Table 3. A caulinodans hyq operon expression; PhyqR β-glucuronidase reporter activity.

Strain	Atmosphere	N-source(s)
		N2 only	+5 mM NH4 +	+5 mM NH4 +
		(atm = 78+%)		+05 mM L-glutamine
66205	2% O2	1410±200	220±35	<10
	21% O2		<10	<10
66210 nifA	2% O2	40±10	40±10	<10
	21% O2		<10	<10

^anmol 5-bromo-4-chloro-3-indole min⁻¹ mg protein⁻¹.