# 328: PYG MEDIUM WITH VOLATILE FATTY ACIDS


## Main sol. 328

5	g	Beef extract	
5	g	Trypticase (BBL)	
10	g	Yeast extract	
40	ml	**Mineral solution**	
0.5	g	(NH4)2SO4	
3.1	ml	**Fatty acid mixture**	
5	g	Glucose	
1	mg	Resazurin	
5	mg	Haemin (dissolved in 0.5 ml 1 N NaOH)	
0.2	ml	Vitamin K1 (0.5% sol. in ethanol)	
0.5	g	L-Cysteine HCl x H2O	
960	ml	Distilled water	

1. Adjust pH to 6.9.
2. Dissolve ingredients except cysteine-HCl in water, boil for 5 min, cool to room temperature while gassing with 100% CO2, add cysteine-HCl and adjust pH to 6.9 with 8 N NaOH while gassing is continued. Switch to 100% N2 gas after pH has reached the desired value, distribute in anaerobic tubes under nitrogen, and autoclave.


## Mineral solution

0.3	g	CaCl2 x 2 H2O	
0.48	g	MgSO4 x 7 H2O	
1	g	K2HPO4	
1	g	KH2PO4	
10	g	NaHCO3	
2	g	NaCl	
1000	ml	Distilled water	


## Fatty acid mixture

17	ml	Acetic acid	
6	ml	Propionic acid	
4	ml	n-Butyric acid	
1	ml	n-Valeric acid	
1	ml	iso-Valeric acid	
1	ml	iso-Butyric acid	
1	ml	DL-2-Methylbutyric acid