Table 1.

Fixed and variable parameters of the growth conditions.

Fixed parameter		Variable parameters
Incubation temperature	15°C	Medium	1/10 MB
pH	7.2		Stanier mineral medium
Buffering agent	Hepes	C-sources	Glucose
NH+4 background concentration	4 mM		Succinate-ethanol- glycerol
Fe(III)Na EDTA	40 μM		Pyruvate-acetate
Vitamin solution	1 ml/L	N-sources	KNO3
Medium	NSW		KNO3/KNO2
N concentration	5 mM	C:N ratio (Molar C:N)	5 or 25
Atmosphere	anaerobic	Signaling factor	cAMP