The effects of silver particle size on bacterioplankton community and potential function in aquatic environment

Silver nanoparticles (AgNPs), known for their antimicrobial properties, are increasingly being recognized as a water pollutant, with their physicochemical properties varying based on particle size. However, there is a lack of research on whether presence of AgNPs and their particle size affect bacterial communities in water bodies. In this study, the water from Chaohu Lake was collected and spiked with AgNPS of different particle sizes of (5 nm, 50 nm, and 100 nm) to stimulate the microbial response. Our findings revealed that the presence of AgNPs could significantly disrupt bacterial community structure and strengthen the associations between certain bacteria, with significant impacts observed on nitrifying and denitrifying processes. Different particle sizes of AgNPs had various effects on bacterial community structure, with small -sized AgNPs affecting the bacterial community the most. Moreover, the presence of AgNPs and their varying particle sizes were observed to significantly affect the nitrogen cycle, carbon cycle, and respiration, thus imposing significant impacts on other ecological functions of aquatic ecosystems. This study provides a baseline study on the aquatic ecotoxicological effects of AgNPs.