TABLE 4.

Nitrate reductase activity of narG, narX, and narK2 mutants

Strain	Genotype	Nitrite concna
		Aerobicb	NRP-1c	SSPd
Wild type	Wild type	140 ± 10	1,400 ± 49	1,900 ± 410
RVW1	ΔnarG	3 ± 1	2 ± 1	4 ± 2
RVW1(pNarGHJI1)e	ΔnarG + narG	160 ± 12	1,700 ± 72	1,000 ± 150
RVW2	ΔnarX	150 ± 7	1,400 ± 34	2,600 ± 350
RVW3	ΔnarK2	110 ± 8	35 ± 5	910 ± 80

^aNitrate reductase activity as measured by the nitrite concentration (micromolar). Values are means ± standard deviations.

^bAfter 112 h of growth (OD₅₈₀ of ∼0.4).

^cAfter 112 h, approximately 45 h in NRP-1 (OD₅₈₀ of 0.1).

^dAfter 280 h of growth (OD₅₈₀ > 1.0).

^eStrain RVW1 (ΔnarG) with plasmid pNarGHJI1 (narG) regained Nar activity.