FIG. 4.

16S rRNA gene copy number associated with abundant OTUs in recovered SIP fractions; (A) OTU-11, (B) OTU-12, (C) OTU-19, and (D) OTU-41. -○-, fractions from incubations with ¹³C-anthracene; —●—, fractions from incubations with unlabeled anthracene. Each point represents a single qPCR and separate lines are for duplicate incubations. The horizontal dashed line in each panel indicates the quantification limit of the assay and qPCR values below that threshold were increased to that limit for the purposes of presenting the data. The shaded area indicates fractions identified as containing heavy DNA and combined to generate clone libraries.