Metagenome study of microbial community

In this study, water and biofilm samples were collected from the main channel of the Danube River upstream and downstream of a large city, from a regulated side arm within an urbanized region, and from two differently separated oxbow lakes located in nature conservation areas. Among physical and chemical parameters, temperature, pH, electrical conductivity, dissolved oxygen, orthophosphate, total organic carbon, and nitrate of the water samples were measured. The taxonomic diversity of bacterial communities was determined using 16S rRNA gene-based amplicon sequencing using Illumina MiSeq platform. As shown in the results of the first comprehensive study on the Hungarian section of the Danube River, both the planktonic and biofilm communities were dominated by phyla Pseudomonadota, Actinobacteriota and Bacteroidota. Human impacts were mainly reflected in the composition of the slowly changing biofilm compared to the planktonic bacterial communities. The genera with pollution tolerance and/or degradation potential, such as Acinetobacter, Pseudomonas and Shewanella were detected mainly in biofilm communities in the highly urbanized section of the river.