[en] In this research, bacterial communities developing on marine plastics were analysed by several approaches (DGGE and sequencing) to see their potential ability to grow on plastic but also to degrade it. These plastic-degrading bacteria were enriched using cultivation media with low carbon contents and in presence of plastic films (LDPE, PET, PS and PVC). After 2 months of cultivation, one bacterial strain was enriched on LDPE: Alcanivorax borkumensis. This bacterium is known for its ability to degrade hydrocarbon chains and is a promising candidate for LDPE degradation. Its ability to depolymerize plastics and assimilate plastic monomers are studied.