TABLE 3.

P. stutzeri nirS gene abundance in various habitats as measured by real-time PCR

Habitat	Sample no. or type	No of copies of P. stutzeri nirS DNA/μg of community DNAf		P. stutzeri nirS DNA (μg/g of community DNA)f
		Mean	Upper 95% CI	Mean	Upper 95% CI
Soila
KBS (Mich.)	0×	1.0 × 102		4.4 × 10−4
	1×	BDLg		BDL
	10×	BDL		BDL
	100×	BDL		BDL
Groundwater
Schoolcraft bioremediation site (Mich.)b	M8	BDL		BDL
	M11	1.1 × 1011		4.8 × 105
	M19	2.0 × 107		89
Shiprock UMTRAc site (N. Mex.)	425	1.9 × 103	3.7 × 103	8.4 × 10−3	1.6 × 10−2
	602	3.1 × 105	8.8 × 104	1.4	3.9 × 10−1
	603	2.2 × 105	2.1 × 104	9.7 × 10−1	9.3 × 10−2
	619	2.0 × 107	9.4 × 105	90	4.1
	813	5.0 × 106	4.5 × 105	22	2
	826	5.0 × 105	1.6 × 105	2.2	6.9 × 10−1
Freshwater sedimentd
Wintergreen Lake (Mich.)		2.2 × 106	3.1 × 105	9.7	1.3
Marine sedimente
Pacific Ocean (Wash.)	0–0.5 cm	BDL		BDL
	0.5–1 cm	BDL		BDL
	1–2 cm	1.0 × 102	2.0 × 102	4.4 × 10−4	8.8 × 10−4
	2–3 cm	BDL		BDL
	3–5 cm	BDL		BDL
	5–10 cm	BDL		BDL
Puget Sound (Wash.)	1–1.5 cm	BDL		BDL
	1.5–2 cm	2.1 × 104	2.4 × 103	9.1 × 10−2	1.0 × 10−2
	6–6.5 cm	7.0 × 102	2.0 × 102	3.1 × 10−3	8.8 × 10−4

^aSoils were treated with 0, 1, 10, and 100× the normal field rate (1.1 kg ha⁻¹) of the herbicide 2, 4-dichlorophenoxyacetate (1). 

^bSamples were collected 2 m upstream (M8), 1 m downstream (M11), and 2.5 m downstream (M19) from the well where P. stutzeri KC was injected (21). 

^cUMTRA, uranium mill tailings remedial action. 

^dThe surface 2 cm containing the active denitrifiers was analyzed. 

^eDepths within the sediment core are reported. 

^fResults are from triplicate samples when 95% confidence interval (CI) is indicated and from single samples, otherwise. 

^gBDL, below detection limit.