SRP430176 PRJNA950420 Microbial colonization of plastics in the river We compared the microbial colonization of two types of plastics (biodegradable and non-biodegradable) and three natural substrata (leaves, sediments and rocks) in two study sites of an urban river differing in their degree of plastic contamination (upstream and downstream). To study differences in microbial colonization, we used functional descriptors such as extracellular enzymatic activities and structural descriptors such as prokaryotic and eukaryotic diversity.