Fakultät Naturwissenschaften

Permanent URI for this communityhttps://hohpublica.uni-hohenheim.de/handle/123456789/1

Biologie, Ernährungs-wissenschaften und Lebensmittelwissenschaften sind die Schwerpunkte der Fakultät. Die Forschung befasst sich mit Schlüsselthemen der Life Sciences.

Homepage: https://natur.uni-hohenheim.de/

Browse

Browsing Fakultät Naturwissenschaften by Sustainable Development Goals "15"

Type the first few letters and click on the Browse button
Now showing 1 - 3 of 3
  • Thumbnail Image
    Publication
    Decoding the geography of natural TBEV microfoci in German: a geostatistical approach based on land-use patterns and climatological conditions
    (2022) Borde, Johannes P.; Glaser, Rüdiger; Braun, Klaus; Riach, Nils; Hologa, Rafael; Kaier, Klaus; Chitimia-Dobler, Lidia; Dobler, Gerhard
    Background: Tickborne-encephalitis (TBE) is a potentially life-threating neurological disease that is mainly transmitted by ticks. The goal of the present study is to analyze the potential uniform environmental patterns of the identified TBEV microfoci in Germany. The results are used to calculate probabilities for the present distribution of TBEV microfoci in Germany based on a geostatistical model. Methods: We aim to consider the specification of environmental characteristics of locations of TBEV microfoci detected in Germany using open access epidemiological, geographical and climatological data sources. We use a two-step geostatistical approach, where in a first step, the characteristics of a broad set of environmental variables between the 56 TBEV microfoci and a control or comparator set of 3575 sampling points covering Germany are compared using Fisher’s Exact Test. In the second step, we select the most important variables, which are then used in a MaxEnt distribution model to calculate a high resolution (400 × 400 m) probability map for the presence of TBEV covering the entire area of Germany. Results: The findings from the MaxEnt prediction model indicate that multi annual actual evapotranspiration (27.0%) and multi annual hot days (22.5%) have the highest contribution to our model. These two variables are followed by four additional variables with a lower, but still important, explanatory influence: Land cover classes (19.6%), multi annual minimum air temperature (14.9%), multi annual sunshine duration (9.0%), and distance to coniferous and mixed forest border (7.0%). Conclusions: Our findings are based on defined TBEV microfoci with known histories of infection and the repeated confirmation of the virus in the last years, resulting in an in-depth high-resolution model/map of TBEV microfoci in Germany. Multi annual actual evapotranspiration (27%) and multi annual hot days (22.5%) have the most explanatory power in our model. The results may be used to tailor specific regional preventive measures and investigations.
  • Thumbnail Image
    Publication
    Disc mower versus bar mower: Evaluation of the direct effects of two common mowing techniques on the grassland arthropod fauna
    (2025) von Berg, Lea; Frank, Jonas; Betz, Oliver; Steidle, Johannes L. M.; Böttinger, Stefan; Sann, Manuela; von Berg, Lea; Evolutionary Biology of Invertebrates, Institute for Evolution and Ecology, University of Tübingen, Tübingen, Germany; Frank, Jonas; Fundamentals of Agricultural Engineering, Institute for Agricultural Engineering, University of Hohenheim, Stuttgart, Germany; Betz, Oliver; Evolutionary Biology of Invertebrates, Institute for Evolution and Ecology, University of Tübingen, Tübingen, Germany; Steidle, Johannes L. M.; Chemical Ecology, Institute for Biology, University of Hohenheim, Stuttgart, Germany; Böttinger, Stefan; Fundamentals of Agricultural Engineering, Institute for Agricultural Engineering, University of Hohenheim, Stuttgart, Germany; Sann, Manuela; Chemical Ecology, Institute for Biology, University of Hohenheim, Stuttgart, Germany
    1. In Central Europe, species‐rich grasslands are threatened by intensive agriculture with frequent mowing, contributing to the reduction of arthropods such as insects and spiders. However, comprehensive and standardised studies on the direct effects of the two most agriculturally relevant mowing techniques, e.g., double‐blade bar mower versus disc mower, are lacking. 2. In a 2‐year experiment, we have investigated the direct effect of mowing on eight abundant arthropod groups in grassland, covering two seasonal mowing events in both years, using a randomised block design. We compared (a) an unmown control, (b) a double‐blade bar mower and (c) a disc mower. 3. For most of the taxonomic groups studied, a significantly lower number of individuals was found in the experimental plots immediately after mowing, regardless of the mowing technique, compared to an unmown control. This was not the case for Orthoptera and Coleoptera, which did not show a significant reduction in the number of individuals for both mowing techniques (Orthoptera) or only for the double‐blade bar mower (Coleoptera). 4. Between both mowing techniques, no significant differences were found for all taxonomic groups investigated. 5. Synthesis and applications: Our findings suggest that mowing in general has a negative impact on abundant arthropod groups in grassland, regardless of the method used. Tractor‐driven double‐blade bar mowers do not seem to be a truly insect‐friendly alternative to a conventional disc mower. Other factors such as cutting height and mowing regimes should be seriously considered to protect spiders and insects from the negative effects of mowing. In addition, we strongly recommend the maintenance of unmown refugia. Insects and spiders that are spared by mowing can take refuge in these unmown areas to avoid subsequent harvesting and thermally unfavourable conditions that arise on mown areas. Further, unmown refugia are basic habitat structures for a subsequent recolonisation of mown areas once the flora has recovered.
  • Thumbnail Image
    Publication
    The low mutational flexibility of the EPSP synthase in Bacillus subtilis is due to a higher demand for shikimate pathway intermediates
    (2023) Schwedt, Inge; Schöne, Kerstin; Eckert, Maike; Pizzinato, Manon; Winkler, Laura; Knotkova, Barbora; Richts, Björn; Hau, Jann-Louis; Steuber, Julia; Mireles, Raul; Noda‐Garcia, Lianet; Fritz, Günter; Mittelstädt, Carolin; Hertel, Robert; Commichau, Fabian M.
    Glyphosate (GS) inhibits the 5-enolpyruvyl-shikimate-3-phosphate (EPSP) synthase that is required for aromatic amino acid, folate and quinone biosynthesis in Bacillus subtilis and Escherichia coli. The inhibition of the EPSP synthase by GS depletes the cell of these metabolites, resulting in cell death. Here, we show that like the laboratory B. subtilis strains also environmental and undomesticated isolates adapt to GS by reducing herbicide uptake. Although B. subtilis possesses a GS-insensitive EPSP synthase, the enzyme is strongly inhibited by GS in the native environment. Moreover, the B. subtilis EPSP synthase mutant was only viable in rich medium containing menaquinone, indicating that the bacteria require a catalytically efficient EPSP synthase under nutrient-poor conditions. The dependency of B. subtilis on the EPSP synthase probably limits its evolvability. In contrast, E. coli rapidly acquires GS resistance by target modification. However, the evolution of a GS-resistant EPSP synthase under non-selective growth conditions indicates that GS resistance causes fitness costs. Therefore, in both model organisms, the proper function of the EPSP synthase is critical for the cellular viability. This study also revealed that the uptake systems for folate precursors, phenylalanine and tyrosine need to be identified and characterized in B. subtilis.