# 1611: YCFA MEDIUM (modified)


## Medium 1611 in Hungate tube

1. Prepare the Medium (see Main sol. 1611). Distribute under N2 into Hungate tubes (10 ml):

10	ml	**Main sol. 1611**	

2. Autoclave. Then filter sterilize vitamin solution and aseptically add 100 µl per Hungate tube:

0.1	ml	**Vitamin solution** (filter-sterilized)	


## Main sol. 1611

10	g	Casitone	
2.5	g	Yeast extract	
5	g	Glucose	
45	mg	MgSO4 x 7 H2O	
90	mg	CaCl2 x 2 H2O	
0.45	g	K2HPO4	
0.45	g	KH2PO4	
0.9	g	NaCl	
1	mg	Resazurin	
1000	ml	Distilled water	

1. Dissolve ingredients except NaHCO3, hemin, cysteine in water and boil for 10 min, then add fatty acids:

2.7	ml	**Volatile fatty acids**	

2. Cool down to room temperature while gassing with 100% CO2. Add the NaHCO3, hemin, cysteine.

4	g	NaHCO3	
1	g	L-Cysteine HCl	
10	mg	Hemin	

3. Adjust pH to 6.7-6.8.


## Volatile fatty acids

1.9	ml	Acetic acid	
0.7	ml	Propionic acid	
90	µl	iso-Butyric acid	
100	µl	n-Valeric acid	
100	µl	iso-Valeric acid	


## Vitamin solution

2	mg	Biotin	
2	mg	Folic acid	
10	mg	Pyridoxine hydrochloride	
5	mg	Thiamine-HCl x 2 H2O	
5	mg	Riboflavin	
5	mg	Nicotinic acid	
5	mg	D-Calcium pantothenate	
0.1	mg	Vitamin B12	
5	mg	p-Aminobenzoic acid	
5	mg	Lipoic acid	
1000	ml	Distilled water