FIG. 3.

Correlations between target and naphthalene concentrations in Chattanooga Creek sediment samples. (A) Copies of the nagAc-like gene target per microgram of DNA (y = 4.14 + 0.55x, r² = 0.747); (B) copies of the nagAc-like gene target per gram dw (y = 5.65 + 0.72x, r² = 0.586); (C) copies of the bacterial 16S rRNA gene per microgram of DNA (y = 9.11 − 0.023x, r² = 0.021); (D) copies of the bacterial 16S rRNA gene per gram dw (y = 10.62 + 0.16x, r² = 0.128). Values of copies of the target per gram dw were corrected by DNA recovery calculated based on real-time PCR quantification of the spiked luxE gene, as indicated in Materials and Methods. Dashed lines, 95% confidence intervals; error bars, standard deviations of triplicate DNA extractions.