The effects of emerging environmental contaminants on Stenotrophomonas maltophilia isolated from drinking water in planktonic and sessile states

Concerns on the presence of emerging contaminants (ECs) in water sources have increased in recent years. The lack of efficient technologies to remove ECs from residual waters contributes for their appearance in drinking water distribution systems (DWDS). Therefore, sessile microorganisms on DWDS pipes are continuously exposed to trace concentrations of ECs. However, no data exists on the role of ECs on the resident microbiota. The present work aims to understand the effects of prolonged exposure of a bacterial strain of Stenotrophomonas maltophilia, isolated from a DWDS, in both planktonic and biofilm states, to trace concentrations of selected ECs (antipyrineANTP; diclofenac sodium saltDCF; ibuprofenIBP; galaxolideGAL; tonalideTON; carbamazepineCBZ; clofibric acidCA; tylosinTY) on its tolerance to sodium hypochlorite (NaOCl) and resistance to antibiotics. Pre-established S. maltophilia biofilms were exposed to ECs for 26 d. Subsequently, the planktonic behaviour of the biofilm cells grown in the presence of ECS was characterized in terms of susceptibility to NaOCl and to selected antibiotics (levofloxacin and trimethoprim-sulfamethoxazole). Moreover, S.maltophilia was tested on its biofilm productivity in the presence of ECs (alone and mixed). These biofilms were challenged by NaOCl in order to assess the role of ECs on biofilm susceptibility. The results did not evidence remarkable effects of ECs on planktonic S. maltophilia susceptibility to NaOCl and antibiotics. However, S. maltophilia biofilm production and susceptibility to NaOCl was affected from ECs pre-exposure, particularly by the combination of different ECs (CA+CBZ, CA+IBP, CA+CBZ+IBP). S. maltophilia biofilms became more resistant to removal by NaOCl when developed in the presence of mixtures of CA+CBZ and CA+CBZ+IBP. Also, biofilm production was significantly affected. CA was present in all the combinations that altered biofilm behaviour. The overall results propose that exposure to ECs for 26days had not a huge impact on S. maltophilia planktonic antimicrobial susceptibility. Nevertheless, the prolonged exposure to some ECs altered biofilm production and tolerance to NaOCl, with a potential practical outcome of hindering DWDS disinfection. The simultaneous presence of different ECs in the environment may amplify biofilm resilience.This work was the result of the projects: POCI-01-0145-FEDER-030219; POCI-01-0145-FEDER-006939 (Laboratory for Process Engineering, Environment, Biotechnology and Energy – UID/EQU/00511/2013) funded by the European Regional Development Fund (ERDF), through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI) and by national funds, through FCT - Fundação para a Ciência e a Tecnologia. NORTE-01-0145-FEDER-000005 – LEPABE-2-ECO-INNOVATION, supported by North Portugal Regional Operational Program (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). Grants attributed by Portuguese Foundation for Science and Technology – FCT – to Inês Gomes (SFRH/BD/103810/2014) and Lúcia Simões (SFRH/BPD/81982/2011).info:eu-repo/semantics/publishedVersio

Influence of different copper materials on biofilm control using chlorine and mechanical stress

The selection of materials for plumbing application has potential implications on the chemical and microbiological quality of the delivered water. This work aims to evaluate the action of materials with different copper content (0, 57, 96 and 100%) on biofilm formation and control by chlorination and mechanical stress. A strain of Stenotrophomonas maltophilia isolated from drinking water was used as model microorganism and biofilms were developed in a rotating cylinder reactor (RCR) using realism-based shear stress conditions. Biofilms were characterized phenotypically and exposed to three control strategies: 10 mg/l of free chlorine for 10 min; an increased shear stress (equivalent to 1.5 m/s of fluid velocity); and the combination of both treatments. Biofilms formed on the copper materials had lower wet mass and produced significantly lower amounts of extracellular proteins than those formed on stainless steel (0% of copper content). Although, the effects of copper materials on biofilm cell density was not significant, these materials had important impact on the efficacy of chemical and/or mechanical treatments. Biofilms formed on 96 or 100% copper materials had lower content of culturable bacteria than that observed on stainless steel after exposure to chlorine or shear stress. The mechanical treatment used had no relevant effects in biofilm control. The combination of chemical and mechanical treatments only caused higher culturability reduction than chlorine in biofilms formed on 57% copper alloy. The number of viable cells present in bulk water after biofilm treatment with chlorine was lower when biofilms were formed on any of the copper surface. The overall results are of potential importance on the selection of materials for drinking water distribution systems, particularly for house and hospital plumbing systems to overcome the effects from chlorine decay. Copper alloys may have a positive public health impact by reducing the number of viable cells in the delivered water after chlorine exposure and improving the disinfection of DW systems. Moreover, the results demonstrate that residual chlorine and mechanical stress, two strategies conventionally used for disinfection of drinking water distribution systems, failed in S. maltophilia biofilm control.This work was the result of the projects: UIDB/00511/2020 of the Laboratory for ProcessEngineering, Environment, Biotechnology and Energy – LEPABE - funded by national funds throughthe FCT/MCTES(PIDDAC); PTDC/BII-BTI/30219/2017-POCI-01-0145-FEDER-030219;POCI-01-0145-FEDER-006939, funded by FEDER funds through COMPETE2020 – ProgramaOperacional Competitividade e Internacionalização (POCI) and by national funds (PIDDAC) throughFCT/MCTES; NORTE-01-0145-FEDER-000005 – LEPABE-2-ECO-INNOVATION, supported by NortePortugal Regional Operational Programme (NORTE 2020), under PORTUGAL 2020 PartnershipAgreement, through the European Regional Development Fund (ERDF)info:eu-repo/semantics/publishedVersio

Copper surfaces in biofilm control

Biofilms are structures comprising microorganisms associated to surfaces and enclosed by an extracellular polymeric matrix produced by the colonizer cells. These structures protect microorganisms from adverse environmental conditions. Biofilms are typically associated with several negative impacts for health and industries and no effective strategy for their complete control/eradication has been identified so far. The antimicrobial properties of copper are well recognized among the scientific community, which increased their interest for the use of these materials in different applications. In this review the use of different copper materials (copper, copper alloys, nanoparticles and copper-based coatings) in medical settings, industrial equipment and plumbing systems will be discussed considering their potential to prevent and control biofilm formation. Particular attention is given to the mode of action of copper materials. The putative impact of copper materials in the health and/or products quality is reviewed taking into account their main use and the possible effects on the spread of antimicrobial resistance.This work was financially supported by: Base Funding—UIDB/00511/2020 of LEPABE and UIDB/00081/2020 of CIQUP funded by national funds through the FCT/MCTES (PIDDAC); Project Biocide_for_Biofilm—PTDC/BII-BTI/30219/2017—POCI-01-0145-FEDER-030219, ABFISH—PTDC/ASP-PES/28397/2017—POCI-01-0145-FEDER-028397 and ALGAVALOR—POCI-01-0247-FEDER-035234, funded by FEDER funds through COMPETE2020—Programa Operacional Competitividade e Internacionalização (POCI) and by national funds (PIDDAC) through FCT/MCTES; Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020—Programa Operacional Regional do Norte; SFRH/BSAB/150379/2019 (Manuel Simões).info:eu-repo/semantics/publishedVersio

Emerging contaminants affect the microbiome of water systems: strategies for their mitigation

The presence of emerging contaminants (ECs) in the environment has been consistently recognized as a worldwide concern. ECs may be defined as chemicals or materials found in the environment at trace concentrations with potential, perceived, or real risk to the One Health trilogy (environment, human, and animal health). The main concern regarding pharmaceuticals and in particular antibiotics is the widespread dissemination of antimicrobial resistance. Nevertheless, non-antimicrobials also interact with microorganisms in both bulk phase and in biofilms. In fact, drugs not developed for antimicrobial chemotherapy can exert an antimicrobial action and, therefore, a selective pressure on microorganisms. This review aims to provide answers to questions typically ignored in epidemiological and environmental monitoring studies with a focus on water systems, particularly drinking water (DW): Do ECs exposure changes the behavior of environmental microorganisms? May non-antibiotic ECs affect tolerance to antimicrobials? Do ECs interfere with biofilm function? Are ECs-induced changes in microbial behavior of public health concern? Nowadays, the answers to these questions are still very limited. However, this study demonstrates that some ECs have significant effects in microbial behavior. The most studied ECs are pharmaceuticals, particularly antibiotics, carbamazepine and diclofenac. The pressure caused by antibiotic and other antimicrobial agents on the acquisition and spread of antibiotic resistance seems to be unquestionable. However, regarding the effects of ECs on the development and behavior of biofilms, the conclusions of different studies are still controversial. The dissimilar findings propose that standardized tests are needed for an accurate assessment on the effects of ECs in the microbiome of water systems. The variability of experimental conditions, combined with the presence of mixtures of ECs as well as the lack of information about the effects of non-pharmaceutical ECs constitute the main challenge to be overcome in order to improve ECs prioritization.This work was financially supported by project UIDB/EQU/00511/2020—Laboratory for Process Engineering, Environment, Biotechnology and Energy—LEPABE funded by national funds through FCT/MCTES (PIDDAC); Projects PTDC/BII-BTI/30219/2017–POCI- 01-0145-FEDER-030219, PTDC/ASP-PES/28397/2017–POCI-01-0145-FEDER-028397 and POCI-01-0247-FEDER-035234 funded by FEDER funds through COMPETE2020— Programa Operacional Competitividade e Internacionalização (POCI) and by national funds (PIDDAC) through FCT/MCTES.info:eu-repo/semantics/publishedVersio

Overview on the hydrodynamic conditions found in industrial systems and its impact in (bio)fouling formation

Supplementary data to this article can be found online at https://doi.org/10.1016/j.cej.2021.129348.Biofouling is the unwanted accumulation of deposits on surfaces, composed by organic and inorganic particles and (micro)organisms. Its occurrence in industrial equipment is responsible for several drawbacks related to operation and maintenance costs, reduction of process safety and product quality, and putative outbreaks of pathogens. The understanding on the role of operating conditions in biofouling development highlights the hydrodynamic conditions as key parameter. In general, (bio)fouling occurs in a higher extension when laminar flow conditions are used. However, the characteristics and resilience of biofouling are highly dependent on the hydrodynamic conditions under which it is developed, with turbulent conditions being associated to recalcitrant biodeposits. In industrial settings like heat exchangers, fluid distribution networks and stirred tanks, hydrodynamics play a dual function, affecting the process effectiveness while favouring biofouling formation. This review summarizes the hydrodynamics played in conventional industrial settings and provides an overview on the relevance of hydrodynamic conditions in biofouling development as well as in the effectiveness of industrial processes.This work was financially supported by: Base Funding - UIDB/00511/2020 of LEPABE and UIDB/00081/2020 of CIQUP funded by national funds through the FCT/MCTES (PIDDAC); Project Bio cide_for_Biofilm - PTDC/BII-BTI/30219/2017 - POCI-01-0145-FEDER 030219, ABFISH – PTDC/ASP-PES/28397/2017 - POCI-01-0145- FEDER-028397 and ALGAVALOR - POCI-01-0247-FEDER-035234, fun ded by FEDER funds through COMPETE2020 – Programa Operacional Competitividade e Internacionalizaçao ˜ (POCI) and by national funds (PIDDAC) through FCT/MCTES; Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER 000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte; FCT/ SFRH/BD/147276/2019 (Susana Fernandes) and SFRH/BSAB/150379/2019 (Manuel Simoes).info:eu-repo/semantics/publishedVersio

Effect of sodium hypochlorite on bacteria isolated from drinking water

Biofilm formation inside drinking water distribution systems (DWDS) constitutes one of the major microbial problems in the distribution of safe water. Biofilms in DWDS can act as a reservoir of pathogenic microorganisms and consequently constitute a threat to public health. Therefore, the control of biofilm development inside the pipes of DWDS is a concern for drinking water companies being the use of chlorine one of the most commonly used disinfecting strategies to avoid microbial growth. The aim of this work was to understand the effects of sodium hypochlorite (NaOCl) at residual and high doses against biofilms formed by two bacteria isolated from a DWDS (Acinectobacter calcoaceticus and Stenotrophomonas maltophilia, two emergent pathogens) on polyvinyl chloride. The NaOCl effects were evaluated in bacterial membrane properties and in biofilm cohesion. NaOCl demonstrated action on the bacterial membrane, particularly on the surface hydrophobicity of A. calcoaceticus and on the surface charge of S. maltophilia. NaOCl also caused motility inhibition of A. calcoaceticus. The use of residual concentrations to control bacterial adhesion was inefficient. High concentrations were able to reduce significantly the number of adhered bacteria. However, mature biofilms formed by A. calcoaceticus and S. maltophilia were highly resistant to the combination of chemical and mechanical stresses. In conclusion, the overall results demonstrated a significant action of NaOCl on A. calcoaceticus and S. maltophilia planktonic cells and monolayer adhered cells. However, their mature biofilms were not controlled even when high biocide doses and mechanical stress were applied alone and in combination

Synthesis of platinum (II) N-heterocyclic carbenes based on adenosine

Funding Information: This research was funded by national funds through FCT?Funda??o para a Ci?ncia e a Tecnologia, I.P., Project MOSTMICRO-ITQB (refs. UIDB/04612/2020 and UIDP/04612/2020), and IF/00109/2014/CP1244/CT0007. This work was also supported by FCT fellowships number PD/BD/135483/2018 (M.I.P.S.L.) and SFRH/BD/1444412019 (G.F.). Clara S. B. Gomes acknowledges the Associate Laboratory for Green Chemistry?LAQV and the Applied Molecular Biosciences Unit?UCIBIO, which are financed by national funds from Funda??o para a Ci?ncia e a Tecnologia (UIDB/50006/2020, UIDP/50006/2020, UIDB/04378/2020, UIDP/04378/2020, respectively).The NMR spectra were acquired at CERMAX?ITQB, integrated in the National NMR Network and are partially supported by Infrastructure Project No. 022161 (co-financed by FEDER through COMPETE 2020, POCI, PORL and FCT through PIDDAC). Mass spectroscopy measurements were obtained by the UniMass Laboratory at ITQB-NOVA, Portugal. Clara S. B. Gomes acknowledges the XTAL?Macromolecular Crystallography group for granting access to the X-ray diffractometer. X-ray infrastructure financed by FCT-MCTES through project RECI/BBB-BEP/0124/2012. Funding Information: Funding: This research was funded by national funds through FCT—Fundação para a Ciência e a Tecnologia, I.P., Project MOSTMICRO-ITQB (refs. UIDB/04612/2020 and UIDP/04612/2020), and IF/00109/2014/CP1244/CT0007. This work was also supported by FCT fellowships number PD/BD/135483/2018 (M.I.P.S.L.) and SFRH/BD/1444412019 (G.F.). Clara S. B. Gomes acknowledges the Associate Laboratory for Green Chemistry—LAQV and the Applied Molecular Biosciences Unit—UCIBIO, which are financed by national funds from Fundação para a Ciência e a Tecnologia (UIDB/50006/2020, UIDP/50006/2020, UIDB/04378/2020, UIDP/04378/2020, respectively). Funding Information: Acknowledgments: The NMR spectra were acquired at CERMAX—ITQB, integrated in the National NMR Network and are partially supported by Infrastructure Project No. 022161 (co-financed by FEDER through COMPETE 2020, POCI, PORL and FCT through PIDDAC). Mass spectroscopy measurements were obtained by the UniMass Laboratory at ITQB-NOVA, Portugal. Clara S. B. Gomes acknowledges the XTAL—Macromolecular Crystallography group for granting access to the X-ray diffractometer. X-ray infrastructure financed by FCT-MCTES through project RECI/BBB-BEP/0124/2012. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Organometallic derivatization of nucleosides is a highly promising strategy for the im-provement of the therapeutic profile of nucleosides. Herein, a methodology for the synthesis of metalated adenosine with a deprotected ribose moiety is described. Platinum (II) N-heterocyclic carbene complexes based on adenosine were synthesized, namely N-heterocyclic carbenes bearing a protected and unprotected ribose ring. Reaction of the 8-bromo-2′,3′,5′-tri-O-acetyladenosine with Pt (PPh3)4 by C8−Br oxidative addition yielded complex 1, with a PtII centre bonded to C-8 and an unprotonated N7. Complex 1 reacted at N7 with HBF4 or methyl iodide, yielding protic carbene 2 or methyl carbene 3, respectively. Deprotection of 1 to yield 4 was achieved with NH4OH. Deprotected compound 4 reacted at N7 with HCl solutions to yield protic NHC 5 or with methyl iodide yielding methyl carbene 6. Protic N-heterocyclic carbene 5 is not stable in DMSO solutions leading to the formation of compound 7, in which a bromide was replaced by chloride. The cis-influence of complexes 1–7 was examined by31P{1H} and195Pt NMR. Complexes 2, 3, 5, 6 and 7 induce a decrease of1 JPt,P of more than 300 Hz, as result of the higher cis-influence of the N-heterocyclic carbene when compared to the azolato ligand in 1 and 4.publishersversionpublishe

Drinking-water isolated Delftia acidovorans selectively coaggregates with partner bacteria and facilitates multispecies biofilm development

Coaggregation plays an important role in the development of multispecies biofilms in different environments, often serving as an active bridge between biofilm members and other organisms that, in their absence, would not integrate the sessile structure. The ability of bacteria to coaggregate has been reported for a limited number of species and strains. In this study, 38 bacterial strains isolated from drinking water (DW) were investigated for their ability to coaggregate, in a total of 115 pairs of combinations. Among these isolates, only Delftia acidovorans (strain 005P) showed coaggregating ability. Coaggregation inhibition studies have shown that the interactions mediating D. acidovorans 005P coaggregation were both polysaccharide-protein and protein-protein, depending on the interacting partner bacteria. Dual-species biofilms of D. acidovorans 005P and other DW bacteria were developed to understand the role of coaggregation on biofilm formation. Biofilm formation by Citrobacter freundii and Pseudomonas putida strains highly benefited from the presence of D. acidovorans 005P, apparently due to the production of extracellular molecules/public goods favouring microbial cooperation. This was the first time that the coaggregation capacity of D. acidovorans was demonstrated, highlighting its role in providing a metabolic opportunity for partner bacteria.This work was financially supported by LA/P/0045/2020 (ALiCE), UIDB/00511/2020 and UIDP/00511/2020 (LEPABE), funded by national funds through FCT/MCTES (PIDDAC); UIDB/04469/2020 (CEB) and by LABBELS – Associate Laboratory in Biotechnology, Bioengineering and Microelectromechnaical Systems, LA/P/0029/2020; UIDB/04033/2020 (CITAB); Project Biocide_for_Biofilm-PTDC/BII-BTI/30219/2017-POCI-01-0145-FEDER-030219, ABFISH–PTDC/ASP-PES/28397/2017-POCI-01-0145-FEDER- 028397 and Germirrad-POCI-01-0247-FEDER-072237, funded by FEDER funds through COMPETE2020–Programa Operacional Competitividade e Internacionalização (POCI) and by national funds (PIDDAC) through FCT/MCTES; project HealthyWaters (NORTE-01-0145-FEDER-000069)- NORTE 2020/ERDF; and the FCT grant (2020.04773.BD).info:eu-repo/semantics/publishedVersio

The effects of chemical and mechanical stresses on Bacillus cereus and Pseudomonas fluorescens single- and dual-species biofilm removal

Biofilm control is mainly based on chemical disinfection, without a clear understanding of the role of the biocides and process conditions on biofilm removal. This study aims to understand the effects of a biocide (benzyldimethyldodecyl ammonium chlorideBDMDAC) and mechanical treatment (an increase of shear stress -w) on single- and dual-species biofilms formed by Bacillus cereus and Pseudomonas fluorescens on high-density polyethene (HDPE). BDMDAC effects were initially assessed on bacterial physicochemical properties and initial adhesion ability. Then, mature biofilms were formed on a rotating cylinder reactor (RCR) for 7 days to assess the effects of chemical and mechanical treatments, and the combination of both on biofilm removal. The results demonstrated that the initial adhesion does not predict the formation of mature biofilms. It was observed that the dual-species biofilms were the most susceptible to BDMDAC exposure. The exposure to increasing w emphasised the mechanical stability of biofilms, as lower values of w (1.66 Pa) caused high biofilm erosion and higher w values (17.7 Pa) seem to compress the remaining biofilm. In general, the combination of BDMDAC and the mechanical treatment was synergic in increasing biofilm removal. However, these were insufficient to cause total biofilm removal (100%; an average standard deviation of 11% for the method accuracy should be considered) from HDPE.This work was financially supported by: Base Funding—UIDB/00511/2020 of LEP-ABE funded by national funds through the FCT/MCTES (PIDDAC); Project Biocide_for_Biofilm—TDC/BII-BTI/30219/2017—POCI-01-0145-FEDER-030219; Germirrad—POCI-01-0247-FEDER-072237; pBio4.0—POCI-01-0247-FEDER-033298, funded by FEDER funds through COMPETE2020—Programa Operacional Competitividade e Internacionalização (POCI) and by national funds (PIDDAC) through FCT/MCTES. 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 BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020—Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio