PMC

Relative abundance of the OTUs shared among the different enriched microcosms. The samples are denoted as follows: the first letter represents the origin of the samples (J, Jacarepiá Lagoon; M, Massambaba Beach; V, Vermelha Lagoon), followed by the hydrocarbon used in the different microcosms (H, heptadecane; N, naphthalene; O, crude oil). *, low-abundance OTUs are grouped as “other.”

An RDA ordination diagram based on the genetic fingerprint data obtained from hydrocarbon-enriched bacterial communities. The data were plotted using each aquatic ecosystem type, and the different colors represent the microcosm samples obtained from Vermelha Lagoon (VER; green), Massambaba Beach (MAS; blue), and Jacarepiá Lagoon (JAC; red). The detailed genetic fingerprint pattern is presented in Fig. S2B in the supplemental material.

TPH quantification after the 32nd day of incubation of the microcosms. The degradation values (above the bars) were determined as the ratio between the average values obtained for the contaminated microcosms and those obtained for the negative controls used in this study. The samples are denoted as follows: the first letter represents the origin of the sample (J, Jacarepiá Lagoon; M, Massambaba Beach; V, Vermelha Lagoon), followed by the hydrocarbon used in the different microcosms (H, heptadecane; N, naphthalene; O, crude oil).

(A) Phylogenetic tree based on the 16S rRNA gene sequences of five selected bacterial isolates and the closest related species obtained from the GenBank database (NCBI). The tree was constructed on the basis of the neighbor-joining method. The GenBank accession number of each bacterial species is presented between vertical lines. (B) Number of CFU ml⁻¹ after bacterial growth in different concentrations of NaCl for 4 days using heptadecane as the sole carbon source. ^a, similar results were obtained for strain F02-115.1_JO; ^b, similar results were obtained for strain MOM4_MO.

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 () 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.