20.500.12556/DiRROS-29951 Physicochemical and antimicrobial characterization of nanobubbles reveals physical disruption is the primary mode of biofilm inactivation Biofilm-associated contamination represents a persistent and costly challenge across environmental systems, causing reduced efficacy of disinfectants. Recently, nanobubbles (NBs) have shown promise for biofilm decontamination; yet, their underpinning mode of action remains a topic of debate. In this study, the interaction of air-generated NBs with Escherichia coli and Staphylococcus aureus biofilms was investigated. NBs were generated using a venturi nozzle and characterized using Nanoparticle Tracking Analysis, revealing a NB density of 5.66 × 108 particles/mL and a mean diameter of 84 nm. Application of NB solution to microbial biofilms resulted in a 2.16 log reduction for E. coli and 1.52 log reduction for S. aureus, along with visible morphological changes such as cell collapse, wrinkling, and matrix disruption. ESR spin trapping confirmed hydroxyl radical formation, but intracellular ROS and lipid peroxidation levels were minimal and, in some cases, not significantly different from Milli-Q water controls. After 28 days, NBs remained present and continued to demonstrate antimicrobial activity, biofilm disruption, and some ROS activity. These findings indicate that although hydroxyl radicals are generated, oxidative stress is not the dominant antimicrobial mechanism under the examined conditions, suggesting physical biofilm disruption is the primary mode of action. nanobubbles ultrafine bubbles reactive oxygen species hydroxyl radicals biofilms nanomehurčki reaktivne kisikove vrste radikali biofilmi true false true American Chemical Society ZDA Angleški jezik Slovenski jezik © 2026 The Authors. Neznano 2026-06-10 10:08:01 2026-06-10 10:08:02 2026-06-11 03:47:34 0000-00-00 00:00:00 2026 0 0 Nasl. z nasl. zaslona; Soavtorji iz Slovenije: Matjaž Gomilšek, Martina Modic, Damjan Vengust, Andrej Zorko, Uroš Cvelbar; Opis vira z dne 9. 6. 2026; str. A-L iss. Vol. 6 [in press] 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 2026-02-20 2026-05-21 2026-06-01 53 2690-0637 10.1021/acsestwater.6c00252 280960515 https://pubs.acs.org/doi/10.1021/acsestwater.6c00252 1 81de8a0a-64a3-11f1-9215-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=45108 RAZ_Northage_Naomi_2026.pdf RAZ_Northage_Naomi_2026.pdf 1 2679323D47B2B25BDB9F63012599B995 697f8849bdb66dec5fd2cb9dee38ce3ab8c910160dd5249d1ab2d478945fca53 644ea31f-64a4-11f1-9215-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=45109 Institut Jožef Stefan 0 0 0