Fig. 4. Decreased diversity of car tank lid samples in enriched cultures with gasoline or diesel as the sole carbon source.

Hydrocarbon-containing enriched cultures resulting from the inoculum from vehicle 1 (diesel) (a, b) and vehicle 16, fueled with gasoline (c, d) after a week of incubation in a chamber and shaking at 30 °C, in the dark (a, c); and after four consecutive weekly passes under the same incubation conditions (b, d). 1NDC negative diesel control replica 1; 1C control minimal medium without fuel, inoculated with sample 1D; 1D diesel medium inoculated with sample 1D. 1NGC negative gasoline control replica 1; 16 C control minimal medium without fuel, inoculated with sample 16 G; 16 G gasoline medium inoculated with sample 16 G. e Genus-level taxonomy of three enriched diesel samples.