Biofilms最新文献

{"title":"Novel photobioreactor for moving bed biofilm cultivation of terrestrial cyanobacteria","authors":"J. Walther, N. Erdmann, Katharina Wastian, D. Strieth, R. Ulber","doi":"10.5194/biofilms9-28","DOIUrl":"https://doi.org/10.5194/biofilms9-28","url":null,"abstract":"<div>\u0000<p>Terrestrial cyanobacteria grow quite poorly as suspension culture. This is one of the reasons why they have not yet been considered as producers of interesting metabolites such as antibacterial substances. Previous work in our group have shown that surface-associated growth can significantly increase productivity [1]. Moving bed bioreactor technology, which is already established in wastewater treatment, offers a possibility to carry out such growth on a larger scale. In these reactors, the bacteria grow on the surface of solid structured carrier particles in areas protected from mechanical abrasion (protected surface). These particles are usually about 1-5 cm in size and are made of high-density polyethylene (HDPE). Moving bed processes for microalgae have only been described for fabric as a solid substrate [2] whereby only 30% of the biomass was actually immobilized on the carrier particles. For this reason, different HDPE carrier particles and different cyanobacteria were investigated. Three different cyanobacteria could be successfully cultivated on two different particles in a 1.5-liter photobioreactor in a moving bed. As an up-scale step, a larger reactor was developed, which provided a larger cultivation surface in combination with a sufficient illumination.</p>\u0000<p><strong>Photobioreactor</strong></p>\u0000<p>The design of the reactor is similar to Zhuang et al. [2]. Based on an 80x35x40&#160;cm tank, the reactor has a working volume of 65&#160;liters. At a particle filling degree of 27&#160;%, the reactor has a protected cultivation surface area of 11.26&#160;m&#178; within the particles. This corresponds to 173&#160;m&#178; per m&#179; reactor volume. Their circulation is generated by a gassing unit on the ground. An inclined plate is installed beside the gassing unit, to avoid a flow dead zone at the bottom of the reactor. The reactor is illuminated by LEDs located outside the reactor. The growth is monitored offline by the determination of the dry biomass (bdm) and the measurement of the biofilm thickness by optical coherence tomography (OCT).</p>\u0000<p><strong>Results</strong></p>\u0000<p>Cultivations with the cyanobacterium Trichocoleus sociatus were carried out. The inoculum was added to the reactor as suspended biomass with a concentration of 0.035 g_bdm/L. After two weeks, the complete biomass was immobilized as a thin biofilm on the carrier particles. Between day 18 and day 45, an increase in the median biofilm thickness from 36 &#181;m to 65 &#181;m could be measured with an increase of the dry biomass from 0.44 to 1.56 g/L. This volume-specific yield is similar to cultivations in the 1.5-liter photobioreactors with carrier particles.</p>\u0000<p>&#160;</p>\u0000<p><strong>Funding</strong></p>\u0000<p>The project is financially supported by the DFG (Project number UL 170/16-1) and the Ministry of Education of Rhineland-Palatinate (bm.rlp) (iProcess intelligent process development &#8211; from modelling to product)</p>\u0000<p>&#160;</p>\u0000<p><s","PeriodicalId":87392,"journal":{"name":"Biofilms","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41863728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic and spatially resolved mid-infrared characterization of biofilms","authors":"E. Leiss-Holzinger, Robert Zimmerleiter, Eva Wagner, K. Rychli, M. Brandstetter","doi":"10.5194/biofilms9-92","DOIUrl":"https://doi.org/10.5194/biofilms9-92","url":null,"abstract":"Elisabeth Leiss-Holzinger, Robert Zimmerleiter, Eva Maria Wagner, Kathrin Rychli, and Markus Brandstetter Research Center for non-destructive Testing, Infrared & Raman Spectroscopy, Austria (elisabeth.leiss@recendt.at) FFoQSI GmbH – Austrian Competence Centre for Feed and Food Quality, Safety and Innovation, Tulln, Austria Institute for Food Safety, Food Technology and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria","PeriodicalId":87392,"journal":{"name":"Biofilms","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41962797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Iron as a biofilm control agent: manipulation of biofilm development and differentiation","authors":"L. Gierl, H. Horn, M. Wagner","doi":"10.5194/biofilms9-75","DOIUrl":"https://doi.org/10.5194/biofilms9-75","url":null,"abstract":"In order to optimize operative parameters in wastewater treatment plants, drip irrigation systems as well as in biofilm reactors, it is necessary to understand biofilm development and proliferation under certain conditions. Additionally, the physical structure of biofilms is of great interest since it determines the interaction with its microenvironment, while knowledge about the mechanical behavior of biofilms is important for applying e.g., cleaning procedures.","PeriodicalId":87392,"journal":{"name":"Biofilms","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48128128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of mesoporous silica nanoparticles-based nanoantibiotics and capsaicin on E. coli and S. aureus biofilms","authors":"A. Slita, Prakirth Govardhanam, I. Opstad, D. Karaman, J. Rosenholm","doi":"10.5194/biofilms9-133","DOIUrl":"https://doi.org/10.5194/biofilms9-133","url":null,"abstract":"<p><strong>Introduction</strong></p>\u0000<p>Since antibiotics were discovered, bacteria have demonstrated the ability to develop resistance by many different mechanisms. According to WHO reports from 2014, there has been an alarming increase in the antibiotic resistant bacterial strains in most parts of the world¹. Our previous results showed that a nanoantibiotic (NAB) design created in our laboratory², composed of a cerium oxide core, mesoporous silica shell loaded with capsaicin, and a chitosan coating, are effective against planktonic E. coli. However, most of the pathogenic bacteria form biofilms during infections. That is why the next stage of studying NAB is to determine whether they are effective against biofilms of different species. Moreover, the results of NAB efficiency against planktonic E. coli did not clearly show the contribution of the antibiotic drug component of NAB &#8211; capsaicin. Hence, the first step of the current study is to determine whether and to what degree, mesoporous silica nanoparticles (MSN) &#8211; serving as NAB model in this case - penetrate biofilms as a function of particle shape and surface coating; as well as finding the efficient concentration of capsaicin against E. coli and S. aureus &#160;to optimize the NAB dosing against biofilms.</p>\u0000<p><strong>&#160;</strong></p>\u0000<p><strong>Aim</strong></p>\u0000<p>To check in vitro penetration of MSN on S. aureus biofilm and antibacterial activity of NAB and pure capsaicin on E. coli and S. aureus biofilms.</p>\u0000<p><strong><br />Methods</strong></p>\u0000<p>To investigate NAB efficiency on biofilms MBEC-high-throughput assay³ was performed. Equal biofilms formed on peg-lids were incubated with different concentrations of NAB and capsaicin. After different time point biofilms were sonicated and plated on agar plated to perform CFU counting. To determine the efficient concentration of capsaicin, biofilms were formed in 12 well plates and then incubated with different concentrations of capsaicin. To visualize inhibitory effect, plating for CFU counting and Resazurin assay were applied. To evaluate the penetration of particles, labeled and non-labeled particles were added to fully grown St. aureus biofilms, incubated and visualized with confocal microscopy and structured illumination microscopy.</p>\u0000<p><strong>&#160;</strong></p>\u0000<p><strong>Results</strong></p>\u0000<ol>\u0000<li>Through two different microscopy techniques penetration of particles into biofilm and their localization next to bacteria cells were observed.</li>\u0000<li>In MBEC-high-throughput assay no inhibitory effect of NAB against E. coli biofilms was detected in comparison with untreated bacteria.</li>\u0000<li>Resazurin assay and CFU counting method allowed us to determine the most efficient concentration of capsaicin against E. coli and St. aureus biofilms.</li>\u0000</ol>\u0000<p><strong>&#160;</strong></p>\u0000<p><strong>Conclusion</strong></p>\u0000<ol>\u0000<li>Use of MSN and NAB in particular to deliver active antiba","PeriodicalId":87392,"journal":{"name":"Biofilms","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45170541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of different copper materials on biofilm control using chlorine and mechanical stress","authors":"I. Gomes, L. Simões, M. Simões","doi":"10.5194/biofilms9-123","DOIUrl":"https://doi.org/10.5194/biofilms9-123","url":null,"abstract":"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.","PeriodicalId":87392,"journal":{"name":"Biofilms","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43579356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heterogeneities in biofilms from clinical isolates under flow conditions","authors":"C. Cardenas, R. Rusconi","doi":"10.5194/biofilms9-113","DOIUrl":"https://doi.org/10.5194/biofilms9-113","url":null,"abstract":"Pancreatic cancer is the fourth leading cause of cancer death worldwide. The most common sign of presentation of pancreatic cancer is obstructive jaundice, which prevents the drainage of bile into the intestines and it is often associated with decreased survival in patients. Nowadays more than 70% of the patients with biliary obstructive jaundice is treated by biliary stenting; however, biliary stenting disrupts the natural anatomic barrier between the biliary and the gastrointestinal tract, strongly increasing the risk of a bacterial infection. Moreover, duodenal bacteria, by gaining access into the biliary system, can adhere to the stent surface and develop biofilms. Nevertheless, very little is known about the growth of biofilms on the stents and their role in infectious post-operative complications. In particular, the biliary system is an inherently fluid mechanical environment, where the gallbladder provides the driving pressure and the flow rate of the bile going through the ducts depends on the resistance between the gallbladder and the downstream end of the common bile duct. The average flow rate of the bile ranges between approximately 0.5 to 5 ml/min, which depends if the body is fasting or after a meal; this flow rate then corresponds – in the case for example of plastic stents, which are typically 2-4 mm in luminal diameter – to a maximum flow velocity of about 1-40 mm/s and to a shear rate at the inner surface of the stent of 1-80 s. Therefore, the mechanical stress induced by the bile flow in the stent is likely to play a significant role in the formation of biofilms, as shown by our data. Six clinically relevant isolates from preoperative biliary stents were selected to be grown inside microfluidic channels at different flow rates, in which bacterial attachment and biofilm dynamics were recorded and quantified. We found that fluid flow largely influences biofilm morphology in all the isolates, for which the conditions of flow and shear stress that trigger heterogeneities in biofilm structure have been determined. These results will help us to improve our understanding of biofilm formation in the presence of fluid dynamic environments and eventually consider optimal parameters of flow in the design of medical devices.","PeriodicalId":87392,"journal":{"name":"Biofilms","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41692434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of the ability to form biofilms of microorganisms isolated from the milk industry in Canada","authors":"C. Goetz, Nissa Niboucha, J. Jean","doi":"10.5194/biofilms9-134","DOIUrl":"https://doi.org/10.5194/biofilms9-134","url":null,"abstract":"The ability of microorganisms to form biofilms has become a major problem in the dairy industry in Canada, notably by affecting the quality and the safety of the by-products. Established biofilms are difficult to remove during the CIP cleaning system and may become resistant to sanitizers. Therefore, it is important to identify and characterize the microorganisms associated to biofilm in the Canadian dairy industry, allowing to develop improvement strategies of biofilm control. The purpose of this study is to evaluate the ability to form biofilms by spoilage microorganisms isolated in processing plants in Canada. For this purpose, 19 strains were isolated from problems associated with the formation of biofilms in the dairy industry and identified using a MALDI-TOF mass spectrometer. The single species biofilm production of these isolates was then measured after a crystal violet coloration using 96-well microplates. The results revealed different biofilm formation profiles depending of the isolates in culture medium. Indeed, 7/19 isolates are moderate or strong biofilm producers and 12/19 isolates are negative or weak biofilm producers. Furthermore, enzymatic treatments revealed that the composition of the biofilms was different depending of the species but also the isolates. In conclusion, the results suggest that some of the isolates collected in the dairy industry have the ability to produce moderate or strong biofilms and thus, to facilitate the persistence of other spoilage microorganisms but also potential pathogenic microorganisms such as Listeria monocytogenes. The characterization of those biofilms will be helpful to the development of an effective approach allowing a better control of the biofilms in the dairy industry.","PeriodicalId":87392,"journal":{"name":"Biofilms","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47466713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Blocking Vibrio cholerae-mediated hemagglutination with short peptide antagonists","authors":"Shuaiqi Guo, Cameron J. Lloyd, B. Kinrade, Mustafa Sherik, I. Voets, K. Klose, P. Davies","doi":"10.5194/biofilms9-121","DOIUrl":"https://doi.org/10.5194/biofilms9-121","url":null,"abstract":"<p>Many bacteria use repeats-in-toxin (RTX) adhesins to mediate binding to host cells and facilitate subsequent colonisation and infection by forming biofilms. Vibrio cholerae, the causative agent of cholera, uses a 230-kDa RTX adhesin, FrhA, to facilitate intestinal colonization. FrhA also mediates hemagglutination of red-blood cells (erythrocytes). Here we have demonstrated that the hemagglutination capability of FrhA is localized to a ~ 20-kDa domain near its C terminus. Bioinformatic analyses indicated this erythrocyte-binding domain (VcEBD) is 65% identical to a peptide-binding module found in the 1.5-MDa ice-binding RTX adhesin that helps its Antarctic bacterium, Marinomonas primoryensis, form symbiotic biofilms with diatoms on the underside of sea ice. This suggested that the FrhA binds V. cholerae to proteins present on the cell surface of erythrocytes. X-ray crystallography revealed that VcEBD has an oblong &#946;-sandwich fold with a shallow, Ca²⁺-dependent ligand-binding cavity that can anchor a peptidyl ligand with a free terminal carboxyl group. Using a structure-guided approach, we screened a small library of ~ 60 short peptides and optimized the affinity of VcEBD&#8217;s peptidyl ligands by roughly 1,000-fold. Importantly, the high-affinity ligands are effective at blocking V. cholerae from binding to erythrocytes at nano-molar concentrations. Structures of VcEBD in complex with three different peptides further elucidated the molecular basis for their interactions, which sets the stage for the development of ligand-based antagonists that may help disrupt V. cholerae interaction with intestinal cells to prevent or treat cholera. With the spread of antibiotic-resistant pathogenic bacteria, this work sheds light on an anti-adhesion approach for combating bacterial infections without the excessive use of antibiotics.</p>","PeriodicalId":87392,"journal":{"name":"Biofilms","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46920311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Power output enhancement in ceramic, mL-scale Microbial Fuel Cell","authors":"I. Gajda, Buddhi Arjuna Mendis, J. Greenman, I. Ieropoulos","doi":"10.5194/biofilms9-159","DOIUrl":"https://doi.org/10.5194/biofilms9-159","url":null,"abstract":"<p>A microbial fuel cell (MFC) is a renewable energy converter, which transforms organic biomass directly into electricity, using biofilm-electrode metabolic interaction within a bioelectrochemical cell. Efficiency of this transformation can be enhanced through miniaturisation. Miniaturisation of MFCs offers higher surface-area-to-volume ratio and improved mass transfer.</p>\u0000<p>The development of mL-scale; power dense and low cost MFCs, are of great interest in diverse areas of research, ranging from modern bio-robotics, internet-of-things devices, electrical energy generation, remote sensing to wastewater treatment and mineral recovery. The biofilms increased ability in converting organic pollutants into electric power more efficiently, makes mL-sized MFCs attractive for the development of multi-modular stacks and usable off-grid power sources with an ability of enhanced wastewater treatment. This work focuses on small scale MFCs; i) minimising the distance between feeding stream and the biofilm, ii) construction and analysis of a &#160;millilitre scale prototype, using a low cost ceramic separator for higher energy recovery efficiency and sensitivity enhancement to substrates and pollutants. The study aims to test efficient cathode modifications, using graphene ink and magnetite (Fe₃O₄); in order to improve the oxygen reduction reaction (ORR). This in turn is envisioned in an increase of the output, reaching comparable power levels to the larger MFC prototypes tested so far. The additives are chosen such that, &#160;both graphene and iron&#8211;based oxides are known from the literature to be catalysts for electrochemical processes, this work focusses on their incorporation into the open-to air cathode in novel, low cost MFC bioreactors.</p>\u0000<p>The miniaturised MFC construction constituted of an in-house fabricated small scale ceramic cylinder of internal volume of 3.88 mL. An anode, made of carbon veil fibre with a coating of activated carbon powder, was placed inside the ceramic cylinder, while the cathode was attached to the outer surface of the structure. Three types of cathodes were tested: i) activated carbon as the control (AC), ii) AC with a graphene ink coating (AC+G) and iii) AC with graphene ink and magnetite powder blend (AC+G+M). Experiments were conducted in triplicate using activated sludge and urine inoculum and thereafter continuously supplemented with 100% real human urine. The results show that the control produced up to 0.85 mW (219 W/m³), while AC+G produced 1.22 mW (312 W/m³), and AC+G+M 1.12 (288 W/m³) which is a 44 % and a 32 % increase respectively in comparison to the control. Comparison of linear sweep voltammetry (LSV) showed superior performance of both modified electrodes against the unmodified AC cathode; further resulting in an enhancement of ORR reaction rate. Power outputs from this work show over 14 times improvement in power density levels in comparison t","PeriodicalId":87392,"journal":{"name":"Biofilms","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49138848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wetting properties of biofilm-coated surfaces produced at controlled shear flow conditions","authors":"Federica Recupido, M. Petala, M. Kostoglou, S. Caserta, S. Guido, T. Karapantsios","doi":"10.5194/biofilms9-140","DOIUrl":"https://doi.org/10.5194/biofilms9-140","url":null,"abstract":"<p>Biofilms prevention and removal are crucial in many industrial and medical applications. Their complex and cohesive structure provides resistance to cleaning even to strong disinfectants. A key factor for their behavior is the wetting properties of their surfaces.</p>\u0000<p>The main goal of this work is to study the wetting properties of biofilms produced by bacteria <em>Pseudomonas fluorescens</em>. Biofilms are obtained on glass coupons under well controlled flow conditions, using custom-made flow cell devices. Different nutrient concentration and shear flow conditions are investigated.</p>\u0000<p>Biofilm wetting properties are examined under imposed external body forces (forced wetting) through a specialized device, named Kerberos&#174;. Kerberos&#174; is capable of subjecting sessile droplets to varying tilting angles and centrifugal forces while monitoring the variation of the droplet shape in X, Y and Z-directions through three Wi-Fi cameras. Wetting experiments are carried out using water-based solution (dye solution) droplets on biofilm-coated glass coupons. In this work, spreading/sliding behaviour of droplets are investigated only on horizontal substrates (no tilting) under the action of centrifugal forces. Apart from wetting properties, biofilm growth kinetics and surface morphology at different nutrient and shear flow conditions are also assessed.</p>\u0000<p>Results show that, according to the different growth conditions, biofilms present different wetting properties. At lower nutrient concentration and shear flow conditions, spreading and sliding behaviour are similar to that observed in glass coupons in the absence of biofilm. At higher nutrient and shear flow conditions, spontaneous wicking of the biofilm occurs the moment of droplet deposition on the biofilm leading to irregular and jagged shapes of droplets, while on the contrary water droplets look like smooth spherical sections on pure glass. The spontaneous wicking affects the droplet initial shape and so the wetting behaviour during the subsequent rotation tests. In each examined condition, biofilms show hydrophilic properties.</p>\u0000<p>&#160;</p>","PeriodicalId":87392,"journal":{"name":"Biofilms","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49064363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}