TY - CONF A1 - Wen, Keqing A1 - Gorbushina, Anna A1 - Schwibbert, Karin A1 - Bell, Jérémy T1 - A microfluidic platform for monitoring biofilm formation in flow under defined hydrodynamic conditions N2 - Bacterial adhesion on surfaces of medical, water and food applications may lead to infections, water or food spoilage and human illness. In comparison to traditional static and macro flow chamber assays for biofilm formation studies, microfluidic chips allow in situ monitoring of biofilm formation under various flow regimes, have better environment control and smaller sample requirements. In this work, a novel microfluidic platform is developed to investigate biofilm adhesion under precisely controlled bacteria concentration, temperature, and flow conditions. This platform central unit is a single-inlet microfluidic flow cell with a 5 mm wide chamber designed and tested to achieve ultra-homogenous flow in the central area of chamber. Within this area, defined microstructures are integrated that will disturb the homogeneity of the flow, thus changing bacterial adhesion pattern. Here we present the monitoring of bacterial biofilm formation in a microfluidic chip equipped with a microstructure known as micro-trap. This feature is based on a 3D bacteria trap designed by Di Giacomo et al. and successfully used to sequester motile bacteria. At first, fluorescent particles similar in size to Escherichia coli (E. coli) are used to simulate bacteria flow inside the flow cell and at the micro-trap. The turbulences induced by the trap are analyzed by imaging and particle tracking velocimetry (PTV). Secondly, the model strain E. coli TG1, ideal and well described for biofilm studies, is used to analyze biofilm formation in the micro-trap. Therefore, a stable fluorescent strain E. coli TG1-MRE-Tn7-141 is constructed by using Tn7 transposon mutagenesis according to the method described by Schlechter et al. Sequestering of E. coli cells within the micro-trap was followed using epifluorescence microscopy. The novel microfluidic platform shows great potential for assessment of bacterial adhesion under various flow regimes. The performance of structural feature with respect to the generation of turbulences that promote or reduce bacterial adhesion can be systematically examined. The combination of flow analysis and fluorescent strain injection into the microfluidic chip shows that the micro-trap is useful for capturing bacteria at defined positions and to study how flow conditions, especially micro-turbulences, can affect biofilm formation. It represents a powerful and versatile tool for studying the relation between topography and bacteria adhesion. T2 - International Conference on Miniaturized Systems for Chemistry and Life Sciences CY - Katowice, Poland DA - 15.10.2023 KW - Biofilm KW - E. coli KW - Microfluidics KW - Velocimetry KW - Fluorescence PY - 2023 AN - OPUS4-59593 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - von Werder, Julia T1 - Biofilme auf Gebäuden - Biorezeptivität statt Biofilme N2 - Der Vortrag erläutert das Konzept der Gebäudebegrünung mit Biofilmen. Beton wird dabei als künstliches Gestein betrachtet, dessen Besiedelbarkeit durch Mikroorganismen gezielt verbessert werden soll. Ein dreistufiges Testsystem – Laborversuche, simulierte Bewitterung und Freilandtests – analysiert, wie physikalische und chemische Substrateigenschaften das Wachstum beeinflussen. Ein definierter Algen‑Pilz‑Modellbiofilm dient zur reproduzierbaren Bewertung der Besiedlung, erfasst über PAM‑Fluorometrie. Die Ergebnisse zeigen, dass Rauheit, Textur und Porosität entscheidend für Anhaftung, Feuchteretention und Biofilmwachstum sind. Zudem wird deutlich, dass die Organismen hohe Stresstoleranz benötigen, um variierende Umweltbedingungen an realen Fassaden zu überstehen. Insgesamt belegt das Projekt das Potenzial biorezeptiver Betone als low‑tech‑Fassadenbegrünung mit ökologischem Mehrwert. T2 - Workshop Ökologische Campusentwicklung: Wasser und Vegetationsmanagement in Helmholtz-Zentren CY - Potsdam, Germany DA - 03.04.2025 KW - Biofilm KW - Fassade KW - Biorezeptivität KW - Low-tech Begrünung KW - Modellbiofilm PY - 2025 AN - OPUS4-65448 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - von Werder, Julia T1 - Bioreceptive Building Facades: Codesigning with nature N2 - Building envelopes represent a key interface between solid substrates, the biosphere, and the atmosphere, and consequently serve as natural habitats for subaerial biofilms. This study investigates strategies to enhance the bioreceptivity of concrete cladding to support microalgae‑rich biofilms as a sustainable alternative to biocide‑dependent facade systems. Using a controlled dual‑species biofilm model and assessing algal vitality via PAM fluorometry, we examined how concrete composition and surface properties influence colonization dynamics. The results demonstrate that substrate pH and carbonation state are primary determinants of both biofilm establishment and organismal vitality, whereas nutrient supplementation exerts comparatively minor effects. Adhesion assays indicate that moderate mechanical stress can increase biofilm robustness, and laboratory rain simulations show that surface texture and near‑surface porosity promote water retention and enhance biofilm attachment. A synergistic interaction between the algal and fungal components was observed under specific stress conditions, offering a potential explanation for the reduced performance of biofilms when transitioning from ideal laboratory settings to outdoor environments. Overall, the findings highlight that the development of stable, photosynthetically active biofilm facades requires careful optimization of organism growth, physiological performance, and long‑term adhesion to the substrate. T2 - SASBE 2025: Smart and Sustainable Built Environment CY - Lille, France DA - 03.11.2025 KW - Concrete KW - Bioreceptivity KW - Laboratory test KW - Biofilm KW - Fluorometry PY - 2025 AN - OPUS4-65446 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - von Werder, Julia T1 - Greening Concrete with biofilms: Codesigning with nature N2 - uilding envelopes act as artificial lithic surfaces and natural substrates for subaerial biofilms, whose establishment depends on surface bioreceptivity. This study investigates how concrete cladding can be engineered to support microalgae‑dominated biofilms. A multi‑stage experimental framework—ranging from petri‑dish cultivation and adhesion testing to laboratory weathering simulations and outdoor exposure—was applied. A reproducible dual alga–fungus model biofilm enabled controlled assessment, with algal vitality quantified using PAM fluorometry. Results identify pH and carbonation as primary determinants of successful colonization, while nutrient addition has only minor influence. Adhesion tests show that moderate stress can enhance resilience to hydrodynamic forces. Rain‑simulation experiments highlight the importance of surface texture and near‑surface porosity for water retention, microbial attachment, and sustained growth. A synergistic interaction between algae and fungi under stress conditions may explain the poor outdoor performance of biofilms cultivated under ideal laboratory conditions. Overall, optimizing photosynthetic efficiency, organismal growth, and adhesion strength is essential for developing durable algal biofilm‑based façade systems. T2 - 4th International Conference of Sustainable Building Materials CY - Eindhoven, The Netherlands DA - 10.08.2025 KW - Concrete KW - Bioreceptivity KW - Laboratory test KW - Biofilm KW - Fluorometry PY - 2025 AN - OPUS4-65447 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - von Werder, Julia T1 - Gebäudebegrünung mit Biofilmen: Herausforderungen und Chancen N2 - Der Vortrag stellt die Ergebnisse der Forschungsarbeiten zur Biorezeptivität von Betonfassaden sowie der gezielten Applikation von Algen dominierten Biofilmen auf Betonfassaden vor. Insbesondere werden die Anforderungen an eine repräsentative Prüfmethode erläutert. T2 - BuGG-Tag der Forschung und Lehre Gebäudegrün 2024 CY - Leipzig, Germany DA - 26.09.2024 KW - Begrünung KW - Biorezeptivität KW - Beton KW - Biofilm PY - 2024 AN - OPUS4-62221 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - von Werder, Julia T1 - Biorezeptivität und Optimierung von Lehmbaustoffen - Forschung an der BAM N2 - Der Vortrag fasst die Forschungsaktivitäten der BAM in den Themengebieten Biorezeptivität von Beton und Optimierung von Lehmbaustoffen zusammen. Er diente als Kurzpräsentation für eine anschließende Podiumsdiskussion. T2 - Transformationsdialog "Material als Motor" CY - Berlin, Germany DA - 10.10.2024 KW - Biorezeptivität KW - Beton KW - Lehmbaustoffe PY - 2024 AN - OPUS4-62220 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - von Werder, Julia T1 - Living Concrete Walls: Engineering Bioreceptivity and Biofilms N2 - Building envelopes are a natural habitat of subaerial biofilms and can be more or less prone to be colonized (i.e. to be bioreceptive). Focusing on the added value of biofilms on manmade substrates represents new aesthetic frontiers and reduces the use of biocides. Moreover, the metabolic processes of photosynthetic biofilms can positively influence human health and life quality in densely populated cities by converting or absorbing pollutants. In the presented research the bioreceptivity of concrete claddings for building facades is engineered to sustain either natural or artificial establishment of microalgae-dominated biofilms. To be able to differentiate between the intrinsic material properties and the climatic boundary conditions, the experimental design in the first step comprised different analyses with model mono- and multi-species biofilms in sterile conditions and a high control of the environmental parameters. Growth and vitality of the algal component of the biofilms has been assessed with Pulse-amplitude modulation (PAM) fluorometry. T2 - 78th RILEM Annual Week & RILEM International Conference on Sustainable Materials & Structures: Meeting the major challenges of the 21st century - SMS 2024 CY - Toulouse, France DA - 25.08.2024 KW - Bioreceptivity KW - Biofilm KW - Weathering KW - Concrete KW - PAM fluorometry KW - Carbonation PY - 2024 AN - OPUS4-62224 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogel, Christian A1 - Urban, Klaus A1 - Ackerhans, C. A1 - Gorbushina, Anna T1 - Analysis of Carbon and Nitrogen from Atmospheric Sources by Bulk Deposition Sampling at various locations in Germany N2 - Atmospheric deposition of particulate matter is an important indicator of air pollution and a significant factor in material surface fouling. The elemental composition of this nutrient-containing dust depends largely on the exposure region and time as well as on climate. Therefore, in this paper we report an analysis of atmospheric pollutions with a self-made low-cost bulk deposition sampler directed at sampling deposition via air transport and rainfall. We used the device in diverse environments - thus comparing an urban region, an area surrounded by forest and an area mainly dominated by agriculture. The total organic carbon (TOC) and total nitrogen (TN) amounts were selected as indicator parameters and analyzed in a biweekly rhythm for three and a half and two years, respectively. The TOC value responded to particulate matter in the urban area, especially significant were the influences of the New Year's firework in urban and pollen in the rural forest area. In contrast, the TN value was more under the influence of the nitrogen emissions in the agriculture-dominated area. However, the TN value did not correlate with the NOx values in the urban area because the atmospheric nitrogen emissions in the city might originate from various emission sources. Summarizing, the TOC and TN values of the self-made low-cost bulk deposition sampler were in good agreement with environmental events of their immediate surrounding. Moreover, the selected containers and sampling procedures are universally applicable to monitor and analyze organic as well as inorganic parameters (e.g. metal ions) of atmospheric deposition. KW - Passive sampling KW - Biomonitoring KW - Air Analysis PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-609373 DO - https://doi.org/10.1016/j.envadv.2024.100583 SN - 2666-7657 VL - 17 SP - 1 EP - 9 PB - Elsevier Ltd. AN - OPUS4-60937 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Taghavi Kalajahi, Sara T1 - Pilot Study of a Laboratory- Based Microbiologically Influenced Corrosion (MIC) Test Using Microbiological Consortia Sampled from the Field N2 - Experts widely agree that the verification of microbiologically influenced corrosion (MIC) require the use of multiple lines of evidence (MLOE), including metallurgical, microbiological, operational/historical and environmental/chemical aspects. Existing standards related to MIC, such as NACE TM0106, TMO212 and TM0194, primarily aim to offer guidance on gathering such evidence. Working Group 5 of Euro-MIC COST action 20130 (Achieving standardization) proposed a laboratory-based approach that directly confirms the capability of the sampled consortium of microorganisms, obtained from the specific field location under investigation, to increase and/or alter the corrosion processes. It is necessary to verify this laboratory approach by conducting it in different laboratories, performed by different scientist. In the current study, the experiments based on the laboratory protocol of WG5 were conducted at Endures’s laboratory using environmental samples (sediment and seawater) from the North Sea. Metal coupons (carbon steel C1010) were exposed to sediment and seawater samples with varying microbial inoculums and controls over 150 days. Microbial identification, corrosion product analysis, and surface morphology assessments were conducted using molecular and microscopy techniques. The results indicate distinct microbial influences, particularly in treatments containing yeast, which fostered heightened anaerobic activity, notably by sulfate-reducing bacteria (SRB). Weight loss measurements and surface analysis revealed elevated corrosion rates and susceptibility to pitting corrosion in microbial inoculum treatments, with yeast presence exacerbating corrosion processes. Elemental analysis confirmed the presence of iron sulfide in corrosion byproducts, affirming SRB activity. The findings emphasize the importance of employing a MLOE approach and investigating pitting corrosion to better understand the impact of microorganisms on metal corrosion in the marine environments. This study contributes to advancing knowledge in the field and developing standardization: the lab-to-field transition for MIC testing. T2 - MIC-STANDS CY - Lisbon, Portugal DA - 24.07.2024 KW - Microbiologically influenced corrosion (MIC), Multiple lines of evidence (MLOE) KW - Marine Corrosion KW - Achieving standardization PY - 2024 AN - OPUS4-61979 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strzelczyk, Rebecca T1 - Constant emitting reference material for emissions test procedures N2 - Since nowadays people spend most of their time indoors, a healthy environment is essential. Volatile organic compounds (VOCs) emitted from furniture and building materials are reported to cause health complaints. Therefore, the usage of low emitting materials will improve the indoor air quality. Quantitative VOC emission testing is usually conducted in emission test chambers under specified controlled conditions as described in DIN 16000-9 and DIN EN 16516. For reasons of quality control/quality assurance (QC/QA) and for a better comparability of test results from different laboratories, suitable emission reference materials (ERM) are needed. Here, it is important to have a homogenous material with known emission rates over a specific time. Different approaches can be found in literature, inter alia polymer films loaded with the target compound to be released again, or a lacquer material to which a VOC mixture is added. After curing of the lacquer, the material can be loaded into a test chamber. Drawback of those approaches are their relatively fast decreasing emission profiles. For QC/QA purposes according to the test standards, VOC sources with constant emission profiles are desirable. The EU-funded research project MetrIAQ “Metrology for the determination of emissions of dangerous substances from building materials into indoor air” is working on a multi-component ERM with an envisaged instability of ≤ 10 % in the emission rate over at least 14 days. Within a doctoral thesis porous materials are impregnated with VOCs. Supercritical CO2 is used as solvent. Thus, the impregnated material does not contain any solvent that may show a measurable amount of emission in the emission test chamber. Furthermore, CO2 has the benefits to have a good availability and low costs. For the selection of porous materials several properties like the pore size, the surface, and the interaction with the components in the atmosphere need to be considered. The impregnation method is optimised while the different porous materials are tested. For the selection of porous materials the pores need to be large enough for the VOC molecules, further influence of the pore size is tested. T2 - Healthy Buildings CY - Aachen, Germany DA - 11.06.2023 KW - VOC KW - Emission KW - Quality assurance KW - Reference material PY - 2023 AN - OPUS4-59842 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -