Biofilms最新文献

{"title":"Surface-associated plant cell culture","authors":"A. Mehring, J. Stiefelmaier, R. Ulber","doi":"10.5194/biofilms9-79","DOIUrl":"https://doi.org/10.5194/biofilms9-79","url":null,"abstract":"<p>Biofilms are typically characterized as a consortium of microorganisms, which adhere to each other and often to surfaces. This adhesion is realized by extracellular polymeric substances (EPS), which are secreted by the microorganisms and mainly consist of water, polysaccharides, proteins and lipids as well as nucleic acids and lysis products [1]. Although cultured plant cells are not typically considered biofilms, parallels can be found in the properties of plant calli. These callus cells tend to form cohesive aggregates, owing to their extracellular matrix, and often strongly adhere to the agar plates they are kept on. The extracellular matrix of plant cells is mainly composed of structural polysaccharides, such as xyloglucans, arabinogalactans [2], homogalacturonan and extensins [3] among others. Cultured plant cells were found to adhere to surfaces before [4]. Surface-associated plant cell culture may have potential in a (semi&#8209;)continuous cultivation including product secretion, as was shown in principle for alginate-embedded plant cells [5]. For cyanobacterial biofilms, an efficient strategy for EPS extraction was recently developed [6]. The transferability of these protocols to biofilm-like growing plant calli of Ocimum basilicum is currently being investigated. Subsequently, the composition of the extracellular matrix extracted from cultured O.&#160;basilicum cells is of interest. Furthermore, the adhesive properties of O.&#160;basilicum suspension cultures to microstructured surfaces and the potential role of the extracellular matrix are under investigation. An investigation of culture properties in an aerosol photobioreactor [7] is planned as well.</p>\u0000<p>This project is financially supported by the German research foundation (DFG, project number SFB 926-C03).</p>\u0000<p>&#160;</p>\u0000<p>References:</p>\u0000<p>[1]&#160;&#160;&#160;&#160;&#160; H. C. Flemming, T. R. Neu, and D. J. Wozniak, &#8220;The EPS matrix: The &#8216;House of Biofilm Cells,&#8217;&#8221; J. Bacteriol., vol. 189, no. 22, pp. 7945&#8211;7947, 2007.</p>\u0000<p>[2]&#160;&#160;&#160;&#160;&#160; I. M. Sims, K. Middleton, A. G. Lane, A. J. Cairns, and A. Bacic, &#8220;Characterisation of extracellular polysaccharides from suspension cultures of members of the Poaceae,&#8221; Planta, vol. 210, no. 2, pp. 261&#8211;268, Jan. 2000.</p>\u0000<p>[3]&#160;&#160;&#160;&#160;&#160; M. Popielarska-Konieczna, K. Sala, M. Abdullah, M. Tuleja, and E. Kurczy&#324;ska, &#8220;Extracellular matrix and wall composition are diverse in the organogenic and non-organogenic calli of Actinidia arguta,&#8221; Plant Cell Rep., no. 0123456789, 2020.</p>\u0000<p>[4]&#160;&#160;&#160;&#160;&#160; R. J. Robins, D. O. Hall, D. &#8208;J Shi, R. J. Turner, and M. J. C. Rhodes, &#8220;Mucilage acts to adhere cyanobacteria and cultured plant cells to biological and inert surfaces,&#8221; FEMS Microbiol. Lett., vol. 34, no. 2, pp. 155&#8211;160, 1986.</p>\u0000<p>[5]&#160;&#160;&#160;&#160;&#160; Y. Kobayashi, H. Fukui, and M.","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":"45639529","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":"A thin line between plankton and biofilm","authors":"I. Dogša, R. Kostanjšek, D. Stopar","doi":"10.5194/biofilms9-157","DOIUrl":"https://doi.org/10.5194/biofilms9-157","url":null,"abstract":"<p>Planktonic bacterial cells are by definition not aggregated. However, our previous work, where we have demonstrated the invisible mechanical connections between bacterial cells in dilute planktonic suspensions, challenged this assumption. Here we provide an experimental evidence using autocorrelation analysis of micrographs that in planktonic suspensions of <em>B. subtilis</em> a size continuum of aggregated structures is formed. In the microbial aggregates viable cells were embedded in the nucleic acid network. The eDNA was released during regular cell lysis events. To determine the size distribution of planktonic bacterial aggregates a pair-wise spatial correlations of bacterial cells in microscopic images were calculated. The monotonously decreasing shape of the autocorrelation function indicated a continuous distribution of bacterial aggregate sizes from monomer to multimers. Soft bacterial aggregates in dilute suspensions provide a missing link in a continuum of organic matter in aqueous environments and can significantly improve our understanding how non-attached biofilms form during planktonic growth.</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":"44321338","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":"Interfacing anoxic Shewanella oneidensis biofilms with electrically conducting nanostructures","authors":"Edina Klein, René Wurst, David Rehnlund, J. Gescher","doi":"10.5194/biofilms9-139","DOIUrl":"https://doi.org/10.5194/biofilms9-139","url":null,"abstract":"<p><em>Shewanella oneidensis</em> MR1 is the best understood model organism with regards to dissimilatory metal reduction and extracellular electron transfer onto carbon electrodes in bioelectrochemical systems (BES)¹. However, under anoxic conditions <em>S. oneidensis</em> is known to form very thin biofilms resulting in low current density output. In contrast, another exoelectrogenic model organism <em>Geobacter surfurreduscens</em> can form electroactive biofilms up to 100 &#181;m in thickness. This organism is known for its ability to transport electrons over a long range (> 10 &#181;m) along a network of protein filaments, called microbial nanowires. Although still controversial, it was recently reported that OmcS has a special importance for the conductivity of these nanowires². One of the key differences between <em>G. surfurreduscens</em> and <em>S. oneidensis</em> lies in how cell-to-cell electronic communication occurs, which dictate the range of electronic communication between distant cells. <em>S. oneidensis</em> relies on direct cell-to-cell communication via electron transfer between outer membrane cytochromes or via soluble redox active flavins that are secreted by the cells³. Our research is based on the question, what if the <em>S. oneidensis</em> biofilm formation could be improved by introducing an artificial electronic network, similar to the native microbial nanowires for <em>G. sulfurreducens</em>?</p>\u0000<p>We hypothesize that synthetic biofilms containing conductive nanostructure additives would allow <em>S. oneidensis</em> to build multilayer thick biofilms under anoxic conditions on solid electron acceptors. To answer this question of how conductive materials affect the formation of anoxic <em>S. oneidensis</em> biofilms, we integrated both biological and synthetic conductive nanostructures into these biofilms. As biological additive, the <em>c</em>-type cytochrome OmcS purified from<em> G. sulfurreducens</em> was utilized. As synthetic additives, both commercially available biotinylated gold nanorods and in-house electrochemically synthesized metal nanostructures were added to anoxic <em>S.&#160;oneidensis</em> biofilms.</p>\u0000<p>Cultivation and characterization of the biofilms was performed using our newly developed microfluidic bioelectrochemical platform. Microbial cultivation with the aid of microfluidic flow chambers has a great potential to form biofilms on an easy to handle laboratory scale with simultaneously ongoing multianalytical analysis⁴. In our bioelectrochemical microfluidic, system <em>S. oneidensis</em> biofilms can be grown under anoxic conditions using an anode as sole electron acceptor. The growth behavior and bioelectrochemical performance was evaluated by a combination of electrochemical techniques (chronoamperometry, electrochemical impedance spectroscopy, cyclic voltammetry) and optical analyses (confocal laser scanning microscopy and optical coherence tomo","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":"44573306","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":"Biotechnological production of platform chemicals through anode assisted fermentation by using an artificial biofilm of S. oneidensis","authors":"Miriam Edel, J. Gescher","doi":"10.5194/biofilms9-158","DOIUrl":"https://doi.org/10.5194/biofilms9-158","url":null,"abstract":"<p>A shift from petrochemical processes to a bio-based economy is inevitable to establish a sustainable industry. Bioelectrochemical systems (BESs) are a future technology for the environment-friendly production of platform chemicals. In BESs exoelectrogenic bacteria such as <em>Shewanella oneidensis</em> can directly transfer respiratory electrons to the anode, which serves as a non-depletable electron acceptor. So far, the main limiting factor in BESs is the achievable current density which correlates to some extend with the density, thickness and metabolic activity of anode biofilms composed of exoelectrogenic microorganisms. This is especially true for<em> S.&#160;oneidensis</em> as the organism forms rather thin biofilms under anoxic conditions on anode surfaces.</p>\u0000<p>In order to enhance the organisms&#8217; biofilm formation capabilities Bursac <em>et al</em>. deleted the <em>&#955;-</em>prophage from the genome. The deletion of the <em>&#955;-</em>prophage led to a 2.3-fold increased cell number on the anode ongoing with a 1.34-fold increased mean current density (Bursac <em>et al</em>., 2017). Furthermore, we just recently discovered that exogenous riboflavin enhances biofilm formation by the upregulation of the Ornithine-decarboxylase <em>speC</em>. This is probably based on a quorum sensing effect of riboflavin. Taken together the upregulation of <em>speC</em> ongoing with the deletion of the <em>&#955;-</em>prophage leads to a 4-fold increase in current density ongoing with a 6.1-fold increased biofilm formation on the anode.</p>\u0000<p>However, to ensure an optimal performance of the biofilm in BESs, biofilm thickness itself is not sufficient. The biofilm also needs to be conductive. Our aim is to establish the Spytag-/Spycatcher-tool to synthetically steer biofilm conductivity. Spytag and Spycatcher are two protein residues from the fibronectin binding protein of <em>Streptococcus pyogenes</em> (Spy). These two protein residues form a spontaneous isopeptide bond under a variety of temperatures, pH values and buffers (Zakeri et al., 2012). By coupling Spytag and Spyctacher to different outer membrane <em>c</em>-type cytochromes of <em>S. oneidensis</em> the cells are covalently bound to each other while the biofilm remains conductive. In a first application the production of acetoin as one of the top 30 platform chemicals world-wide is desired (US Department of Energy, 2004).</p>\u0000<p>In order to render <em>S. oneidensis</em> producing acetoin instead of the native end product acetate, Bursac <em>et al</em>. deleted the key genes for acetate production and introduced the acteoin production pathway (Bursac <em>et al</em>., 2017). To broaden the substrate spectrum of <em>S. oneidensis</em>&#160;further genes for glucose metabolism were introduced. Through a long term adaption, the glucose degradation, the biofilm formation abilities and the bioelectrochemical performance were significantly enhanced.</p>\u0000<p>Merging all genetic optimizations ","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":"44631446","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":"CRISPR interference knockdown screen identifies novel proteins involved in formation of structured macrocolonies in Staphylococcus aureus.","authors":"M. Kjos, D. M. Angeles, Marita Torrisen Mårli, Maria Victoria Heggenhougen, Vincent de Bakker, Xue Liu, J. Veening","doi":"10.5194/biofilms9-105","DOIUrl":"https://doi.org/10.5194/biofilms9-105","url":null,"abstract":"<p><em>Staphylococcus aureus</em> biofilms play important roles during infection. The main components of these biofilms are well studied; however, we lack the full understanding of factors and genes involved in regulation of biofilm formation. To screen for essential and non-essential biofilm regulatory genes in <em>S. aureus</em>, we have created a pooled inducible CRISPR interference library. The pooled library is designed to allow knockdown of every transcriptional unit in the <em>S. aureus</em> genome, thus targeting both essential and non-essential genes. We used our library in <em>S. aureus</em> Newman, a strain which forms structured macrocolonies on agar plates. We performed an unbiased screen of 1500 macrocolonies and found 10 macrocolonies with stably altered structures. The genotypes of these macrocolonies were determined by sequencing the single guide RNAs of the CRISPR interference system. As a proof of the validity of the approach, we identified several genes previously reported to be implicated in biofilm and macrocolony formation, including <em>ica</em>-genes, and metabolic genes of the TCA-cycle and gluconeogenesis. In addition, three new genes (two encoding putative enzymes and one hypothetical genes) whose depletion resulted in completely altered macrocolonies were also identified. The molecular mechanisms explaining the roles of these proteins in biofilm formation are currently under investigation.</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":"44808326","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":"Structural differences of biofilms","authors":"Daniel Kleine, P. Breuninger, A. Maus, S. Antonyuk, R. Ulber","doi":"10.5194/biofilms9-109","DOIUrl":"https://doi.org/10.5194/biofilms9-109","url":null,"abstract":"Biofilms consist of bacteria immobilized in extracellular polymeric substances (EPS) with a complex three-dimensional morphology. This inevitably results in gradients (concentration, cell count, pH, etc.) directly affecting the overall behavior of biofilms . Yet, comparatively little is known about the influence of surface structures beneficial for biofilms as production platforms . This understanding is indispensable to establish stable and highly productive biofilm processes. In this study, the model organism Lactococcus lactis subsp. lactis was used, which produces the antimicrobial peptide nisin (E234). Even though its potential for clinical use has been recognized over the past two decades and the application extended to biomedical fields, its widespread use is restricted due to high production costs and relatively low yields . Within this study, microstructured metallic substrata were investigated. All surface structures were characterized via optical profilometry and L. lactis biofilms were cultivated in custom built flow cells. Biofilm morphology was analyzed via optical coherence tomography (OCT) and qRT-PCR was used to analyze relative gene expression levels of nisin genes. Biofilm thickness as well as mushroom count varied depending on the substratum used. This morphological dependency on the surface structure rather than solely on fluid dynamics was demonstrated with a hybrid substratum which was only partly structured. Two separate and morphologically distinct sections were further investigated in order to identify structure-based variations in gene expression. Increased gene expression levels were detected for all genes investigated in the sample of the mushroom rich biofilm section. For the structural gene nisA and nisP, a gene involved in nisin processing, particularly high levels were detected. This indicates an increased activity of the entire nisin gene cluster. Even though mRNA levels cannot directly be linked to respective product titers, it is rather interesting to see different behaviors of biofilm sections on the transcriptional level. In addition to the influence of the substratum surface on biofilm morphology, this knowledge can be used to design biofilm processes based on beneficial surface structures.","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":"45053713","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":"Surface Functionalization-Dependent Physicochemical Interactions between Nanoparticles and the Biofilm EPS Matrix","authors":"D. Hiebner, Caio H. N. Barros, Laura Quinn, S. Vitale, Eoin Casey","doi":"10.5194/biofilms9-93","DOIUrl":"https://doi.org/10.5194/biofilms9-93","url":null,"abstract":"The contribution of the biofilm extracellular polymeric substance (EPS) matrix to reduced antimicrobial susceptibility in biofilms is widely recognised. As such, directly targeting the EPS matrix is a promising biofilm control strategy that allows for efficient disruption of the matrix to allow an increase in susceptibility to antibiofilm agents. To this end, engineered nanoparticles (NPs) have received considerable attention. However, the fundamental understanding of the physicochemical interactions occurring between NPs and the EPS matrix has not yet been fully elucidated. An insight into the underlying mechanisms involved when a NP interacts with molecules in the EPS matrix will aid in the design of more efficient systems for biofilm control. The use of highly specific fluorescent probes in confocal laser scanning microscopy (CLSM) to illustrate the spatial distribution of EPS macromolecules within the biofilm is demonstrated. Three-dimensional (3D) colocalization analysis was used to assess the affinity of differently functionalized silica NPs (SiNPs) for specific EPS macromolecules from Pseudomonas fluorescens biofilms. Results show that both the charge and surface functional groups of SiNPs dramatically affect the extent to which SiNPs interact and localize with EPS macromolecules, including proteins, polysaccharides, and DNA. This research not only develops an innovative strategy for biofilm-nanoparticle interaction studies but also provides a platform on which to build more efficient NP systems for 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":"43973167","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":"Bacteria Adhesion on Polydimethylsiloxane Surfaces Impacted by Material Viscoelasticity or Surface Chemistry?","authors":"Fei Pan, Stefanie Altenried, Mengdi Liu, D. Hegemann, Ezgi Bülbül, J. Moeller, W. Schmahl, K. Maniura‐Weber, Q. Ren","doi":"10.5194/biofilms9-131","DOIUrl":"https://doi.org/10.5194/biofilms9-131","url":null,"abstract":"Fei Pan, Stefanie Altenried, Mengdi Liu, Dirk Hegemann, Ezgi Bülbül, Jens Moeller, Wolfgang W. Schmahl, Katharina Maniura-Weber, and Qun Ren Laboratory for Biointerfaces, Empa, Switzerland (fei.pan@empa.ch) Department of Earthand Environmental Sciences, Ludwig Maximilian University of Munich, Theresienstrasse 41, 80333 Munich, Germany Laboratory of Advanced Fibers, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland Laboratory of Applied Mechanobiology, Department of Health Sciences and Technology, ETH Zurich, 8093 Zurich, Switzerland","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":"46532663","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":"Alanine racemase as target to inhibit the Campylobacter jejuni biofilm formation by L and D-amino acids","authors":"Bassam A. Elgamoudi, T. Taha, V. Korolik","doi":"10.5194/biofilms9-137","DOIUrl":"https://doi.org/10.5194/biofilms9-137","url":null,"abstract":"The ability of bacterial pathogens to form biofilm is an important virulence mechanism in relation to its pathogenesis and transmission. Biofilms play a crucial role in survival in unfavourable environmental conditions, act as reservoirs of microbial contamination and antibiotic resistance. For intestinal pathogen Campylobacter jejuni, biofilms are considered to be a contributing factor in transmission through the food chain and currently, there are no known methods for intervention. Here we present an unconventional approach to reducing biofilm formation by C. jejuni by the application of D-amino acids (DAs), and L-amino acids (LAs). We found that DAs not LAs, except Lalanine, reduced biofilm formation by up to 70%. The treatment of C. jejuni cells with DAs changed the biofilm architecture and reduced the appearance of amyloid-like fibrils. In addition, a mixture of DAs enhanced antimicrobial efficacy of D-Cycloserine (DCS) up to 32% as compared with DCS treatment alone. Unexpectedly, D-alanine was able to reverse the inhibitory effect of other DAs as well as DCS. Furthermore, L-alanine and D-tryptophan decreased transcript levels of alanine racemase (alr) and D-alanine-D-alanine ligase (ddlA). Our findings suggest that a combination of DAs could reduce biofilm formation, viability and persistence of C. jejuni.","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":"47773540","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":"Comparative assessment of biofilm sampling methods on stainless steel surfaces in a CDC biofilm reactor","authors":"Nissa Niboucha, C. Goetz, J. Jean","doi":"10.5194/biofilms9-136","DOIUrl":"https://doi.org/10.5194/biofilms9-136","url":null,"abstract":"The presence of biofilms on stainless steel surfaces in the dairy industry greatly limits the efficiency of the cleaning procedures. The matrix of extracellular polymeric substances produced by the embedded bacteria is largely responsible for this irreversible binding. Therefore, to detach the biofilm in its entirety from the surface for microbiological identification and physico-chemical characterization is limited with the classical methods commonly used for surface sampling such as swabbing. The objective of this study is to optimize an extraction technique of biofilm formed using a dynamic CDC bioreactor system by a strain of Pseudomonas fluorescens isolated from the dairy industry during a biofilm issue. Three methods: swabbing, scraping and sonic brushing were tested in order to determine which one of these techniques allows a better recovery of the biofilm. They were also compared to sonication which is the standard method established by ASTM International. The results demonstrated that the total viable counts obtained by scraping (8.65 ± 0.07 CFU/cm2) were not significantly different from those achieved by sonication (8.74 ± 0.06 CFU/cm2) in contrast to the other two approaches, while scanning electron microscopy showed an effective removal of biofilms from surfaces by sonic brushing. In conclusion, other combinations including brushing, sonication and/or scraping must be investigated for representative sampling of biofilm on the surfaces of dairy plants.","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":"41904017","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}