Inactivation of Listeria monocytogenes and Enterococcus faecalis by Bubble-Based Plasma Treated Water : Reactive Species Characterization and Numerical Simulation Insights

Abstract

The rise of antibacterial resistance represents a major global challenge affecting human health and food production systems. Plasma treated water (PTW) was assessed as a sustainable antimicrobial technology. PTW was generated via a bubble-based approach at air flows of 60, 80, 100 and 120 slm and evaluated against Listeria monocytogenes and Enterococcus faecalis. Several reactive oxygen and nitrogen species (RONS) were detected; increasing airflow enhanced their diversity and concentration. PTW-120 delivered the highest antibacterial activity, coinciding with the highest spin-adduct levels measured by electron paramagnetic resonance (EPR). Numerical simulations of bubble dynamics and air–water interfacial area supported enhanced RONS transfer at higher flows. These findings demonstrate that PTW is a viable, eco-friendly and antimicrobial alternative without harmful chemical residues.