TY - CONF A1 - Nordholt, Niclas T1 - The disinfectant glutaraldehyde induces antibiotic tolerance underpinned by a Disrupted Cellular State and Heterogenous Regrowth Dynamics N2 - Glutaraldehyde is widely used as a disinfectant and preservative, but little is known about its effects on bacterial susceptibility to antibiotics and the selection of tolerant phenotypes. We found that short-term exposure to sub-inhibitory levels of glutaraldehyde makes E. coli resistant to high doses of bactericidal antibiotics from different classes. This tolerance is associated with delayed, heterogeneous regrowth dynamics and global transcriptome remodeling. We identified over 1200 differentially expressed genes, including those related to antibiotic efflux, metabolic processes, and the cell envelope. The cells entered a disrupted state likely due to the unspecific mode-of-action of glutaraldehyde. Despite this unregulated response, we identified several differentially expressed genes not previously associated with antibiotic tolerance or persistence that induce antibiotic tolerance when overexpressed alone. These findings highlight how the unspecific mode-of-action of disinfectants can make bacteria temporarily resistant to antibiotics. They have implications for settings where disinfectants and antibiotics are used in close proximity, such as hospitals and animal husbandry, and for the selection dynamics of tolerant pheno- and genotypes in fluctuating environments where microorganisms are exposed to these substances, such as sewage systems. A trade-off arises from overcoming the disrupted state as quickly as possible and maintaining antibiotic tolerance. T2 - Molecular Mechanisms in Evolution (GRS) Gordon Research Seminar CY - Easton, Massachusetts, USA DA - 24.06.2023 KW - Glutaraldehyde KW - Biocides KW - Tolerance KW - Bacteria KW - Disinfection KW - Heterogeneity KW - Antibiotics KW - AMR PY - 2023 AN - OPUS4-58032 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gerrits, Ruben A1 - Pokharel, R. A1 - Breitenbach, Romy A1 - Radnik, Jörg A1 - Wirth, R. A1 - Schuessler, J. A. A1 - Benning, L. G. A1 - von Blanckenburg, F. A1 - Gorbushina, Anna A1 - Feldmann, Ines T1 - Olivine weathering by the genetically amenable rock-inhabiting fungus Knufia petricola A95 N2 - In arid sun-exposed environments, rock-inhabiting fungi dominate microbial communities on rock surfaces. Fungi are known to enhance rock weathering, although the exact mechanisms are not completely understood. These natural processes can be simulated by reproducible experimental systems. Particularly attractive are genetically amenable rock-weathering fungi, where certain traits can be knocked-out to identify weathering-relevant functions. Here, we studied the effect of the rock-inhabiting fungus Knufia petricola A95 and its melanin-deficient mutant (ΔKppks) on the weathering of a Fe-bearing olivine. We examined the olivine dissolution kinetics and looked at the olivine-fungus interface. For the former we inoculated olivine powder with the fungus in batch and mixed flow reactors and analysed the medium solution by ICP-OES, for the latter biofilm-covered olivine sections from flow-through reactors were analysed by FIB-TEM. In general olivine dissolution was lower when olivine was incubated without fungi: the abiotic olivine dissolution rates were lowest and the surface of the abiotically reacted olivine sections showed no etching. Various chemical analyses show Fe (oxyhydr)oxide precipitation on top of the abiotically reacted olivine, indicating its role in inhibiting olivine dissolution. Both the wild type (WT) and ΔKppks solubilised and bound significant amounts of Fe released by olivine dissolution. Fe (oxyhydr)oxide precipitation was thus reduced, explaining the enhanced olivine dissolution in their presence. Particularly efficient at preventing Fe precipitation were attached WT cells: the inhibition of olivine dissolution almost completely disappeared. The attachment capacity of the WT is most likely caused by the production of WT-specific extracellular polymeric substances. Our presented experimental systems allowed the precipitation of Fe (oxyhydr)oxides and included a rock-inhabiting fungus and thus simulated weathering processes relevant to natural ecosystems. T2 - ISEB 2019 CY - Potsdam, Germany DA - 23.09.2019 KW - Olivine KW - Weathering KW - Fungus PY - 2019 AN - OPUS4-49585 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas A1 - Schreiber, Frank T1 - Phenotypic heterogeneity in disinfection: sources and consequences for antimicrobial resistance N2 - A summary of projects here at BAM which investigate the influence of phenotypic heterogeneity on the outcome of disinfection and the influence on antimicrobial resistance. This presentation was given in the Theory Seminar of the Quantitative and Theoretical Biology group of Prof. Oliver Ebenhöh at HHU Düsseldorf T2 - Theory Seminar in the Quantitative and Theoretical Biology group at HHU Düsseldorf CY - Düsseldorf, Germany DA - 24.02.2022 KW - Disinfection KW - Biocides KW - Heterogeneity KW - Resistance PY - 2022 AN - OPUS4-54442 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weimann, Karin A1 - Bunzel, Jörg-Michael A1 - Mayer, Felix T1 - Entwicklungen im Gipsrecycling N2 - Gips gehört zu den nachgefragtesten Baustoffen und entsprechend steigt der Gipsverbrauch weltweit schon seit Jahrzehnten an. In Deutschland wird der Gipsbedarf seit vielen Jahren zu einem guten Teil durch REA-Gips, einem Nebenprodukt aus der Abgasreinigung von Kohlekraftwerken, gedeckt. Die weitere Gipsversorgung erfolgt größtenteils durch die Nutzung natürlicher Gipsvorkommen. Ein geringer, aber steigender Anteil an RC-Gips aus dem Baustoffrecycling und die Nutzung synthetischer Gipse aus Nebenprodukten anderer Industriezweige sind ebenfalls zu verzeichnen. Aufgrund der nationalen Klimaschutzziele und der damit verbundenen Abschaltung von Kohlekraftwerken wird das REA-Gipsangebot in den nächsten Jahren jedoch weiter deutlich zurückgehen, so dass andere Gipsquellen erschlossen werden müssen. Abhängig von der Lebensdauer der verwendeten Gipsprodukte im Bausektor ist infolge des in den vergangenen Jahren erfolgten Anstiegs des Gipsverbrauchs auch mit einer Zunahme von Gipsresten in Bau- und Abbruchabfällen zu rechnen. Im Hinblick auf eine bevorstehende Verknappung von Gips wird die Rückgewinnung dieser Gipse aus Bau- und Abbruchabfällen immer wichtiger. Das Recycling von Gipskartonplatten ist mittlerweile eine etablierte Technik und wird bereits seit einigen Jahren in industriellem Maßstab durchgeführt. Außerdem werden neue Verfahren zur Wiederverwertung weiterer Gipsprodukte aus Rück- und Umbaumaßnahmen untersucht. Von besonderem Interesse sind verschiedene Arten von Gipsplatten, da sie gut für selektiven Rückbau geeignet sind. Daher können sie vergleichsweise frei von Verunreinigungen oder Störstoffen zurückgewonnen werden, was für das Gipsrecycling besonders wichtig ist. In dem vom Bundesministerium für Bildung und Forschung geförderten Forschungsprojekt "GipsRec 2.0" werden technische, wirtschaftliche und ökologische Aspekte des Recyclings von Gipsfaserplatten sowie von verschiedenen Synthesegipsen untersucht und bewertet. Die Aufbereitung von Gipsfaserplatten erfolgte im halbtechnischen Maßstab, an verschiedenen potentiellen Ausgangsstoffen für synthetische Gipse wurden Laborversuche durchgeführt. Erfolgversprechende Verfahrenswege werden ökobilanziell bewertet. Ziel dieser Arbeiten ist die Erschließung der Sekundärrohstoffpotenziale von weiteren Quellen für die RC-Gipsproduktion um mit einer Steigerung des Gipsrecyclings die in naher Zukunft durch die Reduktion der REA-Gips-Bereitstellung entstehende Lücke in der Rohstoffversorgung zu verringern. T2 - 21. ibausil 2023 CY - Weimar, Germany DA - 13.09.2023 KW - Baustoffrecycling KW - Sekundärgipse KW - Ökobilanz PY - 2023 AN - OPUS4-60314 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weimann, Karin A1 - Farago, P. A1 - Mayer, Felix T1 - New sources for secondary gypsum N2 - In order to protect natural gypsum deposits and to compensate for the decreasing amount of Flue Gas Desulfurization (FGD) gypsum it is necessary to develop and explore new sources of gypsum. For this purpose, the potentials of different gypsum wastes are investigated in the study “GipsRec 2.0”, funded by the Federal Ministry of Education and Research (Germany). On the one hand, the project worked on a new processing technology for gypsum fiberboards (GFB). While the recycling of gypsum plasterboards has already been carried out on an industrial scale for several years, the recycling of gypsum fiberboards (GFB) has proven to be challenging. Gypsum fiberboards from demolition sites and offcuts from GFB production were used for these investigations. The tests were conducted on a technical scale. Furthermore, various synthetic gypsums are being investigated with regard to their suitability for gypsum production. The analyses are carried out on production residues. In this project, a promising process for gypsum fiberboard recycling could be developed, as well as other waste gypsums are investigated and evaluated with regard to their potential as secondary raw material. In addition, selected process routes are assessed for their environmental impact using a life cycle assessment (LCA) approach. T2 - RILEM - V International Conference Progress of Recycling in the Built Environment CY - Weimar, Germany DA - 10.10.2023 KW - Gypsum recycling KW - Gypsum fiberboards and synthetic gypsum KW - Environmental evaluation PY - 2023 AN - OPUS4-60316 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ronen, A. A1 - Panglisch, S. A1 - Vogel, Christian A1 - Leube, Peter A1 - Ben Efrain, R. A1 - Nir, O. A1 - Chaudhary, M A1 - Futterlieb, M. T1 - Detection, Quantification and Treatment of Per and Polyfluoroalkyl substances (PFAS) in Groundwater N2 - The research project focuses on tackling the detection, measurement, and elimination of per- and polyfluoroalkyl substances (PFAS) from polluted groundwater, with a particular emphasis on addressing short (C4-C7) and ultrashort (C1-C3) chain PFAS. Given the widespread use of PFAS in various products, they are commonly found in groundwater near industrial and military sites in Germany and Israel. Moreover, recent regulations limiting the use of long chain PFAS have led industries to shift towards shorter chain alternatives. Hence, our efforts are geared towards refining detection, quantification, and removal methods for short and ultrashort chain PFAS. In terms of detection, ww are developing passive sampling devices capable of collecting and tracking the temporal distribution of PFAS species in groundwater. This will enable us to analyze contaminations in German and Israeli groundwater using cutting-edge analytical techniques. Additionally, contaminated groundwater will undergo a two-stage treatment process aimed at concentrating the relatively low PFAS concentrations using innovative membrane technologies such as closed-circuit reverse osmosis and mixed matrix composite nanofiltration membrane adsorbers. Subsequently, the streams containing higher PFAS concentrations will be treated through coagulation, with the remaining PFAS being adsorbed onto carbonaceous nanomaterials. The outcome of this research will include the creation of advanced tools for detecting, measuring, and eliminating PFAS from polluted groundwater, while also enhancing our understanding of the scope of these contaminations. T2 - German Israeli Water Technology Status Seminar CY - Koblenz, Germany DA - 18.06.2024 KW - Ground water KW - Per- and Polyfluoroalkyl substances (PFAS) KW - Remediation PY - 2024 AN - OPUS4-60328 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilke, Olaf A1 - Seeger, Stefan T1 - VOC-Emissions from thermoplastic filaments for 3-D-printing N2 - Summary: A screening test for potential emissions of volatile organic compounds (VOC) was run on different thermoplastic filaments used for 3D printing. The method of direct thermal desorption was used to simulate the high temperatures during the 3D printing process and to identify the main compounds emitted from the filaments. A large number of unexpected compounds were detected that might affect the user’s health and have an impact on indoor air chemistry. Introduction: The use of desktop 3D printers is increasing. Compared to other devices with known emissions, e.g. laser printers, there is still a lack of information on possible emissions of VOC and ultrafine particles during operation and the effect on indoor air quality. Most of the commercially available desktop 3D printers operate with a molten polymer deposition. For this process a solid thermoplastic filament is heated in an extrusion nozzle. Most filaments for desktop 3D printers use either acrylonitrile butadiene styrene (ABS) or polylactic acid (PLA) as filament. Alternatives are polyvinyl alcohol (PVA) or polycarbonate (PC). Method: Eight different thermoplastic filaments for 3D printers were analysed by direct thermal desorption followed by GC-MS identification of the emitted substances. Direct thermal desorption was done by desorbing 5 mg of the feedstock for 1 minute at a temperature of 210°C. This is an average temperature for 3D printing with thermoplastic filaments. Results and conclusions: The comparison of the 4 different filament groups showed the highest overall emissions from ABS, followed by PLA, PC and PVA. Filament ABS 2 emitted mainly SVOCs and triphenyl phosphate, the latter has the highest emission for a single compound from all evaluated filaments. Thermoplastic filaments are a new source of VOC emissions due to the high temperatures associated with 3D printing, which can reach up to 270°C. Some of the detected compounds like lactic acid, lactide and bisphenol A have never been described before in the indoor environment. Additionally some of the main substances could not be identified and some others might have the potential to affect the indoor air chemistry. The appearance of some newly detected compounds raises concerns about potential health effects for the users of 3D printers at home. T2 - 20th Conference | Odour and Emissions of Plastic Materials CY - Kassel, Germany DA - 20.03.2018 KW - VOC KW - Emissions KW - 3D printing KW - Thermoplastic filaments PY - 2018 AN - OPUS4-44551 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seeger, Stefan A1 - Osan, J. A1 - Gross, A. A1 - Stabile, L. T1 - AEROMET - Observation of quickly changing element mass concentrations in an ambient aerosol using portable TXRF N2 - Measurements of aerosol particles are vital for enforcing EU air quality regulations to protect human health, and for research on climate change effects. Although metrics such as PM10 and PM2.5 are currently in use, the level of uncertainty of aerosol metrics is too high and the traceability is insufficient. The project AEROMET, which has been started in June 2017 aims at implementing improvements in a) the uncertainty of particle mass, size and number concentration measurements and b) in the characterization of regulated components in airborne particles. Both are demanded by existing networks within the EU as well as by global atmospheric research. On-site measurement campaigns One of the objects is the application of mobile x-ray spectroscopy techniques combined with aerosol sampling techniques for quantifying particle compositions in the field for real time analysis. During two in-field measurement campaigns in Budapest, Hungary in May 2018 and Cassino, Italy in September 2018 the size dependent mass concentrations of specific elements in ambient aerosols were monitored under dynamic conditions. Typically, airborne particles are sampled on filter substrates. During this project new sampling methods with specially designed substrate holders for an in-situ TXRF analysis were developed and applied for the first time. This approach allows a direct time and size resolved analysis without laborious digestion steps and a reduced risk of contamination. Aerosol particles were sampled in a 13-stage DLPI impactor - size range from 0,03 µm to 10 µm - which was equipped with special adapters for acrylic discs of 30 mm diameter, serving as substrates. TXRF analysis was performed on site with the transportable spectrometer S2 PICOFOX (Bruker Nano GmbH) equipped with a Mo X-ray tube and a 30 mm² Silicon Drift Detector (SDD). Excitation conditions were 50 kV, 600 µA, measurement time 1000 s. Quantification was based on internal standardization using 50 ng of Y in solution, which was pipetted into the centre of the discs prior to sampling. At moderate air pollution levels, i.e. PM10 ~ 20 µg/m³, sampling times of less than 2 hours were enough for the detection of elements in different particle size bins. The in-situ approach and the high sensitivity of TXRF enables the observation of rather quick changes in the quantity and distribution of elements in an ambient aerosol on the day of sampling, as the below example from the Cassino field campaign on 11 Sept. 2018 shows: The analysis of the morning and afternoon sampling shifts reveals the occurrence of the elements Fe, Ca and Si in different size bins as well as their significant temporal change in respective mass concentrations over the day while the distributions of several other elements in the aerosol remain unchanged. The validation of these results by backup measurements is planned. T2 - European Aerosol Conference EAC 2019 CY - Gothenburg, Sweden DA - 25.08.2019 KW - TXRF KW - Ambient air KW - Aerosol KW - Cascade impactor KW - Element analysis PY - 2019 AN - OPUS4-49582 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kayser, Y. A1 - Pollakowski-Herrmann, Beatrix A1 - Hönicke, P. A1 - Friese, Carmen A1 - Seeger, Stefan A1 - Cara, E. A1 - Boarino, L. A1 - Gianotti, V. A1 - Laus, M. A1 - Beckhoff, Burkhard T1 - AEROMET – Traceable and reliable chemical analysis of aerosols by X-ray spectrometry N2 - Traceable and reliable chemical element analysis of aerosols by X-ray spectrometry was investigated using aerosol samples from field campaigns which have been measured in the GIXRF-beamline at BESSY. The reference-free XRF approach allows for a traceable analysis of the mass deposition. Traceable quantification by means of XRF can be transfered to benchtop instrumentation used in the laboratory Chemical and dimensional analysis of deposited aerosol allows for a comprehensive analysis of aerosols, e.g. for toxicity assessment and determination of the source The folowing elements could be identified and quantified in the field samples: Al, Si, P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Y, W, Pb. T2 - European Aerosol Conference EAC 2019 CY - Gothenburg, Sweden DA - 25.08.2019 KW - TXRF KW - Element mass concetration KW - Ambient aerosol KW - Cascade impactor PY - 2019 AN - OPUS4-49583 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bucar, K. A1 - Zitnik, M. A1 - Stabile, L. A1 - Ozan, J. A1 - Seeger, Stefan T1 - Performance of a Sharp GP2Y low-cost aerosol PM sensor N2 - Simple particulate matter sensors are gaining popularity due to their low price, easy handling and good temporal resolution. In this presentation, we report on the performance of a Sharp optical PM sensor GP2Y1010AU0F, which costs less than 15 €. The sensor is built around an infrared emitting diode (ILED) and a phototransistor detecting the light scattered from the aerosol particle. An electronic circuit shapes the detected light in a pulsed signal. The manufacturer advises sampling the output signal 280 microseconds after the ILED pulse. The measured output voltage is an indicator of dust concentration. We have built two identical simple PM monitoring devices using Raspberry Pi 3 computer interfacing the PM sensor with Microchip’s MCP3002 ADC via SPI. The ADC is capable of more than 100 ksamples/s at 10-bit resolution. The Rpi3 was pulsing the sensor at 10Hz, digitizing and saving the data and sending the results wirelessly. Sensor’s output pulse shape was sampled with 10 microsecond time steps and saved, thus making offline analysis possible. A time jitter of output pulses can be observed and suggests a peak fitting as a better approach to the signal readout compared to the single sampling at a fixed time after pulse triggering We compared both methods. T2 - European Aerosol Coference EAC 2019 CY - Gothenburg, Sweden DA - 25.08.2019 KW - Aerosol KW - Low cost aerosol PM sensor KW - PM PY - 2019 AN - OPUS4-49581 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -