ABSTRACT
Freshwater ecosystems are not closed or sterile environments. They support complex and highly dynamic microbiological communities strongly structured by their local environment. Growing city populations and the process of urbanization is predicted to strongly alter freshwater environments. To determine the changes in freshwater microbial communities associated with urbanization, full-length 16S rRNA gene PacBio sequencing was performed on DNA from surface water and sediments from five lakes and a wastewater treatment plant in the Berlin-Brandenburg region of Germany. Water samples exhibited highly environment specific bacterial communities with multiple genera showing clear urban signatures. We identified potential harmful bacterial groups that were strongly associated with environmental parameters specific to urban environments such as Clostridium, Neisseria, Streptococcus, Yersinia and the toxic cyanobacterial genus Microcystis. We demonstrate that urbanization can alter natural microbial communities in lakes and promote specific bacterial genera which include potential pathogens. Urbanization, creates favourable conditions for pathogens that might be introduced by sporadic events or shift their proportions within the ecosystem. Our findings are of global relevance representing a long-term health risk in urbanized waterbodies at a time of global increase in urbanization.
Competing Interest Statement
The authors have declared no competing interest.
