Biofilms最新文献

{"title":"Preventing biofilms by chitosan-based nanoantimicrobials (NAMs)","authors":"E. A. Kukushkina, M. C. Sportelli, N. Ditaranto, R. Picca, N. Cioffi","doi":"10.5194/biofilms9-150","DOIUrl":"https://doi.org/10.5194/biofilms9-150","url":null,"abstract":"Chitosan (CS), a natural non-toxic polysaccharide, shows intrinsic antimicrobial activity against a wide range of pathogens. CS and CS-based biomaterials can be effective additives in food and medicine-related industries to inhibit growth of pathogens. The application of inorganic nanophases, such as metal and metal oxide nanoparticles, has received attention due to their broad and pronounced antimicrobial activity. Upon combination with CS, which can act as stabilizer, with active inorganic nanophases, robust synergistic nanoantimicrobial (NAM) systems can be produced. These hybrid NAMs offer an alternative strategy to fight antimicrobial resistance and overcome limitations of conventional antibiotics. Bioactive ZnO, Cu and Ag nanophases produced by green electrochemical approach [Nanomaterials, 10(3) (2020), 473] and laser ablation in solution [(Coll. Surf. A, 559 (2018), 148-158), (Food packaging shelf, 22 (2019), 1000422)] can be combined with antimicrobial CS to develop synergistic antimicrobial nanohybrids with amplified biological action. CSbased NAMs were preliminary characterized by electron microscopies and spectroscopic techniques. Hybrid NAMs may find application in the control and inhibition of biofilm growth.","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":"46960696","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":"Prediction of biofilm deformation and detachment using shear rheometry, phase-field modeling, and OCT","authors":"Mengfei Li, K. Matous, R. Nerenberg","doi":"10.5194/biofilms9-106","DOIUrl":"https://doi.org/10.5194/biofilms9-106","url":null,"abstract":"In many environmental systems, such as membrane filtration systems, biofilm control is essential, but costly and requiring harsh chemicals. More effective biofilm control may be obtained using a “materials science” approach. Biofilms can be characterized as viscoelastic materials, and biofilm “disruptors” can be characterized for their weakening effect on biofilm mechanical strength. By using a novel mathematical model that incorporates biofilm mechanical properties, fluid flow, and diffusion and reaction of disruptors, better cleaning strategies can be devised.","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":"41730936","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":"Online Analysis of CO2 Production in Electroactive Biofilms by Differential Electrochemical Mass Spectrometry","authors":"F. Kubannek, U. Schröder, U. Krewer","doi":"10.5194/biofilms9-102","DOIUrl":"https://doi.org/10.5194/biofilms9-102","url":null,"abstract":"<p>Electroactive biofilms are routinely characterized in-operando by dynamic electrochemical measurement techniques such as cyclic voltammetry or electrochemical impedance spectroscopy. Since electrical signals can be recorded and processed very quickly, these techniques allow to investigate slow and fast electron transfer processes.</p>\u0000<p>&#160;</p>\u0000<p>In contrast, the dynamics of species production rates are usually not addressed because standard measurement techniques for the quantification of reaction products such as gas chromatography are slow. Instead it is often assumed that species production rates are either directly proportional to the current - under so called turnover conditions - or equal zero - under so called non-turnover conditions.</p>\u0000<p>&#160;</p>\u0000<p>To challenge this assumption, we measured species production rates of a biofilm electrode with a high time resolution by differential electrochemical mass spectrometry (DEMS). An acetate oxidizing biofilm electrode was placed just micrometers away from the mass spectrometer inlet in which enabled us to observe CO₂ production directly at the electrode during cyclic voltammetry (CV) and potential steps.</p>\u0000<p>&#160;</p>\u0000<p>The measurement results showed that the CO₂ production deviates significantly from the expected value calculated from the current by Faraday&#8217;s law under certain operating conditions. We analyze this effect in detail and show that it can be explained with biofilm storage capacities for charge and substrate. These capacities are quantified by deconvoluting the faradaic and non-faradaic currents. [1]</p>\u0000<p>&#160;</p>\u0000<p>Also, the onset of the complete oxidation of acetate to CO₂ during CVs was determined to be just 22 mV above the standard potential for acetate oxidation. Determining this value by directly measuring CO₂ instead of current is advantageous because capacitive effects can be excluded. [1]</p>\u0000<p>&#160;</p>\u0000<p>In conclusion, we demonstrate that electrical current and CO₂ production can be partly decoupled in biofilm electrodes and that DEMS is a valuable technique for analyzing processes in such electrodes.</p>\u0000<p>&#160;</p>\u0000<p>[1] Kubannek, F., Schr&#246;der, U., Krewer, U. (2018). Revealing metabolic storage processes in electrode respiring bacteria by differential electrochemical mass spectrometry. Bioelectrochemistry, 121, 160&#8211;168, doi: 10.1016/j.bioelechem.2018.01.014</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":"47506298","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":"Electrode assisted production of platform chemicals in Rhodobacter sphaeroides.","authors":"Ferdinand Schmid, J. Gescher","doi":"10.5194/biofilms9-135","DOIUrl":"https://doi.org/10.5194/biofilms9-135","url":null,"abstract":"<p>The aim of this study was to establish cathodic biofilms of the photosynthetic non sulfur purple bacterium <em>Rhodobacter sphaeroides</em> as biocatalyst for the production of platform chemicals from carbon dioxide as carbon source and an electrical current as energy and electron source.&#160; Therefore, <em>R. sphaeroides</em> was cultivated in a bioelectrical system (BES) in which light, CO₂ and a stable current were provided. Chronopotentiometric measurements revealed the cathode potential necessary to maintain the applied current of I = 22,2 &#181;A/cm&#178;. Interestingly, exposure of <em>R. sphaeroides</em> to the antibiotic kanamycin lead to increased biofilm production on the cathode although the organism expressed the necessary resistance marker. This enhanced biofilm production raised the potential by 170 mV to E = -1 V compared to the wildtype (E = -1,17 V) and hence increased the efficiency of the process. To date, the molecular basis of this effect remains unclear and is under investigation using a proteomic approach. To elucidate, if the productivity of <em>R. sphaeroides</em> as a production strain is also enhanced, the production of acetoin was established as proof of principle. After the confirmation of the acetoin production under autotrophic conditions, various approaches to increase the space-time yields of the process were conducted and their effect will be presented.&#160;&#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":"48370362","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":"Identifying biofilm regulators as novel targets for antimicrobial drug design","authors":"M. Dostert, Corrie R. Belanger, T. Blimkie, R. Falsafi, B. K. Dhillon, Amy H. Lee, R. Hancock","doi":"10.5194/biofilms9-119","DOIUrl":"https://doi.org/10.5194/biofilms9-119","url":null,"abstract":"<p>Antibiotic treatment regularly fails to cure patients suffering from infections caused by adaptively resistant microbial communities, referred to as biofilms. Even though at least two thirds of all clinical infections are associated with biofilms, there are no biofilm-specific therapies on the market or in clinical trials. <em>Pseudomonas aeruginosa</em> is a remarkably antibiotic resistant, nosocomial pathogen and biofilm-former that causes morbidity and mortality especially in cystic fibrosis and immunocompromised patients. This project aims to identify regulatory genes associated with drug resistance in <em>P. aeruginosa</em> biofilms to provide novel biofilm-specific targets for the design of potent drugs. A genome-wide screen of <em>P. aeruginosa</em> burn wound isolate UCBPP-PA14 identified 362 genes involved in biofilm formation, including dozens of regulatory and hypothetical genes. I will discuss regulatory as well as metabolic genes corresponding to the known resistome of antimicrobials.</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":"42835838","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":"Mixed-trophies two species biofilms driven by Cyanobacteria for biotechnnological applications","authors":"Katja Bühler, Anna Hoschek, A. Schmid, Ingeborg Heuschkel, R. Karande","doi":"10.5194/biofilms9-80","DOIUrl":"https://doi.org/10.5194/biofilms9-80","url":null,"abstract":"<p>&#160;</p>\u0000<p>Despite photo-biocatalysis developing remarkably and the huge potential of photoautotrophic microorganisms for eco-efficient production scenarios, photo-biotechnology is still in its infancy. The lack of scalable photo-bioreactors that provide efficient light transmission, CO₂ supply, and O₂ degassing and thus enable high cell densities (HCD), constitutes a key bottleneck, especially if cost-sensitive bulk chemicals are the product of choice. Commercialized tubular photo-bioreactors with 100 to 600 mm inner diameter offer a surface area to volume ratio (SA/V) of over 100 m² m^-3 enabling the efficient capturing of incident solar radiation.¹ Here we introduce a new generation of photo-bioreactors based on capillary biofilm reactors. The biofilm is composed of two strains, namely the photoautotrophic strain <em>Synechocystis</em> sp. PCC 6803 and the chemoheterotrophic strain <em>Pseudomonas taiwanensis</em> VLB120, which serves as a biofilm supporter strain. <em>Pseudomonas</em> sp. is lowering the pO₂ in the system, which otherwise would toxify the Cyanobacteria. Furthermore, it produces extrapolymeric substances (EPS) and produces a kind of seeding layer promoting the attachment of <em>Synechocystis</em> sp.. <em>Synechocystis</em> sp. on the other hand produces organic compounds and oxygen consumed by <em>Pseudomonas</em> sp. The system is run completely without any organic carbon source.</p>\u0000<p>Depending on the functionalities engineered into the biofilm forming organisms, these systems can be used for biotechnological applications. Here, we will present data on the physiology of the mixed trophies biofilm, and the challenging conversion of cyclohexane to caprolactone, and further on to 6-hydroxyadipic acid, both being important monomers for Nylon production.</p>\u0000<p>&#160;</p>\u0000<p><strong>References </strong></p>\u0000<ul>\u0000<li>[1] Posten, C. Eng. In Life Science. (2009) 9:165-177</li>\u0000<li>[2] Hoschek, A. et al Bioresource Technology. (2019) 282: 171-178</li>\u0000</ul>\u0000<p>&#160;</p>\u0000<p>tract HTML here.</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":"48875928","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":"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}