TY - JOUR A1 - Tauber, J. P. A1 - McMahon, Dino Peter A1 - Ryabov, E. V. A1 - Kunat, M. A1 - Ptaszynska, A. A. A1 - Evans, J. D. T1 - Honeybee intestines retain low yeast titers, but no bacterial mutualists, at emergence N2 - Honeybee symbionts, predominantly bacteria, play important roles in honeybee health, nutrition, and pathogen protection, thereby supporting colony health. On the other hand, fungi are often considered indicators of poor bee health, and honeybee microbiome studies generally exclude fungi and yeasts. We hypothesized that yeasts may be an important aspect of early honeybee biology, and if yeasts provide a mutual benefit to their hosts, then honeybees could provide a refuge during metamorphosis to ensure the presence of yeasts at emergence. We surveyed for yeast and fungi during pupal development and metamorphosis in worker bees using fungal-specific quantitative polymerase chain reaction (qPCR), next-generation sequencing, and standard microbiological culturing. On the basis of yeast presence in three distinct apiaries and multiple developmental stages, we conclude that yeasts can survive through metamorphosis and in naïve worker bees, albeit at relatively low levels. In comparison, known bacterial mutualists, like Gilliamella and Snodgrassella, were generally not found in pre-eclosed adult bees. Whether yeasts are actively retained as an important part of the bee microbiota or are passively propagating in the colony remains unknown. Our demonstration of the constancy of yeasts throughout development provides a framework to further understand the honeybee microbiota. KW - Fungi KW - Honeybee KW - Microbiota KW - Yeast PY - 2022 DO - https://doi.org/10.1002/yea.3665 SN - 1097-0061 VL - 39 IS - 1-2 SP - 95 EP - 107 PB - John Wiley & Sons Ltd. CY - London, UK AN - OPUS4-53892 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sieksmeyer, T. A1 - He, S. A1 - Esparza Mora, Margy Alejandra A1 - Jiang, S. A1 - Petrasiunaite, V. A1 - Kuropka, B. A1 - Banasiak, Ronald A1 - Julseth, M. J. A1 - Weise, C. A1 - Johnston, P. R. A1 - Rodriguez-Rojas, A. A1 - McMahon, Dino Peter T1 - Eating in a losing cause: Limited benefit of modifed macronutrient consumption following infection in the oriental cockroach Blatta orientalis N2 - Background: Host–pathogen interactions can lead to dramatic changes in host feeding behaviour. One aspect of this includes self-medication, where infected individuals consume substances such as toxins or alter their macronutrient consumption to enhance immune competence. Another widely adopted animal response to infection is illness-induced anorexia, which is thought to assist host immunity directly or by limiting the nutritional resources available to pathogens. Here, we recorded macronutrient preferences of the global pest cockroach, Blatta orientalis to investigate how shifts in host macronutrient dietary preference and quantity of carbohydrate (C) and protein (P) interact with immunity following bacterial infection. Results: We fnd that B. orientalis avoids diets enriched for P under normal conditions, and that high P diets reduce cockroach survival in the long term. However, following bacterial challenge, cockroaches signifcantly reduced their overall nutrient intake, particularly of carbohydrates, and increased the relative ratio of protein (P:C) consumed. Surprisingly, these behavioural shifts had a limited efect on cockroach immunity and survival, with minor changes to immune protein abundance and antimicrobial activity between individuals placed on diferent diets, regardless of infection status. Conclusions: We show that cockroach feeding behaviour can be modulated by a pathogen, resulting in an illness-induced anorexia-like feeding response and a shift from a C-enriched to a more P:C equal diet. However, our results also indicate that such responses do not provide signifcant immune protection in B. orientalis, suggesting that the host’s dietary shift might also result from random rather than directed behaviour. The lack of an apparent beneft of the shift in feeding behaviour highlights a possible reduced importance of diet in immune regulation in these invasive animals, although further investigations employing pathogens with alternative infection strategies are warranted. KW - Animal immune system KW - A key interface KW - Host and symbiont ecology KW - Behavioural mechanisms KW - Biotic environment PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-550022 DO - https://doi.org/10.1186/s12862-022-02007-8 SN - 2730-7182 VL - 22 IS - 1 SP - 1 EP - 14 PB - Springer Nature CY - London, UK AN - OPUS4-55002 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fürst, Richard A1 - Häßler, Dustin A1 - Peter, A. A1 - Rohleder, R. A1 - Hothan, Sascha T1 - European test standard intumescent coatings applied to steel tension bars with solid section N2 - Intumescent coatings are used in civil engineering to improve the fire resistance of steel constructions. Due to the thin coating thickness and the profile-following application, the architectural appearance of the steel structure can be preserved. EN 13381-8 provides regulations to determine the contribution to the fire resistance of intumescent coatings applied to steel beams and columns. The scope of this standard excludes tension members and steel members with solid sections. For products that have already been successfully tested and assessed on beams and columns, EN 13381-10 offers the possibility based on unloaded fire tests to extend the scope of application of intumescent coatings to tension bars with solid sections. This approach contradicts the national safety level in Germany, where mechanically loaded testing is mandatory. Therefore, a new part of the test standard series EN 13381 is currently developed to enable the application of intumescent coatings on steel tension bars with solid section based on mechanically loaded fire tests. BAM has already carried out numerous fire tests on loaded steel tension members with intumescent coatings. Currently, in the BAM research project FIRESTEMIC, the influence of the steel bar orientation and the profile type on the thermal performance of intumescent coatings are investigated. Both questions concerning the thermal protection ability of intumescent coatings were analysed based on three different test sets, which were carried out in the tension furnace (Fig. 1a). The fire exposure corresponds to the standard temperature-time curve according to EN 1363-1. This paper summarises the main findings from the fire tests conducted in the FIRESTEMIC project. The results serve as an experimental background for the proposal of the new standard. Regarding the bar orientation, a new test setup was developed and proposed for the new standard. The two tested commercial water-based intumescent coatings with applied dry film thickness from 1.5 mm to 2.5 mm showed only a slight dependence on the bar orientation. In terms of the steel profile type, circular and rectangular solid sections with identical section factor and applied dry film thickness were tested. It was observed that the circular solid bars with diameter 30 mm heat up faster compared to the solid rectangular bars with dimension 30×30 mm (Fig. 1b). Also at larger steel bars, i.e. diameter 40 mm and dimension 40×40 mm, the same trend occurred. Thus, it is recommended for the new test standard to allow a transfer of the test results from circular to rectangular solid sections. In addition, the paper will describe and explain the test and assessment procedure proposed for the newly developed standard. T2 - 8th Symposium Structural Fire Engineering CY - Brunswick, Germany DA - 13.09.2022 KW - Fire test KW - Steel KW - Tension member KW - Intumescent coating KW - Test standard PY - 2022 SP - 1 EP - 14 PB - TU Braunschweig CY - Braunschweig AN - OPUS4-55703 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -