Interactions between Penicillium brevicompactum/Penicillium expansum and Acinetobacter calcoaceticus isolated from drinking water in biofilm development and control

Available online 13 October 2022
Bacteria and filamentous fungi (ff) are commonly encountered in biofilms developed in drinking water (DW) distribution systems (DWDS). Despite their intimate ecological relationships, researchers tend to study bacteria and ff separately. This work assesses the impact of bacteria-ff association in biofilm formation and tolerance to chlorination. One strain of Acinetobacter calcoaceticus isolated from DW was used as a model bacterium. Penicillium brevicompactum and P. expansum isolated from DW were the ff selected. Single species and inter-kingdom adhesion and biofilm formation occurred under two shear stress () conditions (0.05 and 1.6 Pa). The sessile structures were further characterized in terms of biomass production, respiratory activity and structure. The results showed that 1.6 Pa of shear stress and A. calcoaceticus-ff association favoured biofilm production. Inter-kingdom biofilms produced more biomass than A. calcoaceticus single species and reduced A. calcoaceticus susceptibility to disinfection, particularly to high sodium hypochlorite (SHC) concentrations. In addition, P. brevicompactum formed single species biofilms highly resistant to removal and inactivation by SHC. The presence of P. brevicompactum or P. expansum in inter-kingdom biofilms significantly decreased SHC removal and inactivation effects in comparison to the bacterial biofilms alone, proposing that using bacteria to form biofilms representative of DWDS can provide inaccurate conclusions, particularly in terms of biofilm production and susceptibility to disinfection.
This work was financially supported by LA/P/0045/2020 (ALiCE), UIDB/00511/2020 and UIDP/00511/2020 (LEPABE) - funded by national funds through the FCT/MCTES (PIDDAC); Projects Germirrad - POCI-01-0247-FEDER-072237; PRESAGE - Aquatic/0007/2020, funded by FEDER funds through COMPETE2020 – Programa Operacional Competitividade e Internacionalizaçao ˜ (POCI) and by national funds (PIDDAC) through FCT/MCTES; Project “HealthyWaters – Identification, Elimination, Social Awareness and Education of Water Chemical and Biological Micropollutants with Health and Environmental Implications”, with reference NORTE-01-0145-FEDER-000069, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This study was further supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and by LABBELS – Associate Laboratory in Biotechnology, Bioengineering and Microelectromechnaical Systems, LA/P/0029/2020.
info:eu-repo/semantics/publishedVersion