Academic literature on the topic 'Biofilm monitoring'
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Journal articles on the topic "Biofilm monitoring"
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Lewandowski, Z., and H. Beyenal. "Biofilm monitoring: a perfect solution in search of a problem." Water Science and Technology 47, no. 5 (March 1, 2003): 9–18. http://dx.doi.org/10.2166/wst.2003.0267.
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The main problem with monitoring biofilms is data interpretation. Biofilm heterogeneity causes monitored parameters to vary from location to location in the same biofilm, and it is difficult to assess to what extent these variations are caused by biofilm heterogeneity and to what extent they reflect other properties of the biofilm. We have used the concept of discretized biofilms, which is an integrated system of biofilm monitoring and data interpretation, to assess the effect of biofilm heterogeneity on biofilm activity. Using this approach we have estimated that a heterogeneous biofilm can be ten times more active, in terms of glucose consumption rate, than a homogeneous biofilm of the same thickness but with uniformly distributed density.
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Schmid, T., U. Panne, C. Haisch, and R. Niessner. "Biofilm monitoring by photoacoustic spectroscopy." Water Science and Technology 47, no. 5 (March 1, 2003): 25–29. http://dx.doi.org/10.2166/wst.2003.0271.
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The use of photoacoustic spectroscopy (PAS) as a new biofilm monitoring technique is presented. Growth and detachment of biofilms at three different positions inside a flow channel were monitored by photoacoustic measurements in the visible spectral range (λ = 532 nm). The experimental approach allows the investigation of the influence of various process parameters (e.g. pH or flow conditions) on growth and detachment of biofilms. In addition, the distribution of the attached biomass can be monitored by depth-resolved photoacoustic measurements.
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Power, M. E., J. C. Araujo, J. R. van der Meer, H. Harms, and O. Wanner. "Monitoring sulfate-reducing bacteria in heterotrophic biofilms." Water Science and Technology 39, no. 7 (April 1, 1999): 49–56. http://dx.doi.org/10.2166/wst.1999.0326.
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To a laboratory reactor, in which heterotrophic biofilms were grown on stainless steel coupons under aerobic conditions, sulfate-reducing bacteria (SRB) were added in order to elucidate whether and how these microorganisms were going to establish themselves in the biofilm. Polymerase chain reaction for the dissimilatory sulfite reductase gene and in situ hybridization with probes directed against 16S ribosomal RNA were used to detect the SRB in the biofilm. Both methods proved to be suitable tools for monitoring the SRB in these experiments, which lasted seven days. In a first series of experiments, in which the SRB were added after a biofilm had already developed, the SRB could be detected only one day after addition. No evidence was found that the SRB penetrated the biofilm and established themselves in the anaerobic niches which were present. In a second series of experiments, in which the SRB were inoculated together with a seed of aerobic heterotrophic microorganisms, the SRB were present in the biofilm over the whole biofilm depth and for the duration of the experiment. The study suggests that colonization of the steel coupons by the SRB added to the bulk fluid is hampered by the already developed biofilm, even though the heterogeneous biofilm structure and anaerobic zones in the biofilm depth offer the possibility for the SRB to penetrate and establish themselves.
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Fysun, Olga, Alen Maher, Holger Brehm, Bernd Wilke, and Horst Christian Langowski. "Monitoring of Biofilm Development on Surfaces Using an Electrochemical Method." Solid State Phenomena 262 (August 2017): 492–95. http://dx.doi.org/10.4028/www.scientific.net/ssp.262.492.
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Bioleaching is the extraction of metals from ore by microorganisms. Initial attachment and formation of biofilm by microorganisms are very important for the bioleaching due to the mineral oxidation processes. However, very few techniques were proposed to monitor initial stage of biofilms in real time. Therefore, the aim of this work was to probe an electrochemical method on the bacterial biofilm model under the laboratory conditions. It was found that electrochemical method can be suggested for the real time detection of initial phase of P. polymyxa biofilm formation by observation of the potential increase. However, detection of biofilm development at late stages was not successful due to the decrease of the electrochemical potential by full coverage of the test surface. Nevertheless, this technique is supposed as a promising method for early stage detection of desirable biofilms of acidophilic iron oxidizing microorganisms in bioleaching.
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Janknecht, Peter, and Luis F. Melo. "Online Biofilm Monitoring." Reviews in Environmental Science and Bio/Technology 2, no. 2-4 (2003): 269–83. http://dx.doi.org/10.1023/b:resb.0000040461.69339.04.
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Li, J., and P. L. Bishop. "Monitoring the influence of toxic compounds on microbial denitrifying biofilm processes." Water Science and Technology 47, no. 5 (March 1, 2003): 211–16. http://dx.doi.org/10.2166/wst.2003.0323.
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Microelectrode measurements were conducted to obtain nitrate, pH and redox potential profiles within anoxic denitrifying biofilms. The influence of a toxic organic compound (acid orange 7) on biofilm microprofiles was also monitored using microelectrodes. The data provide evidence that the denitrifying biofilms were stratified into an anoxic layer and an anaerobic layer. The anaerobic zone might provide a niche for the biodegradation of recalcitrant organic compounds in biofilms. It was found that acid orange 7 and its biodegradation byproducts had only a slight impact on biofilm nitrate, pH and redox potential profiles.
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Fuchs, S., T. Haritopoulou, M. Schäfer, and M. Wilhelmi. "Heavy metals in freshwater ecosystems introduced by urban rainwater runoff - monitoring of suspended solids, river sediments and biofilms." Water Science and Technology 36, no. 8-9 (October 1, 1997): 277–82. http://dx.doi.org/10.2166/wst.1997.0679.
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Sediments, suspended solids and biofilm samples at different locations of the River Alb near Karlsruhe were analysed for their heavy metal content (Pb, Cu, Cd). The main task of this study was to validate the biofilm method by comparing the measured pollution with the results of long term monitoring programs based on sediments and suspended solid samples. All compartments of the surveyed systems showed increasing heavy metal concentrations towards highly urbanised areas. The translation of data into pollution classes detected similar pollution situations for sediments and biofilms. The presented biofilm method recommends itself as a practicable instrument for assessing the heavy metal pollution in freshwater ecosystems. The easy sampling-technique, the low variability in the detected values and the ecological relevance of biofilms are the obvious advantages of this biofilm monitoring.
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Artiga, P., V. Oyanedel, J. M. Garrido, and R. Mendez. "A novel titrimetric method for monitoring toxicity on nitrifying biofilms." Water Science and Technology 47, no. 5 (March 1, 2003): 205–9. http://dx.doi.org/10.2166/wst.2003.0321.
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A titrimetric method for monitoring toxicity in suspended biomass was applied in order to measure the activity of nitrifying biofilms and to determine the effect of several toxic compounds on the biofilm. Three typical tannery compounds, quebracho extract, NaCl and Cr+3 were selected to study their toxicity on the biofilms. The results obtained showed an acceptable repeatability of the method for all the toxicants tested with an average standard deviation of less than 10%. Biofilm systems showed higher resistance to the toxicants, when the results obtained using suspended nitrifying biomass, were compared with those found in the literature. The IC50 obtained with quebracho was 8.8 g/L of quebracho extract, while around 65% of maximum activity was attained with 8.7 g/L of NaCl or 120 mg/L Cr+3. The quebracho extract, NaCl and Cr+3 were 26%, 38% and 18%, respectively, less toxic in the biofilm system than for a suspended biomass culture.
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Sultan, Andi Rofian, Mehri Tavakol, Nicole A. Lemmens-den Toom, Peter D. Croughs, Nelianne J. Verkaik, Annelies Verbon, and Willem J. B. van Wamel. "Real time monitoring of Staphylococcus aureus biofilm sensitivity towards antibiotics with isothermal microcalorimetry." PLOS ONE 17, no. 2 (February 16, 2022): e0260272. http://dx.doi.org/10.1371/journal.pone.0260272.
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Biofilm-associated infections with Staphylococcus aureus are difficult to treat even after administration of antibiotics that according to the standard susceptibility assays are effective. Currently, the assays used in the clinical laboratories to determine the sensitivity of S. aureus towards antibiotics are not representing the behaviour of biofilm-associated S. aureus, since these assays are performed on planktonic bacteria. In research settings, microcalorimetry has been used for antibiotic susceptibility studies. Therefore, in this study we investigated if we can use isothermal microcalorimetry to monitor the response of biofilm towards antibiotic treatment in real-time. We developed a reproducible method to generate biofilm in an isothermal microcalorimeter setup. Using this system, the sensitivity of 5 methicillin-sensitive S. aureus (MSSA) and 5 methicillin-resistant S. aureus (MRSA) strains from different genetic lineages were determined towards: flucloxacillin, cefuroxime, cefotaxime, gentamicin, rifampicin, vancomycin, levofloxacin, clindamycin, erythromycin, linezolid, fusidic acid, co-trimoxazole, and doxycycline. In contrast to conventional assays, our calorimetry-based biofilm susceptibility assay showed that S. aureus biofilms, regardless MSSA or MRSA, can survive the exposure to the maximum serum concentration of all tested antibiotics. The only treatment with a single antibiotic showing a significant reduction in biofilm survival was rifampicin, yet in 20% of the strains, emerging antibiotic resistance was observed. Furthermore, the combination of rifampicin with flucloxacillin, vancomycin or levofloxacin was able to prevent S. aureus biofilm from becoming resistant to rifampicin. Isothermal microcalorimetry allows real-time monitoring of the sensitivity of S. aureus biofilms towards antibiotics in a fast and reliable way.
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Savilov, E. D., E. V. Anganova, O. A. Noskova, and A. V. Dukhanina. "Bacteria Biofilms in Purulent-Septic Infections." Acta Biomedica Scientifica 4, no. 5 (November 14, 2019): 38–42. http://dx.doi.org/10.29413/abs.2019-4.5.6.
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The causative agents of many infectious diseases can exist in the form of biofilms.The aim of the workis to study of the frequency of occurrence and the degree of activity of biofilm formation of microorganisms isolated from different locus in purulent-septic infections.Materials and methods.Fifteen strains isolated from patients with purulent-septic infections were examined. Biofilms were determined by the ability to adsorption a crystalviolet to ethanol.Results. 73,3 ± 11,4 % strains had biofilms (including gram-negative bacteria – 69,2 ± 11,9 %; Staphylococcus – 100,0 %; p < 0,05).The degree of activity of formation of biofilm by gram-negative bacteria was higher than Staphylococcus (0,302 ± 0,04 и 0,134 ± 0,01 units of optical density; p < 0,01). The highest activity of formation of biofilm was detected in K. pneumoniae isolated from patients with sepsis. Strains from clinically important locus (blood, sputum, wound discharge, abdominal fluid) had biofilms in 75,0 %; from locus of monitoring – 66,7 %. The pathogens isolated from locus of the monitoring were characterized by an average degree of activity of biofilm formation (0,180–0,360 units of optical density). Strains from clinically important locus (blood and sputum from patients with sepsis) had a highdegree of biofilm formation (more than 0,360 units of optical density). Conclusion. In most cases, strains were characterized by the presence of biofilms and differed in degrees activity of biofilm formation depending on locus.
Dissertations / Theses on the topic "Biofilm monitoring"
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Srikumar, Vivek. "Microbial biofilm monitoring by Electrochemical methods." Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-302540.
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Hospital Acquired Infections and equipment contamination are some of the biggest issues faced by the healthcare industry worldwide. These infections generally range from mild to life threatening human infections which lead to increased costs and prolonged hospitalization time. The primary factor which caused these issues were biofilm forming bacteria which are able to withstand medications and defend themselves from various cleaning procedures. Another aspect which make these bacteria troublesome is that they are able to hide inside the biofilm, thus evading a lot of diagnostic tests. The methods used to detect these biofilms are unfortunately toxic to cells and cannot be used in vivo. Though there is enough data on the formation of biofilm on abiotic surfaces, the data present on the biophysical properties, structural organizations within the biofilm or their viscoelastic properties is very limited. In this master’s degree project, a dynamic monitoring platform is made for 2 different strains of the Salmonella Enteritidis bacteria where their structural and biophysical properties was investigated. Each strain lacks either curli or cellulose which are major components responsible for proper biofilm formation so performing these experiments on them gave us important information on how their properties get affected over time. Bacterial growth monitoring for all the strains were performed by measuring the absorbance every hour over a period of 5h and it was observed that all the strains had a very similar growth pattern until the end of the 4th hour after which they showed very mild differences. The next set of experiments involved using an eQCM to monitor the formation of biofilm on the surface of a quartz chip over 48h. There were differences observed in the biofilm formation pattern and mass deposition which provided clues as to how the biofilm formation and their viscoelastic properties are affected due to the mutations. This led to finding further clues regarding which aspect of biofilm formation is targeted by a specific mutant.
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Maluleke, Moabi Rachel. "Biofilm monitoring and control using electrochemically activated water and chlorine dioxide." Diss., Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-02162007-122247.
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Dec, Luiza Pritsch. "Biofilm utilization for trace metal monitoring in aquatic ecosystem." reponame:Repositório Institucional da UFPR, 2016. http://hdl.handle.net/1884/43550.
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Orientador : Profª. Ph.D Regina Tiemy KishiCoorientador : Prof. D.Sc. Stephan Fuchs
Dissertação (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduação em Engenharia de Recursos Hídricos e Ambiental. Defesa: Curitiba, 15/03/2016
Inclui referências : f.75-78
Resumo: Os metais traço são utilizados na indústria e na agricultura e podem estar presentes em efluentes de mineração e esgoto. Assim, esses elementos atingem o ambiente e podem ser prejudiciais aos organismos, meio ambiente e às pessoas. Um monitoramento representativo é essencial para a gestão dos recursos hídricos e consequente prevenção à poluição. Monitoramentos convencionais da água algumas vezes podem não revelar a real condição do ambiente. Isto acontece devido às condições de lançamento e chegada dos poluentes ao sistema, à tecnologia disponível para quantificar a concentração e devido às características da própria substância monitorada. No caso dos metais traço, estes têm uma atração maior por outras partículas (sólidos suspensos, solo, sedimento, carbono orgânico dissolvido), as quais sedimentam, não permanecendo na coluna d'água. Outro fator a ser considerado é que as fontes de metais traço são geralmente intermitentes e as coletas são não contínuas. Além disto, os limites de detecção são altos e não detectam tais elementos na água. Desta forma, o biofilme é uma técnica alternativa de monitoramento, pois analisa o nível de contaminação em um intervalo de tempo. Para este estudo foram construídos dois amostradores. Amostras de biofilme, água e sedimento foram coletadas ao longo de oito meses para dois pontos de monitoramento, um na bacia do rio Barigüi e outro na bacia do rio Miringuava. Parâmetros de qualidade da água, granulometria e conteúdo de metais traço foram estimados. Os resultados mostram que o biofilme identificou os metais traço em praticamente todas as campanhas, enquanto que para as amostras de água isto não aconteceu. As amostras de sedimento representaram a poluição, porém não foi possível determinar o tempo da contaminação pelo método de coleta utilizado. O biofilme representou as diferenças no uso e ocupação do solo, representando poluição consistente com cada bacia hidrográfica. Palavras-chave: biofilme, metais traço, monitoramento, rio Miringuava, rio Barigüi.
Abstract: Trace metals are used in industries and agriculture and can be present in mining and sewer effluents. In such context, these elements can enter the environment and be very harmful to organisms, environment and people. A representative monitoring is essential for water resources management and, consequently, pollution prevention. Conventional water monitoring do not always show real environment condition. That happens because of effluent release conditions, pollution arrival system conditions, available technology to identify element concentrations and monitoring substance characteristics. Specifically for trace elements, they tend to adhere to other particles (suspended matter, soil, sediment, DOC) and deposit in riverbed. Other factor is that trace metal sources are usually from intermittent discharges and collections are not continuous. Besides that, usual techniques have high quantification limit and do not identify these elements in water. Thus, biofilm is an alternative monitoring technique for trace metals evaluation since it analyses contamination level in a time space. For this study, two biofilm samplers were constructed. Biofilm, water and sediment samples were collected for an eight month period in two monitoring sites, Barigüi and Miringuava watershed. Water quality parameters, granulometry, and trace metals content were estimated. Results showed that biofilm identified metals in almost every campaign, while water samples did not. On the other hand, sediment samples represented pollution but it was not possible to determine the contamination time by the used collection method. Biofilm also represented differences in soil use and occupation, representing consistent pollution potential for each basin. Keywords: biofilm, trace metals, monitoring, Miringuava River, Barigüi River.
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Roßteuscher, Tobias. "Online monitoring of biofilm in microchannels with thermal lens microscopy." kostenfrei, 2009. http://mediatum2.ub.tum.de/node?id=734672.
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Evans, Emily Amaya. "Ultrasonic reflectometry for monitoring biofilm growth on water treatment membranes." Diss., Connect to online resource, 2005. http://wwwlib.umi.com/cr/colorado/fullcit?p1427775.
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Yang, Jingjing. "Controlling and monitoring of deammonification process in moving bed biofilm reactor." Licentiate thesis, KTH, VA-teknik, Vatten, Avlopp och Avfall, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-98624.
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It is considered that partial nitrification combined with anammox, named deammonification, is more environmental friendly compared with conventional nitrification/denitrification due to decrease energy requirement, low emission of CO2 and N2O. Dissolved oxygen (DO) is a significant parameter influencing the nitrogen removal rate and activity of different microorganisms. A proper level of DO concentration is needed to allow ammonium oxidizing bacteria (AOB) to produce a sufficient amount of NO2--N for anammox reaction. Too high NO2--N levels should be avoided as they cause inhibition effects on anammox bacteria or increase growth of nitrite oxidizing bacteria (NOB). In this study, investigations have been carried out, both in laboratory and pilot scales to evaluate the influence of different aeration strategies (characterized by dissolved oxygen concentration - DO and the ratio between non-aerated and aerated phase duration – R) on the deammonification process applied in the moving bed biofilm reactor (MBBR). Three series of batch tests were conducted in laboratory scale with different DO concentrations (2, 3, 4 mg/l) and R values (0 - continuous aeration; 1/3, 1, 3 – intermittent aeration), the same initial ammonium concentration, volume of the reject water and temperature. It was found that the impact of DO on deammonification was dependent on the R value. At R=0 and R=1/3, an increase of DO caused a significant increase in nitrogen removal rate, whereas for R=1 and R=3 similar rates of the process were observed irrespectively of the DO. The highest nitrogen removal rate of 3.33 gN/m2·d was obtained at R=1/3 and DO=4 mg/l. Significantly lower nitrogen removal rates (1.17 - 1.58 gN/m2·d) were observed at R=1 and R=3 for each examined DO. It was a consequence of reduced aerated phase duration times and lower amounts of residual nitrite in non - aerated phases as compared to R=1/3. Pilot scale experiments were carried out in a MBBR with a working volume of 200 L. The pilot plant has been operated for 1.5 years to remove nitrogen from reject water after dewatering of digested sludge. The activity of different groups of microorganisms in the biofilm was measured by specific anammox activity (SAA), oxygen uptake rate (OUR) and nitrate utilization rate (NUR) tests. The whole operation was divided into seven periods according to different nitrogen loads and different aeration strategies. The highest nitrogen removal rate and efficiency was obtained when DO was 3.5 mg/l and R equaled to 1/3. Activity tests showed that anammox bacteria and AOB play the dominating roles in the biofilm. The average and maximum values of specific anammox activity (SAA) were 3.01 gN/m2·d and 4.3 gN/m2·d, respectively. An average value of 4.0 gO2/m2·d and the maximum value of 5.1 gO2/m2·d was obtained in the oxygen uptake rate for AOB activity tests. Study results showed that application of an appropriate selected aeration strategy reduced energy consumption without any negative impacts on the process. Introduction of anaerobic phases and high nitrogen load enhanced the activity of anammox bacteria and NOB activity was limited.Partiell nitrifikation i kombination med anammoxprocess, som kallas för deammonifikationprocess, anses vara mer miljövänlig jämfört med konventionell nitrifikation/denitrifikation pga minskat energibehov samt låga utsläpp av CO2 och N2O. Löst syre (DO) är en viktig parameter som påverkar hastigheten för kväverening och aktiviteten hos olika mikroorganismer. DO koncentrationer bör vara på en viss nivå för att ammoniumoxiderande bakterier (AOB) skall producera en tillräcklig mängd NO2-N för anammoxreaktionen, men inte heller för hög då hög NO2-N nivå ger en anammoxhämmande effekt eller ökad tillväxt av nitritoxiderande bakterier (NOB). I denna studie har undersökningar utförts både i laboratorie- och pilotskala för att utvärdera inverkan av olika luftningsstrategier, (som kännetecknas av koncentrationen av löst syre - DO och förhållandet (R) mellan tider för icke luftade och luftade faser), på deammonifikationprocessen i en MBBR (Moving Bed Biofilm Reactor). Tre serier av satsvisa försök utfördes i laboratorieskala med olika syre koncentrationer (2, 3, 4 mg/l) och R värden (0 - kontinuerlig luftning; 1/3, 1, 3 - intermittent luftning), men med samma initiala ammonium-koncentration, volym av den rörliga bädden och temperatur. Man fann att effekten av löst syre (DO) på deammonifikationen var beroende på R-värde. Vid R = 0 och R = 1/3, gav en ökning av löst syre (DO) en signifikant ökning i kvävereningshastigheten, medan för R = 1 och R = 3 observerades samma hastighet i processen oberoende av löst syrehalt (DO). Den högsta hastigheten för kväveavskiljning 3,33 gN/m2.d (avskiljningsgraden var lika med 69,5%) erhölls vid R=1/3 och DO=4 mg/l. Betydligt lägre värden (från 1,17 till 1,58 gN/m2.d) observerades vid R=1 och R=3 för varje undersökt halt av löst syre (DO). Det var en följd av minskad varaktighet av luftad fas och mindre mängd av kvarvarande nitrit i icke luftade faser jämfört med R= 1/3. Pilotskaleförsök utfördes i en MBBR med en arbetsvolym på 200 L. Pilotanläggningen har drivits i 1,5 år med att avlägsna kväve från rejektvatten från avvattning av rötslam. Aktiviteten hos olika grupper av mikroorganismer i biofilmen mättes genom tester av specifik anammoxaktivitet (SAA), syreupptagningshastighet (OUR) och nitratutnyttjandegrad (NUR). Driften var uppdelat i 7 perioder med olika kvävebelastning och luftningsstrategier. Den högsta hastigheten och grad av kväveavskiljning erhölls då DO var 3,5 mg/l och R uppgick till 1/3. Aktivitetstester visade att anammoxbakterier och AOB spelade dominerande roller i biofilmen. De genomsnittliga och maximala värden för specifika anammoxaktiviteten (SAA) var 3,01 gO2/m2.d och 4,3 gO2/m2.d, respektive. 4,0 gO2/m2.d som medelvärde och högsta värde på 5,1 gO2/m2.d erhölls för syreupptagningen för AOB aktivitetstester. Studien visade att användning av en lämpligt vald luftningsstrategi minskar energiförbrukningen utan några negativa effekter på processen. Införande av anaeroba faser och hög kvävetillförseln ökar aktiviteten för anammoxbakterier och NOB-aktiviteten begränsades.
QC 20120628
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Mariana, Frida. "Chip-Calorimetric Monitoring and Biothermodynamic Analysis of Biofilm Growth and Interactions with Chemical and Biological Agents." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-191577.
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Over the last years, varieties of technologies for biofilm analysis were developed and established. They work on different principles and deliver information about biofilms on different information levels. In this work, chip-calorimetry was applied as an analytical tool that measures heat produced from biofilms. Any change of metabolism in biofilms is reflected by a changed heat flow. The heat, which is the integral of the heat flow vs. time, is quantitatively related to the growth stoichiometry of the biofilm, as described by the Hess’ Law. The heat flow is related to the growth kinetics with the reaction heat as proportionality factor. The results from the calorimetric measurement thus, deliver general information about growth stoichiometry and kinetics.
The other interpretation of calorimetric results bases on the assumed proportionality between heat flow and oxygen consumption rate (- 460 kJ/mol ). This ratio is called oxycaloric equivalent. Because in case of aerobic growth the majority of oxygen is consumed in catabolic processes during the electron transport phosphorylation, calorimetry is assumed to provide information about the catabolic side of the metabolism.
The newly developed chip-calorimeter applied in this work is much more suitable for biofilm studies compared to conventional microcalorimeters due to the flow-through design of the calorimetric chamber. The measurement of undisturbed growing biofilms and the comparison with conventional biofilm analysis tools (i.e. plate counts, confocal laser scanning microscopy (CLSM), and the determination of intermediates’ concentrations (e.g. ATP)) demonstrate the proper functionality of the calorimetric method and the related cultivation procedure by delivering measurement results in the range of literature values.
However, when the biofilms were challenged with antimicrobial agents i.e. antibiotics, bacteriophage, and predatory bacteria, the calorimetric results surprisingly deviated from the reference analyses. By combining the results of the calorimetric and reference analyses, additional information about the antimicrobial effects on biofilms can be acquired. Combination of heat measurement and plate counts, which is one of the most conventional approaches, demonstrated that antimicrobials (especially the bactericidal acting kanamycin) could cause the loss of culturability while the cells were still metabolically active. The measurement of ATP content resulted in values out of the typical range, which indicated that antimicrobial treatments disturbed the cellular ATP regulation and the ATP concentration was no longer linearly correlated to the cell number. ATP measurements are therefore not suitable for antimicrobial susceptibility testing.
The comparison of heat profiles with the biovolume determined by quantification of microscopic images shows an elevated cell specific heat production rate after the introduction of some antimicrobials (antibiotics and bacteriophage). In case of antibiotics, this can be explained as a consequence of the bacterial defense mechanisms. Most of the described defense mechanisms against antibiotics need biological energy and therefore drive the electron transport phosphorylation (ETP). In case of biofilm treatments with bacteriophage, the trigger of increasing ETP might be the synthesis of phage proteins, hull material, and genetic information molecules. In aerobic conditions, oxygen is used as terminal electron acceptor. Elevated ETP leads therefore to an increase in oxygen consumption, which correlates to the heat production using oxycaloric equivalent as a factor. These correlations explain the increase of cell specific heat productions as biofilms were challenged by antibiotics and bacteriophage. However, also a decrease of specific heat production was observed (in case of predatory bacteria). Here, the predatory bacteria activity caused various damages in host cells, including the interruption of ETP.
With these experiments, chip-calorimetry was demonstrated as a promising complementary tool in biofilm research, which provides deeper insights about metabolic activity and alterations. It benefits from the noninvasive handling and the online, real-time measurement that allow the method to be applied for monitoring purposes. Furthermore, its miniaturized dimension allows easy integration in more complex analytic systems and also reduces experiment costs with minimal media/chemical consumption.
This thesis also demonstrates the potential development of chip-calorimetry to be more suitable for routine analyses. The use of superparamagnetic beads as matrix to grow biofilms allows regulated transfer of biofilm samples into and from the measurement chamber. This was an initial step towards automation and higher-throughput analysis.
One further outcome of the thesis is based on the highly interesting fact about the elevated heat production rate of the host cells induced by the phage infection observed in the chip- calorimetric experiments. The volume specific detection limit of the chip-calorimeter is lower compared to a commercial microcalorimeter. Thus, the infection effect of phages was additionally measured in microcalorimeter to get better quantitative information about the thermal effect of the infection. The results showed that the immediate heat increase after the addition of phage into the solution of the host cells appeared to be quantitatively related to the infection factor, MOI (Multiplicity of Infection).
Unfortunately, microcalorimetric measurements in closed ampoules are often subjected to the oxygen limitation. Thus, this problem of microcalorimetric measurement has been addressed. The combination of experimental results and mathematical modeling showed that the rate of metabolism in the static ampoules is defined by the diffusion rate of oxygen into media. This factor has to be considered while designing biological experiments in closed calorimetric measuring chambers and interpreting the calorimetric results for their biological meaning. Some possible solutions to overcome the oxygen bioavailability problem are e.g. to design the experiments with low biomass, or by using media with elevated density to float the biomass at the interface to air and thus to reduce the diffusion path.
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Estrada, Leypón Oscar Emilio. "Micro-Nano-Bio Systems for on-line monitoring of in vitro biofilm responses." Doctoral thesis, Universitat Ramon Llull, 2015. http://hdl.handle.net/10803/300595.
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El treball presentat en aquesta tesi doctoral te com objectiu principal la contribució en el camp de la microbiologia per entendre el biofilms i el possible control de desenvolupament mitjançant l’ús de mètodes i enfoc multidisciplinari. Els biofilms estan definits com comunitats de microorganismes que creixen envoltats en una matriu exopolisacárida i s’adhereixen a una superfície inert o teixit viu. La formació dels biofilms bacterians tenen un gran interès en microbiologia clínica degut al desenvolupament d’infeccions que son causades pel contacte directe o per colonització de dispositius mèdics implantats i pròtesis. Actualment es consideren causa de més del 60 % de les infeccions bacterianes. El problema dels biofilms bacterians a nivell clínic es que mostren millor resistència a antibiòtics arribant inclús a ser de 500 a 5000 cops més resistents a agents antimicrobians comparant amb la mateixa bactèria planctònica (bactèria en suspensió). Hi ha hagut moltes temptatives d’adaptar mètodes a laboratoris clínics on es reprodueixen les condicions pel desenvolupament de biofilms, però encara no s’ha arribat a obtenir òptims protocols estàndard per a aquest propòsit de monitoritzar la formació i toxicitat a temps real. Ha crescut l’interès en disseny, desenvolupament i utilització de dispositius de microfluídica que poden emular els fenòmens biològics que ocorren amb diferents geometries, dinàmica de fluids i restriccions de transport de biomassa en microambients fisiològics.
La recerca descrita en aquesta tesis s’ha dut a terme amb diferents mètodes “label-free” basats en la variació acústica y/o propietats elèctriques per a la monitorització de biofilms. El treball presentat en la monografia descriu un dispositiu “custom-made” per a la utilització d’Espectroscòpia de impedància electroquímica com a eina útil per a l’obtenció d’informació d’adherència i formació de biofilms. El fet d’afegir nanopartícules com a segon biosensor permet la correlació de biofilm amb la seva toxicitat a temps real per a la detecció del punt òptim de tractament de biofilms. Finalment el disseny d’aquesta tecnologia s’utilitza per l’assaig de la resposta de biofilms a antibiòtics com a model in vitro d’infeccions causades per biofilms.El trabajo presentado en esta tesis doctoral tiene como principal objetivo la contribución en el campo de la microbiología para entender los biofilms y el posible control de desarrollo mediante el uso de métodos y enfoque multidisciplinar. Los biofilms están definidos como comunidades de microorganismos que crecen embebidos en una matriz exopolisacárida y se adhieren a una superficie inerte o tejido vivo. La formación de los biofilms bacterianos tiene un gran interés en microbiología clínica debido al desarrollo de infecciones que son causadas por contacto directo o por colonización de dispositivos médicos implantados y prótesis. Actualmente se consideran la causa de más del 60 % de las infecciones bacterianas. El problema de los biofilms bacterianos a nivel clínico es que muestran mejor resistencia a antibióticos llegando incluso a ser de 500 a 5000 veces más resistentes a agentes antimicrobianos comparado a la misma bacteria planctónica (bacteria en suspensión). Ha habido muchas tentativas de adaptar métodos a laboratorios clínicos donde se reproducen las condiciones para el desarrollo de biofilms, pero aún no se ha llegado a obtener óptimos protocolos estándar para este propósito de monitorizar la formación y toxicidad en tiempo real. Ha crecido el interés en diseño, desarrollo y utilización de dispositivos de microfluídica que puedan emular los fenómenos biológicos que ocurren con diferentes geometrías, dinámica de fluidos y restricciones de transporte de biomasa en microambientes fisiológicos. La investigación descrita en esta tesis se lleva a cabo con diferentes métodos “label-free” basados en variación acústica y/o propiedades eléctricas para la monitorización de biofilms. El trabajo presentado en esta monografía describe un dispositivo “custom-made” para la utilización de Espectroscopia de impedancia electroquímica como herramienta útil para obtener información de adherencia y formación de biofilms. El hecho de añadir nanopartículas como segundo biosensor permite la correlación de biofilm con su toxicidad en tiempo real para la detección del punto óptimo del tratamiento de biofilms. Finalmente el diseño de esta tecnología es usada para el ensayo de la respuesta de biofilms a antibióticos como modelo in vitro de infecciones causadas por biofilms.
The work presented in this thesis has the main aim to contribute in the field of clinical microbiology to understand the biofilms and the possible of development through the use of methods with multidisciplinary approach. Biofilms are defined as communities of microorganisms that grow embedded in a matrix of exopolysaccharides and adhering to an inert surface or living tissue. The formation of bacterial biofilms has an interest in clinical microbiology with the development of infections that usually arise from either direct contact or the colonization of implanted medical devices and prostheses. Currently they are considered the cause of over 60% of bacterial infections. The problem of bacterial biofilms at clinical level is showing great resistance to antibiotics, so that the biofilm bacteria are 500 to 5000 times more resistant to antimicrobial agents that the same bacteria grown in planktonic cultures (bacteria in suspension). There have been attempts to adapt methods to clinical laboratories where they reproduce the conditions of biofilms, but have not yet adopted an optimal standard protocol for this purpose to follow-up the formation and toxicity in real-time. There has been a growing interest in design, development and utilization of microfluidic devices that can emulate biological phenomena that occur in different geometries, fluid dynamics and mass transport restrictions in physiological microenvironments. The research described in this thesis deals with different label-free methods based on variation of acoustic and electric properties for biofilm monitoring. The work presented in this monograph describe a custom-made device for using electrochemical impedance spectroscopy (EIS) as useful tool to obtain information of adherence and formation of biofilms. The addition of nanoparticles as toxicity biomarker allows the correlation of biofilm formation with its toxicity in real-time for detention of the optimal point for biofilm treatment. Finally the design of this technology is used for testing the biofilm response to antibiotic as in vitro model of biofilm-related infection.
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TUCCI, MATTEO. "MICROBIAL ELECTROCHEMICAL SENSORS FOR FRESHWATER AND WASTEWATER MONITORING." Doctoral thesis, Università degli Studi di Milano, 2020. http://hdl.handle.net/2434/702269.
Full textAbstract:
Freshwater is essential for socioeconomic development, health of the population and equilibrium of the ecosystem. However, pollution generated by human activities often degrade the quality of this vital resource. In order to address this problem with effective management strategies, continuous assessment of freshwater and wastewater status is necessary. Microbial electrochemical systems (MESs) are attracting increasing attention as sensing tools, due to their low-cost, sustainability, portability, generation of continuous on-line signal and low involvement of operators. In this dissertation, the implementation of MESs as sensors in two different environmental contexts is discussed: wastewater treatment monitoring and agriculture-related pollutants detection. Different prototypes were designed according to their specific application and their detection capabilities were investigated. Regarding the monitoring of wastewater treatment process, floating Microbial Fuel Cells (MFCs) were tested as sensors for organic matter, a parameter that is currently measured with the labour-intensive and time-consuming BOD5 test. The first prototype consisted of a floating frame holding two carbon cloth electrodes separated by a polypropylene felt and a clay layer. The biosensor was tested in the lab using real wastewater as both electrolyte and inoculum, and a calibration curve was obtained. However, when the device was tested in the plant of Carimate (CO), a strong influence of light irradiation on the signal was noticed. During a month of operations, a correspondence between the peaks of voltage and of the peaks of organic load was present, but the signal was delayed of about two days. To further understand the influence of different environmental factors on the current signal, a new device was conceived and compared with the previous configuration. This time the experimentation was carried out at the plant of Bresso Niguarda (MI). The new setup consisted in a cylindrical terracotta separator sealed at one end and held perpendicularly to the wastewater surface by a plastic floater. The carbon cloth anode was placed outside the cylinder, while a cathode of the same material was located inside. Light irradiation, temperature, sCOD and nitrates were continuously monitored for about 20 days. An automatic sampler was built to obtain wastewater samples every two hour every day. The correlation between the physical-chemical parameters and the cell voltages was quite poor, especially for the floating type, which was often subjected to the inversion of the electrodes potential. This was probably due to oxygen diffusion in the first layer of wastewater. The microbial analysis of the biofilms confirmed this aspect, as aerobic strains (e.g. Nocardicaceae) were found on the anodes, and electrogenic bacteria usually present on anodes were found on the cathodes (i.e. Geobacteriaceae). To monitor agriculture-related pollutants (i.e. herbicides), amperometric biosensors based on the inhibition of cyanobacterial photocurrent were studied. Many herbicide compounds are harmful to humans and the environment, and they are currently measured with classic analytic techniques (e.g. HPLC, GC-MS, etc.), which are expensive and time consuming. To build the first prototype, Anabaena variabilis cells were entrapped on a carbon felt electrodes using an alginate hydrogel, and p-benzoquinone was used as electron shuttle to sustain the electron transfer. With this device it was possible to obtain concentration-current calibration curves for two commonly used herbicides (i.e. diuron and atrazine), and the obtained linear range was suitable for environmental analysis. However, to build a long lasting device, a mediatorless configuration is preferable, as the redox mediator is cytotoxic and can undergo photodegradation. For this reason, a new biosensor was created: a paper-based electrode coated with carbon nanotube paint and a titanium nanolayer was used as substrate for the formation of a Synechocystis wt. biofilm. Whit this configuration, only a presence/absence inhibition signal could be obtained for atrazine and diuron, while the herbicide paraquat temporarily enhanced the electron transfer due to its redox mediator capabilities. Nevertheless, this biosensor was able to maintain its sensitivity even after it was kept in the fridge for 22 days, proving its potential as long-lasting device which can be easily stored or shipped after preparation. These results demonstrated that microbial electrochemical sensors are a promising technology for sensing applications, with a great potential for the creation of a smart, diffuse grid of low-cost sensors for the continuous monitoring of water quality. However, further improvements are needed in order to reduce the response time, improve the sensitivity and discern between the influence of different environmental factors on the signal.
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Brain, Stephen. "Monitoring microbial biofilms." Thesis, London South Bank University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337401.
Full textBooks on the topic "Biofilm monitoring"
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Melo. Biofilm Monitoring (Integrated Environmental Technology). IWA Publishing, 2003.
Find full textBook chapters on the topic "Biofilm monitoring"
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Paredes, Jacobo, Imanol Tubía, and Sergio Arana. "Biofilm impedance monitoring." In Handbook of Online and Near-real-time Methods in Microbiology, 102–36. Boca Raton, FL : Taylor & Francis Group, 2017.: CRC Press, 2017. http://dx.doi.org/10.1201/9781315153568-6.
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Becerro, S., J. Paredes, and S. Arana. "Interdigitated Biosensor for Multiparametric Monitoring of Bacterial Biofilm Development." In IFMBE Proceedings, 880–83. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-00846-2_218.
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Salvago, G., G. Fumagalli, P. Cristiani, and G. Rocchinp. "Biofilm Monitoring and On-line Control: 20-Month Experience in Seawater." In Microbial Corrosion, 301–13. London: CRC Press, 2022. http://dx.doi.org/10.1201/9780367814106-26.
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Becerro, Sheila, Jacobo Paredes, and Sergio Arana. "Multiparametric Biosensor for Detection and Monitoring of Bacterial Biofilm Adhesion and Growth." In IFMBE Proceedings, 333–36. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-11128-5_83.
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Mukherjee, Dipro, Sayantani Garai, Dibyajit Lahiri, Moupriya Nag, and Rina Rani Ray. "Monitoring Cell Distribution and Death in Sessile Forms of Microbial Biofilm: Flow Cytometry-Fluorescence Activated Cell Sorting (FCM-FACS)." In Springer Protocols Handbooks, 299–316. New York, NY: Springer US, 2021. http://dx.doi.org/10.1007/978-1-0716-1378-8_13.
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Priyadarshini, Anjali, Archana Gupta, Kusum Rani, and Tanya Singh. "Monitoring Gene Expression in Sessile Forms of Microbial Biofilm: Polymerase Chain Reaction (PCR) and Real-Time Polymerase Chain Reaction (RT-PCR)." In Springer Protocols Handbooks, 317–43. New York, NY: Springer US, 2021. http://dx.doi.org/10.1007/978-1-0716-1378-8_14.
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Bott, T. R. "Industrial Monitoring — Cooling Water Systems." In Biofilms — Science and Technology, 661–69. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-1824-8_58.
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Holah, J. T. "Industrial Monitoring: Hygiene in Food Processing." In Biofilms — Science and Technology, 645–59. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-1824-8_57.
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Meyer, M. T., V. Roy, W. E. Bentley, and R. Ghodssi. "A Microfluidic Platform for Optical Monitoring of Bacterial Biofilms." In IFMBE Proceedings, 426–29. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-14998-6_108.
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Yuca, Esra, and Urartu Özgür Şafak Şeker. "Monitoring Molecular Assembly of Biofilms Using Quartz Crystal Microbalance with Dissipation (QCM-D)." In Methods in Molecular Biology, 25–33. New York, NY: Springer US, 2022. http://dx.doi.org/10.1007/978-1-0716-2529-3_3.
Full textConference papers on the topic "Biofilm monitoring"
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Licina, George J. "Field Experience With On-Line Monitoring of Biofilm Activity." In 2008 7th International Pipeline Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/ipc2008-64141.
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Piping reliability is critical to oil production, oil sands processing, refineries, power plants, pulp and paper mills, and various other industries. Corrosion, including Microbiologically Influenced Corrosion (MIC), is a primary degradation mechanism in pipelines. MIC of pipeline materials has been shown to occur in virtually all water systems and has caused expensive unplanned outages, the need for local repairs, and, in some cases, complete system replacement. The control of biofilm on surfaces is the most effective tool for mitigating MIC. Effective monitoring for biofilms also helps to avoid the overuse of oxidizing biocides. Biocide overdosing will increase corrosion and can produce catastrophic corrosion effects. Optimized treatments require accurate, on-line monitoring of biofilm activity. Plant experience with an electrochemical biofilm sensor with integrated data acquisition and data analysis capabilities for monitoring biofilm activity on metallic surfaces and the use of that tool for optimizing biocide additions in a variety of environments is described.
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Young Wook Kim, Saeed Esmaili Sardari, Agis A. Iliadis, and Reza Ghodssi. "A bacterial biofilm Surface Acoustic Wave sensor for real time biofilm growth monitoring." In 2010 Ninth IEEE Sensors Conference (SENSORS 2010). IEEE, 2010. http://dx.doi.org/10.1109/icsens.2010.5690301.
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Hnatiuc, M., S. Ghita, L. Inge, and K. Chetehouna. "Study of biofilm evolution using a monitoring water system." In 2019 IEEE 25th International Symposium for Design and Technology in Electronic Packaging (SIITME). IEEE, 2019. http://dx.doi.org/10.1109/siitme47687.2019.8990826.
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Le, Hanh N. D., Victoria M. Hitchins, Ilko K. Ilev, and Do-Hyun Kim. "Monitoring biofilm attachment on medical devices surfaces using hyperspectral imaging." In SPIE BiOS, edited by Israel Gannot. SPIE, 2014. http://dx.doi.org/10.1117/12.2047867.
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Bumah, Violet, Daniella Mason-Meyers, Dawn Castel, Chris Castel, and Chukuka Enwemeka. "Development of pulsed blue light technologies for bacterial biofilm disruption." In Photonic Diagnosis, Monitoring, Prevention, and Treatment of Infections and Inflammatory Diseases 2019, edited by Tianhong Dai, Mei X. Wu, and Jürgen Popp. SPIE, 2019. http://dx.doi.org/10.1117/12.2510699.
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Melnik, Eva, Paul Müllner, Roman Bruck, Michael Lämmerhofer, and Rainer Hainberger. "Biofilm Growth Monitoring on a-Si:H Based Mach-Zehnder Interferometric Biosensors." In Optical Sensors. Washington, D.C.: OSA, 2012. http://dx.doi.org/10.1364/sensors.2012.sth1b.4.
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Amer, Miquel-Angel, Marc Navarro, Antoni Turo, Miguel Garcia Hernandez, Jordi Salazar, and Juan A. Chavez. "Design of a QCM-sensor for on-line monitoring biofilm growth." In 2021 IEEE International Instrumentation and Measurement Technology Conference (I2MTC). IEEE, 2021. http://dx.doi.org/10.1109/i2mtc50364.2021.9459952.
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Saetiew, Jadsada, Panomsak Meemon, Sittichoke Ritpech, and Tassanee Saovana. "Optical topography technique for characterization and monitoring of biofilm thickness uniformity." In 2017 10th Biomedical Engineering International Conference (BMEiCON). IEEE, 2017. http://dx.doi.org/10.1109/bmeicon.2017.8229105.
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Baldoni-Andrey, P., N. Lesage, P. Pedenaud, and M. Jacob. "Detection and Monitoring of Biofilm Growth in the Seawater Sulfate Removal Units." In SPE Produced Water Handling & Management Symposium. Society of Petroleum Engineers, 2015. http://dx.doi.org/10.2118/174562-ms.
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Fraiwan, Arwa, and Seokheun Choi. "A biomicrosystem for simultaneous optical and electrochemical monitoring of electroactive microbial biofilm." In 2015 IEEE Sensors. IEEE, 2015. http://dx.doi.org/10.1109/icsens.2015.7370212.
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