Diversity and composition of sediment microbial assemblages in an Atlantic port environment

Sampling

Under the framework of the PORTONOVO cooperation which endeavors to enhance monitoring of environmental quality in ports along the Atlantic coast of Europe, we assessed microbial diversity and composition in a Portuguese port environment (Ria de Aveiro). Samples were collected in five locations: two within the port, two along the channel adjacent to the port and one in a relatively undisturbed reference location. Bacterial composition differed significantly among locations with the most pronounced difference being recorded between samples from the reference site versus both port locations. Samples taken from the channel adjacent to the port were intermediate in composition. The port samples were, furthermore, associated with higher values of nitrates, phosphates and total organic carbon; abundant bacterial OTU's (= 50 sequences) were also much more prevalent. Dominance as indicated by the relative abundance of the most abundant OTU was also pronounced in samples from port locations. Port and channel locations were associated with higher relative abundances of Actinobacteria, Deltaproteobacteria (particularly Desulfobacterales) whereas non-port locations had higher relative abundances of Flavobacteria and Rhodobacterales. Our results indicate that the port environment has a pronounced effect on bacterial composition, with sediment from areas under intense port activity displaying a dominance of the Desulfobacterales order.

Method steps

1. Pipeline used: https://www.ebi.ac.uk/metagenomics/pipelines/4.1