# 294: SYNTROPHUS HQGö1 MEDIUM


## Main sol. 294

0.2	g	KH2PO4	
0.25	g	NH4Cl	
1	g	NaCl	
0.4	g	MgCl2 x 6 H2O	
0.5	g	KCl	
0.15	g	CaCl2 x 2 H2O	
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	
1	ml	**Seven vitamins solution**	
0.3	g	Gentisic acid (2,5-Dihydroxybenzoic acid), sodium salt	
0.1	g	Na2S x 9 H2O	
1000	ml	Distilled water	

1. Dissolve ingredients (except carbonate, vitamins, gentisic acid and sulfide), then sparge medium with 80% N2 and 20% CO2 gas mixture for 30 - 45 min to make it anoxic. Dispense under same gas atmosphere in culture vessels and autoclave. Add vitamins (sterilized by filtration) and sulfide from sterile anoxic stock solutions prepared under 100% N2 gas and carbonate from a sterile anoxic stock solution prepared under 80% N2 and 20% CO2 gas mixture. Add gentisic acid (2,5-dihydroxybenzoic acid) from a sterile and neutralized 200 mM stock solution prepared under 100% N2 gas atmosphere. If necessary, adjust the final pH of the medium to 7.2.
2. Note: Addition of 10 - 20 mg sodium dithionite per liter (e.g. from 5% (w/v) solution, freshly prepared under N2 and filter-sterilized) may stimulate growth at the beginning. For transfers use 5 - 10% inoculum. Some cultures are shipped in semi-solid medium which stimulates growth at the beginning. For agar stabs 3.00 g/l agar are added to the complete medium from a sterile anoxic stock solution (2% w/v). Upon receipt add anoxically 1 - 2 ml of the recommended freshly prepared liquid medium to the agar tube and incubate for 3 - 5 days. After incubation transfer 0.5 ml of the resulting cell suspension in the liquid phase to tubes with liquid medium.


## 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	


## Seven vitamins solution

100	mg	Vitamin B12	
80	mg	p-Aminobenzoic acid	
20	mg	D-(+)-biotin	
200	mg	Nicotinic acid	
100	mg	Calcium pantothenate	
300	mg	Pyridoxine hydrochloride	
200	mg	Thiamine-HCl x 2 H2O	
1000	ml	Distilled water