# 929: RHODOVULUM IODOSUM AND R. ROBIGINOSUM MEDIUM


## Main sol. 929

26.4	g	NaCl	
5.7	g	MgCl2 x 6 H2O	
6.8	g	MgSO4 x 7 H2O	
1.5	g	CaCl2 x 2 H2O	
0.66	g	KCl	
0.09	g	KBr	
1000	ml	Distilled water	

1. Prepare the medium anaerobically under an atmosphere of N2:CO2 (8:2 vol:vol) and then add:

30	ml/l	NaHCO3 (84 g/l autoclaved under a CO2 atmopshere)	
0.4	g/l	KH2PO4	
0.25	g/l	NH4Cl	
0.5	mM	Na2S2O3	
1	ml/l	**Trace elements**	
1	ml/l	**Selenite/tungsate solution**	
1	ml/l	** Vitamin solution**	
1	ml/l	**Vitamin B12 solution 0.05 g/L**	
1	ml/l	**Vitamin B1 solution 0.1 g/L**	
5	mM	Acetate	
10	mM	FeSO4	

2. The pH is adjusted to 6.8
3. To the medium add 5 mM acetate and 10 mM FeSO4 (from a 1 M stock solution kept under nitrogen). When the iron is added to the medium a white floculant precipitate may appear. In the initial stages of growth the precipitate turns orange/brown as the ferrous ions are oxidised to ferrihydrite. Cultivation may take 2-3 weeks at a distance of 30 cm from a 25 W light bulb.


## Trace elements

2.1	g	FeSO4 x 7 H2O	
5.2	g	Na2-EDTA	
30	mg	H3BO3	
100	mg	MnCl2 x 4 H2O	
190	mg	CoCl2 x 6 H2O	
24	mg	NiCl2 x 6 H2O	
2	mg	CuCl2 x 2 H2O	
144	mg	ZnSO4 x 7 H2O	
36	mg	Na2MoO4 x 2 H2O	
1000	ml	Distilled water	

1. Adjust the pH to 6.0


## Selenite/tungsate solution

6	mg	Na2SeO3 x 5 H2O	
8	mg	Na2WO4 x 2 H2O	
200	mg	NaOH	
1000	ml	Distilled water	


##  Vitamin solution

4	mg	Para-aminobenzoic acid	
1	mg	Biotin	
10	mg	Nicotinate	
5	mg	Pantothenate	
15	mg	Pyridoxin	
100	ml	Distilled water	


## Vitamin B12 solution 0.05 g/L

5	mg	Cyanocobalamine	
100	ml	Distilled water	


## Vitamin B1 solution 0.1 g/L

10	mg	Thiamine	
100	ml	Distilled water