Fig 3.

Relative abundance of the OTUs in 16S rRNA gene clone libraries. (A) Bacterial classes enriched by petroleum hydrocarbons. (B) Hydrocarbon-enriched bacterial genera detected in contaminated microcosms. To simplify the interpretation of the scheme, only the hydrocarbon-enriched bacterial communities are shown, and bacterial groups with low abundance were clustered in unclassified bacteria and other groups. The taxonomy was assigned using the Greengenes (32) 16S rRNA gene database, and an average of 67 sequences per contaminated sample was obtained. The samples are denoted as follows: the first letter corresponds to the origin of each sample (J, Jacarepiá Lagoon; M, Massambaba Beach; V, Vermelha Lagoon), the second letter indicates the hydrocarbon used in the different microcosms (H, heptadecane; N, naphthalene; O, crude oil), and the third letter represents either the DNA (D)- or RNA (R)-based library.