Pablos, C.Govaert, M.Angarano, V.Smet, C.Marugán, J.Van Impe, J.F.M2022-02-092022-02-092021C. Pablos, M. Govaert, V. Angarano, C. Smet, J. Marugán, J.F.M. Van Impe, Photocatalytic inactivation of dual- and mono-species biofilms by immobilized TiO2, Journal of Photochemistry and Photobiology B: Biology, Volume 221, 2021, 112253, ISSN 1011-1344, https://doi.org/10.1016/j.jphotobiol.2021.1122531011-1344http://hdl.handle.net/10115/18631Biofilms formed by different bacterial species are likely to play key roles in photocatalytic resistance. This study aims to evaluate the efficacy of a photocatalytic immobilized nanotube system (TiO2-NT) (IS) and suspended nanoparticles (TiO2-NP) (SS) against mono- and dual-species biofilms developed by Gram-negative and Gram-positive strains. Two main factors were corroborated to significantly affect the biofilm resistance during photocatalytic inactivation, i.e., the biofilm-growth conditions and biofilm-forming surfaces. Gram-positive bacteria showed great photosensitivity when forming dual-species biofilms in comparison with the Gram-positive bacteria in single communities. When grown onto TiO2-NT (IS) surfaces for immobilized photocatalytic systems, mono- and dual-species biofilms did not exhibit differences in photocatalytic inactivation according to kinetic constant values (p > 0.05) but led to a reduction of ca. 3–4 log10. However, TiO2-NT (IS) surfaces did affect biofilm colonization as the growth of mono-species biofilms of Gram-negative and Gram-positive bacteria is significantly (p ≤ 0.05) favored compared to co-culturing; although, the photocatalytic inactivation rate did not show initial bacterial concentration dependence. The biofilm growth surface (which depends on the photocatalytic configuration) also favored resistance of mono-species biofilms of Gram-positive bacteria compared to that of Gram-negative in immobilized photocatalytic systems, but opposite behavior was confirmed with suspended TiO2 (p ≤ 0.05). Successful efficacy of immobilized TiO2 for inactivation of mono- and dual-species biofilms was accomplished, making it feasible to transfer this technology into real scenarios in water treatment and food processing.engAttribution-NonCommercial-NoDerivatives 4.0 Internacionalhttp://creativecommons.org/licenses/by-nc-nd/4.0/BiofilmsPhotocatalysisImmobilized TiO2TiO2 nanotubesSalmonellaListeriainfo:eu-repo/semantics/article10.1016/j.jphotobiol.2021.112253info:eu-repo/semantics/openAccess