Oxidative stress: an unutilised mechanism for whole-cell biocatalysis of emerging wastewater micropollutants

This project investigates oxidative stress as a novel mechanism to enhance microbial biocatalysis of emerging organic micropollutants (OMPs), including pharmaceuticals, pesticides, and personal care products in wastewater. Aerobic microbial respiration generates reactive oxygen species (ROS), which activate antioxidant responses involving oxidoreductases such as peroxidases and cytochrome P450s—enzymes capable of transforming a wide range of OMPs. We explored how environmental triggers, including dynamic dissolved oxygen (DO) perturbations and exogenous ROS exposure, modulate these enzymatic pathways in farm and municipal sludge microbiomes. A key focus was the role of the neuroactive hormone L-norepinephrine (L-NE) in inducing oxidative stress and influencing microbial growth and metabolism. Exposure to L-NE (5×10?5 M) enhanced bacterial proliferation and the expression of oxidative stress genes (oxyR, soxRS), alongside the upregulation of oxidoreductases and autoinducer synthesis genes (luxS). These effects correlated with the enrichment of OMP-degrading proteobacterial families such as Pseudomonadaceae, Rhodocyclaceae, and Sphingomonadaceae. This study employed high-throughput multi-omics approaches, including metagenomics, to identify redox-responsive microbial genes and pathways across oxidative regimes. The submitted FASTA files represent metagenomic sequences from microbial communities subjected to oxidative perturbations, including L-NE treatment. These datasets provide valuable insight into the molecular basis of stress-induced biocatalysis and inform strategies for environmentally adaptive wastewater treatment.