Hydrocarbon degrading microbial communities in bench scale aerobic biobarriers for gasoline contaminated groundwater treatment

•Gasoline contaminated water was treated in a bench scale biobarrier.•The treatment was performed with and without the addition of a microbial inoculum.•The presence of the microbial inoculum did not increase the removal efficiency.•The taxonomic composition and the degradation potential were assessed.•The inoculum did not persist neither increased the degradation potential.