Effects of copper on biofilm formation in strains of the genus Enterococcus isolated from an aquatic ecosystem under anthropogenic stress

Bacteria of the genus Enterococcus can enter an uncultivated but viable state or form biofilms in order to survive in adverse conditions. A biofilm is a porous and complex structure formed by one or more species of microorganisms, organized into several layers irreversibly attached to a biotic or abiotic surface and enclosed in a matrix consisting of extracellular polymeric substances. The aim of this study is to investigate the effects of copper on biofilm formation in strains of the genus Enterococcus isolated from an aquatic ecosystem under anthropogenic stress. A study of biofilm formation in 30 strains of the genus Enterococcus isolated from anthropogenic aquatic ecosystems from March 10, 2018 to September 24, 2020 revealed that the morphology of biofilms varies depending on the presence of copper, their concentration and the type of enterococci (E. faecalis and E. faecium).