Table 1.

Concentrations of complex nitrogen sources in modified MRS broth

Dilutions of nitrogen sources in relation to MRS broth	Complex nitrogen sources (g/l)
	Yeast extract	Meat extract	Pepton K
10x	0.40	0.80	1.0
25x	0.16	0.32	0.4
50x	0.08	0.16	0.2
75x	0.05	0.11	0.13
100x	0.04	0.08	0.10
500x	0.01	0.02	0.02