Understanding the dynamics of a microbial consortium prior to and post the introduction of specific antiretroviral compounds in a moving bed biofilm reactor system

The use of moving bed biofilm reactor (MBBR) systems for the treatment of municipal and industrial wastewater has been shown to gain more attention, in contrast to activated sludge systems. However, little is known about the effects of pharmaceuticals on constituent microbial communities. This study investigated the shift in microbial community compositions of biofilms in an MBBR due to exposure to specific antiretroviral (ARV) compounds. Microbial diversity (alpha-diversity) of seeded sludge from a full-scale municipal wastewater treatment plant and biofilm samples from a laboratory-scale MBBR system during pre- and post-introduction of ARV compounds was investigated by Illumina sequencing of the 16S rRNA gene. Microbial diversity results demonstrated that the introduction of ARV drugs affects the bacterial community composition and diversity considerably. For instance, the genus <i>Nitrosomonas</i>, <i>Nitrospira</i>, and <i>Alicycliphilus</i> was found to be higher in post-introduction of ARV compounds biofilm samples than in biofilm samples before the introduction of ARV compounds.