg	Na2WO4 x 2 H2O	
1000	ml	Distilled water	


## Neutralized sulfide solution 3% (w/v)

3	g	Na2S x 9 H2O	
100	ml	Distilled water	

1. The sulfide solution is prepared in a 250 ml screw-capped bottle with a butyl rubber septum and a magnetic stirrer. The solution is bubbled with nitrogen gas, closed and autoclaved for 15 min. at 121°C. After cooling to room temperature the pH is adjusted to about 7.0 by adding of sterile 2 M H2SO4 drop-wise with a syringe without opening the bottle.