Plastic trash is common in oceans. Terrestrial and marine ecosystem interactions occur in the intertidal zone
where accumulation of plastic frequently occurs. However, knowledge of the plastic-associated microbial community
(the plastisphere) in the intertidal zone is scanty. We used high-throughput sequencing to profile the
bacterial communities attached to microplastic samples from intertidal locations around the Yangtze estuary
in China. The structure and composition of plastisphere communities varied significantly among the locations.
We found the taxonomic composition on microplastic samples was related to their sedimentary and aquatic origins.
Correlation network analysis was used to identify keystone bacterial genera (e.g. Rhodobacterales,
Sphingomonadales and Rhizobiales), which represented important microbial associations within the
plastisphere community. Other species (i.e. potential pathogens)were considered as hitchhikers in the plastic attached
microbial communities.Metabolic pathway analysis suggested adaptations of these bacterial assemblages
to the plastic surface-colonization lifestyle. These adaptations included reduced “cellmotility” and greater “xenobiotics
biodegradation and metabolism.” The findings illustrate the diverse microbial assemblages that occur on
microplastic and increase our understanding of plastisphere ecology.