# 76: GOTTSCHALKIA MEDIUM


## Main sol. 76

0.67	g	KOH	
0.91	g	K2HPO4	
2	g	Uric acid	
0.25	g	MgSO4 x 7 H2O	
15	mg	CaCl2 x 2 H2O	
6	ml	FeSO4 x 7 H2O (0.1% w/v in 0.1 N H2SO4)	
1	ml	**Trace element solution SL-10**	
1	ml	**Selenite-tungstate solution**	
1	g	Yeast extract	
0.5	ml	Sodium resazurin (0.1% w/v)	
1.5	g	Na2CO3	
0.5	g	Na-thioglycolate	
1000	ml	Distilled water	

1. First dissolve KOH and K2HPO4 in water, then add uric acid and boil until the acid is dissolved. Cool medium to room temperature under 100% N2 gas atmosphere and add all other compounds, except carbonate and thioglycolate. Dispense under 100% N2 gas atmosphere into anoxic Hungate-type tubes or serum vials and autoclave for 15 min at 121°C. Then add carbonate (filter-sterilized stock solution prepared under 80% N2 and 20% CO2 gas atmosphere) and thioglycolate (stock solution, autoclaved separately under 100% N2 gas). Adjust pH of complete medium to 7.0 - 7.5, if necessary.


## Trace element solution SL-10

10	ml	HCl (25%)	
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	
990	ml	Distilled water	

1. First dissolve FeCl2 in the HCl, then dilute in water, add and dissolve the other salts. Finally make up to 1000.00 ml.


## Selenite-tungstate solution

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