Impact of bacteriophage MS2 adsorption on biofilm microbial communities, metabolic pathways, and protein expression...

The stability of microbial communities within sewer systems is essential for maintaining effluent quality and infrastructure longevity. However, the functional consequences of viral interactions with biofilms remain poorly characterised. This study examines the effects of bacteriophage MS2 adsorption on biofilm structure, metabolism, and pathogenic potential in a simulated 1 km sewer pipeline. Quartz crystal microbalance with dissipation monitoring (QCM-D) revealed irreversible phage adsorption onto extracellular polymeric substances (EPS), inducing a biphasic viscoelastic response. During the first 24 h, the ΔD/Δf slope increased from 0.204 to 0.420, indicating initial loosening of the EPS matrix. This was followed by a compaction phase, with the slope decreasing to 0.102 by 96 h. Metagenomic profiling indicated a shift in community functionality, with sulphur-metabolising Chlorobium decreasing by 27.8 % and the pathogenic genus Novosphingobium increasing by 4.87 %. Corresponding trends were observed in enzymatic activity: sulphate reduction genes (e.g., EC 2.7.7.4) declined to 10 % of baseline levels at 24 h, before recovering to 14542 annotations at 96 h. Metaproteomic analysis revealed divergent regulatory responses, with acetyl-CoA synthetase (EC 6.2.1.1) transcriptionally upregulated, while phosphate acetyltransferase (EC 2.3.1.8) increased independently of gene expression, indicating potential post-translational control. These findings demonstrate that phage adsorption perturbs biofilm integrity and reprogrammes microbial metabolism, underscoring the need for virus-informed strategies in sewer monitoring and pathogen management.