We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Nanoplastics induce prophage activation and quorum sensing to enhance biofilm mechanical and chemical resilience
Summary
Researchers found that polystyrene nanoplastics at environmentally relevant concentrations promote the formation of more resilient bacterial biofilms by triggering viral activation and cell-to-cell communication within microbial communities. The nanoplastics caused oxidative stress that activated dormant viruses within bacteria, which in turn stimulated protective biofilm production with enhanced resistance to chlorine disinfection. The findings suggest that nanoplastic pollution could make harmful bacterial communities in water systems harder to eliminate through standard treatment methods.
Despite the prevalence of nanoplastics (NPs) in natural and engineered water systems and their association with microbial risks, bacterium-phage interactions have been largely overlooked in the context of biofilm formation. Here, we investigated the effects of positively (PS-NH₂) and negatively (PS-COOH) charged polystyrene nanoplastics (PS-NPs) on dual-species biofilms composed of Escherichia coli (λ+) and Pseudomonas aeruginosa. PS-NPs promoted biofilm formation and stability at environmentally relevant concentrations (e.g., 100-1000 ng/L), with PS-NH₂ exhibiting higher influence. The cellular internalization of PS-NPs increased the reactive oxygen species (ROS) levels by 2.18-2.25 folds, triggered prophage λ activation followed by lysis of E. coli (λ+) after exposure to PS-NPs. Transcriptomic analyses revealed that PS-NPs, especially PS-NH₂, activated the SOS response (2.35-2.63-fold), λ phage replication (2.68-3.97-fold), and interspecies quorum sensing (2.24-5.13-fold), which was verified by the proteomic analyses. Therefore, PS-NPs stimulated protective extracellular polymeric substances (EPS) secretion with eDNA content increased to 325.8-433.8 μg/cm. Enhanced EPS production contributed to improved biofilm mechanical properties (1.46-1.57-fold as measured by atomic force microscopy) and increased resistance to chlorine disinfection. Metagenomic analysis of pipeline biofilm demonstrated that PS-NPs promoted bacterium-phage interactions and enhanced bacterial antiviral defense systems, which stimulated multi-species biofilm formation and enhanced environmental resilience. Overall, our findings provide novel insights into the interplay between nanoplastics and bacterium-phage dynamics, highlighting increased microbial risks associated with waterborne nanoplastics.
Sign in to start a discussion.