TY - CONF A1 - Kjaervik, Marit A1 - Dietrich, P. A1 - Thissen, A. A1 - Schwibbert, Karin A1 - Unger, Wolfgang T1 - Depth-dependent analysis of model biofilms by combining laboratory- and synchrotron-based X-ray photoelectron spectroscopy N2 - Synchrotron XPS in the soft-X-ray regime is suitable for the detection of light elements commonly found in biological samples. Various model systems of biofilms have been developed and characterised at synchrotron- and lab-based facilities. By obtaining the chemical composition at various information depths, the vertical distribution of iodine in an artificial biofilm have been determined. T2 - Tenth Joint BER II and BESSY II User Meeting CY - Berlin, Germany DA - 05.12.2018 KW - Biofilms KW - HAXPES KW - XPS KW - Iodine KW - Synchrotron-XPS PY - 2018 AN - OPUS4-46929 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Huang, Y.-L. A1 - Zheng, A1 - Zhang, A1 - Lu, A1 - Wang, A1 - Kunte, Hans-Jörg A1 - Sand, W. T1 - Forecast on Long Term Chemical Environment Evolution on Surface of Nuclear Waste Container N2 - Surface environment changes of nuclear waste container, mainly including oxygen contents, buffer pore water components and pH under the conditions of “borehole” type and “In-floor” type with bentonite buffer/backfill and concrete buffer were summarized. This summarization provides a basic corrosion environment reference for the corrosion evolution re- search of high-level radioactive waste disposal repository in our country. KW - Corrosion evolution KW - Nuclear waste KW - Disposal repository KW - Corrosion environment PY - 2018 DO - https://doi.org/10.7643/ issn.1672-9242.2018.10.017 SN - 1672-9242 VL - 15 IS - 10 SP - 103 EP - 108 PB - Zhongguo Bingqi Gongye di-wujiu Yanjiusuo CY - Chongqing AN - OPUS4-46952 LA - zho AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Huang, A1 - Zheng, A1 - Zhang, A1 - Lu, A1 - Wang, A1 - Kunte, Hans-Jörg A1 - Sand, W. T1 - Long Term Temperature and Humidity Evolution Forecast in Near Field of Nuclear Waste Container N2 - The paper aims to simulate the corrosion environment of nuclear waste containers at different geological disposal periods to obtain temperature and humidity information at the interface between the container and the surrounding environment. The simulated data and calculation results of long term temperature evolution at the surface of nuclear waste (HLW) containers from some typical nuclear countries about the safety disposition were reviewed. Combining different burial patterns, this paper speculated the long term temperature evolution rule for China. According to the study about saturation variation of buffer/backfill material at home and abroad, the humidity evolution of bentonite at the surface of HLW containers was specu- lated. The study showed that the temperature of the container surface increased rapidly at the beginning, and gradually decreased after the climax. For safety reasons, the maximum temperature was designed below 100°C. The saturation of bentonite was af- fected by the mutual influences of the heat released by nuclear waste decay and the infiltration of groundwater. It was dominated by the released heat in the early stage, and later was influenced greatly by the infiltration of groundwater. It is generally believed that the water content at the surface of the container will increase obviously in about 3 years, and will be saturated in about 10 years. The prediction of long-term temperature and humidity evolution will lay a foundation for study of corrosion evolution of nuclear waste containers in China. KW - Corrosion evolution KW - Nuclear waste KW - Disposal repository KW - Temperature and humidity PY - 2018 SN - 1672-9242 VL - 15 IS - 10 SP - 109 EP - 113 PB - Zhongguo Bingqi Gongye di-wujiu Yanjiusuo CY - Chongqing AN - OPUS4-46953 LA - zho AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Plarre, Rüdiger T1 - Ungebetene Gäste im Museum – Biologie von Kleidermotte, Holzwurm und Co. N2 - Gemeiner Nagekäfer und Kleidermotte sind unerwünscht im Museum. Kulturgüter mit Anteilen von Holz, Federn, Wolle, Haare, etc. wie ethnologische oder naturkundliche Sammlungsstücke, aber auch Bilderahmen oder Freilichtmuseen werden von ihnen gerne besucht. Dabei sind es die Jugendstadien (Larven) dieser Insekten, die sich von ungeschützten Exponaten oder Depotstücken, die diese natürlichen Materialien enthalten, ernähren. Die Entwicklung der Larven findet verborgen im Inneren der Materialien statt. Die geflügelten erwachsenen Formen, die sich im freien Raum bewegen, sich fortpflanzen und den Neubefall herbeiführen, treten saisonal sehr begrenzt auf. Eine frühzeitige Detektion der Schädlinge, als erwachsenes Insekt oder als Larve, ist dadurch erschwert. Es gilt folglich deren Präsenz und erste Anzeichen eines Befalls zuverlässig und vor allem frühzeitig feststellen zu können, um geeignete Maßnahmen zum Schutz des Kulturgutes einzuleiten. Neben dem Wissen um die Materialeigenschaften des Kulturgutes sind umfängliche Kenntnis über die Biologie der Schädlinge, zu ihren grundsätzlichen Lebensansprüchen und insbesondere zum Verhalten, das zum Neubefall führt, wichtig. Die Larvenstadien von Holz- und Textilschädlingen zeichnen sich durch hohe Toleranzen gegenüber extremen Temperaturen und Luftfeuchten aus. Für sie ungünstige Bedingungen können sie sehr lange in Ruhephasen überdauern. Nicht erkannter, versteckter Befall von Materialien sind häufige Infektionsquellen für Neubefall von Sammlungen. Verborgene natürliche Befallsquellen im eigenen Museumssystem spielen bei Neubefall von Exponaten eine größere Rolle als der Zuflug von Schadinsekten aus Reservoiren von außen. Der Vortrag stellt beispielhaft Lebenszyklen relevanter Schädlingsarten vor und zeigt Möglichkeiten gezielter Interventionen auf, die in ein IPM Konzept einfließen können. Dies umfasst vorbeugende Maßnahmen wie geeignetes Klima in Ausstellungs- und Lagerräumen, das sogenannte Monitorring sowie eine konsequente Quarantäne bis hin zu physikalischen, biologischen oder chemischen Bekämpfungsmaßnahmen. T2 - AK Konservierung/Restaurierung Doerner Institut CY - Munich, Germany DA - 06.12.2018 KW - IPM KW - Kulturgut KW - Hausbock KW - Kleidermotte PY - 2018 AN - OPUS4-46962 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas A1 - Lewerenz, Dominique A1 - Schmidt, Selina A1 - Schreiber, Frank T1 - Heterogeneity in the bacterial response to disinfection and its impact on antibiotic tolerance and resistance N2 - The global rise of antibiotic resistance has made the proper use of disinfectants more important than ever. Their application in clinical l settings is an integral part of antibiotics stewardship by preventing the occurrence and spread of infections. However, improper use of disinfectants also harbours the risk for the evolution of tolerance and resistance to disinfectants, but also to antibiotics. It is therefore crucial to understand whether and how bacteria can survive chemical disinfection and which conditions facilitate the evolution of tolerance and resistance. Here, we study the heterogeneity in the response of isogenic E. coli populations exposed to different levels of commonly used disinfectants. At concentrations below the minimal inhibitory concentration (MIC), we find that certain disinfectants induce prolonged lag times in individual cells, a phenotype that has been associated with persistence against antibiotics. At concentrations above the MIC, we find heterogeneous killing for a range of the tested substances. Interestingly, for the three cationic surfactants that were tested, we find kill kinetics revealing the presence of a tolerant subpopulation that can withstand disinfection longer than most of the population. We will present results from an ongoing evolution experiment in which we test the potential for evolution of population-wide tolerance and resistance through intermittent exposure to lethal doses of a cationic surfactant. T2 - New Approaches and Concepts in Microbiology CY - Heidelberg, Germany DA - 10.07.2019 KW - Persistence KW - Biocides KW - Resistance KW - heterogeneity KW - Bacteria PY - 2019 AN - OPUS4-48524 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koerdt, Andrea A1 - An, Biwen Annie A1 - Kleinbub, Sherin A1 - Herrmann, Annett T1 - Investigation of methanogen-induced microbiologically influenced corrosion (Mi-MIC) using simulated marine environments under flowing conditions N2 - Microbiologically influenced corrosion (MIC) of iron is usually attributed to sulfate-reducing microorganisms (SRM) in oil and gas facilities. SRM act upon the metal by the re-activeness of hydrogen sulfide (HS-), and by withdrawal of the available electrons in electrical contact with the metal (EMIC). Methanogenic archaea (MA) can also cause MIC (Mi-MIC). Several MAs were identified to be corrosive by using elemental iron as the sole electron donor for methanogenesis, including Methanobacterium­-affliated IM1 and Methanococcus maripaludis Mic1c10. Currently, low corrosion rates were reported for MA, possibly due to the formation of siderite (4Fe + 5HCO3- + 5H+ ® 4FeCO3 + CH4 + 3H2O). Since MA do not produce HS-, withdrawal of electrons may be their main corrosive mechanism; however, mechanistic details and kinetics of the overall process are poorly understood. To investigate the corrosion potential of MA, we studied the EMIC methanogenic strains (IM1 and Mic1c10) individually or part of a syntrophic co-culture with SRM. Corrosion studies were conducted using an in-house developed flow-through system to simulate fluctuating environmental conditions. Results indicate that the rates of iron corrosion by MA (up to 0.4 mm/yr) are higher to that caused by the marine SRM Desulfovibrio alaskensis (0.15 mm/yr) and the co-culture (0.1 mm/yr). Scanning electron microscopy (SEM) images of the metal incubated with MA showed severe pitting corrosion. Genomic analysis of the EMIC MA was conducted to provide an insight on the possible cellular mechanisms that could be involved. Furthermore, low concentrations of MA-targeting biocides will be applied to EMIC MA in static and flow conditions to gain insights for possible mitigation strategies. Such knowledge and deeper understanding also from an electrokinetic point of view may not only provide further models in microbial electrophysiology, but also contribute to mitigation strategies in MIC. T2 - 7th International Symposium on Applied Microbiology and Molecular Biology in Oil Systems CY - Halifax, Canada DA - 18.06.2019 KW - MIC KW - Microbiologically influenced corrosion KW - Methanogens KW - SRB KW - Corrosion KW - Metalls PY - 2019 AN - OPUS4-48392 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koerdt, Andrea A1 - An, Biwen Annie A1 - Kleinbub, Sherin T1 - Investigation of methanogen-induced microbiologically influenced corrosion (Mi-MIC) using simulated marine environments under flowing conditions N2 - Microbially influenced corrosion (MIC) of iron is usually attributed to sulfate-reducing microorganisms (SRM) which act upon the metal by the reactiveness of hydrogen sulfide, and by withdrawal of the available electrons in electrical contact with the metal. Methanogenic archaea can also cause MIC by directly withdrawing electrons from the iron surface for methanogenesis. However, the mechanistic details and kinetics of the overall process are poorly understood. Precipitation of siderite, a by-product of methanogenesis, (4Fe + 5HCO3 + 5H+  4FeCO3 + CH4 + 3H2O) can lead to an insulating layer on the metal surface and lower the corrosion rate. Still, the extent of FeCO3 precipitation may be significantly influenced by environmental conditions such as pH and advective processes. T2 - Dechema CY - Frankfurt a. M., Germany DA - 13.05.2019 KW - MIC KW - Corrosion KW - Methanogens KW - Corrosion product PY - 2019 AN - OPUS4-47982 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kjaervik, Marit A1 - Dietrich, P. A1 - Thissen, A. A1 - Schwibbert, Karin A1 - Brown, J. A1 - Hardie, K. A1 - Unger, Wolfgang T1 - Model systems and sample preparation for surface characterisation of bacteria and biofilms by near-ambient pressure XPS N2 - Bacterial samples are typically freeze dried or cryo-prepared prior to XPS analysis to allow for measurements in ultra-high vacuum (UHV). The sample environment in the near-ambient pressure (NAP) XPS instrument EnviroESCA allows for measurements in up to 15 mbar water vapor, thus, sample preparation is no longer restricted to UHV-compatible techniques. For instance, biofilms grown in medium can be transferred directly from the medium to the measurements chamber, maintaining a humid environment throughout the measurements. Considering the complexity of bacterial samples, sample preparation must be carefully considered in order to obtain meaningful and reproducible results. In this talk, various strategies for sample preparation of bacteria and biofilms for NAP-XPS measurements will be discussed. Model systems of planktonic bacteria, artificial biofilms resembling the exopolysaccharide matrix and biofilms have been characterised in various conditions. The stability and homogeneity of the samples was assessed by monitoring the C1s core level peak at different sample locations. The quality of the XPS-spectra is also influenced by the gas environment, which will be exemplified by core level spectra of P. Fluorescens acquired in air, water vapor and ultra-high vacuum. T2 - 18th European conference on applications of surface and interface analysis (ECASIA) CY - Dresden, Germany DA - 15.09.2019 KW - NAP-XPS KW - Biofilms KW - Bacteria KW - E. coli KW - XPS PY - 2019 AN - OPUS4-49189 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - An, Biwen Annie A1 - Koerdt, Andrea T1 - Investigating and modelling MIC using in-house developed flow system (Hi-Tension) N2 - Microbiologically influenced corrosion is a multidisciplinary research area. To develop successful mitigation strategies, expertise from the industry and research institutes are essential. In Department 4.1, we developed an innovative laboratory flow model (Hi-Tension) that allows effective monitoring of MIC under both standard and non-standard conditions. The flow model allows flexibility with material selection, flow rates, temperature and other environmental parameters changes. Furthermore, the flow model allows integration of electrochemical measurements using microsensors, providing a comprehensive view of corrosion at the biofilm level. Currently, initial results indicate corrosion in the flow model is significantly higher than that of standard laboratory set ups, i.e. static incubations, particularly for methane-producing microorganisms. T2 - Departmental Meeting with Helmotz Dresden CY - BAM, Berlin, Germany DA - 04.11.2019 KW - MIC KW - Corrosion KW - FIB/SEM KW - Corrosion products KW - Hi-Tension KW - Flow Model KW - Modelling PY - 2019 AN - OPUS4-49417 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - An, Biwen Annie A1 - Koerdt, Andrea A1 - Kleinbub, Sherin T1 - Microbial modelling of sulfate-reducing bacteria (SRB) and methanogenic archaea (ME) using iron N2 - Sulfate reducing bacteria (SRB) and methanogenic archaea (MA) are commonly found in the oil and gas environments. The formation of hydrogen sulfide (HS-) is particularly concerning for the petroleum industry due to its corrosiveness. However, the activities of SRB are limited to the concentration of sulfate present in the environment, whereas methanogens can utilize substrates such as H¬2 for methanogenesis. MA is commonly found in sulfate-free environments, such as deep sediments, and are known to form interspecies electron transfer relationships with SRB. Recently, SRB and MA capable of microbiologically influenced corrosion (MIC) by using elemental iron as a direct electron source (EMIC) have gained increased attention. On the iron surface, EMIC-SRB can outcompete EMIC-MA in the presence of sulfate, but this changes as sulfate depletes. The formation of FeS on the metal surface can be further utilized by MA for methanogenesis as it provides a conductive path. However, the possible kinetics involved of the overall process are currently unknown. We obtained a co-culture of EMIC-SRB and EMIC-MA to investigate the growth rates and electrical potential changes under different environmental conditions, including changes in pH, temperature and salinity. Results indicate that under neutral conditions and using iron as the sole substrate, methane production (up to 5 mM) starts after sulfate was depleted. Electrochemical measurements will be conducted on the co-culture under different conditions to determine the changes in the electrical potential in correlation with the sulfate and methane concentration. Fluorescence and electron microscope images of the biofilm structure will be used to visualize cell distribution and morphology. This study embarks the first step of understanding the relationship between EMIC-SRB and EMIC-MA. Such knowledge is important for the field of microbial electrophysiology and can be further explored for industrial applications. T2 - 7th International Symposium on Applied Microbiology and Molecular Biology in Oil Systems (ISMOS-7) CY - Halifax, Canada DA - 18.06.2019 KW - MIC KW - Corrosion KW - FIB/SEM KW - Corrosion products KW - Bacteria KW - Archaea KW - Iron PY - 2019 AN - OPUS4-49420 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -