Die räumliche Verteilung und funktionellen Eigenschaften mikrobieller Gemeinschaften in Agrarunterböden

Subsoil microbial communities are distinct from those in topsoil. Important microbial hotspots in subsoil, such as drilosphere and rhizosphere, arise from vertical biopores and contribute to spatial heterogeneity of prokaryotic phyla and an increased nutrient turnover in deeper soil horizons. The significance of subsoil microorganisms for plant nutrition and health is discussed.Die mikrobiellen Gemeinschaften in Unterböden unterscheiden sich grundlegend von denen in Oberböden. Bedeutende mikrobielle Hotspots in Unterböden, wie zum Beispiel Drilosphäre und Rhizosphäre, entstehen durch vertikale Bioporen und tragen zur räumlichen Heterogenität prokaryotischer Phyla und einem erhöhten Nährstoffumsatz in tieferen Bodenhorizonten bei. Die Signifikanz von Mikroorganismen im Unterboden für die Pflanzenernährung und -gesundheit wird herausgestellt

Microbial carbon turnover in the detritusphere

Microbial decomposition processes at the soil-litter interface involves a complex food web including fungi, bacteria, and archaea that compete for the organic matter. During the decomposition, the nutrient quantity and quality changes as well as the microbial community composition. It is still a challenge to identify and quantify active microbial species in concurrency with their absolute contribution to the carbon (C) turnover. In the frame of the DFG-Project (FOR 918) “Carbon flow in belowground food webs assessed by isotope tracers“ we determined the C flow and turnover of differently aged maize litter in bacteria and fungi of an arable soil. A microcosm experiment was set up with C-13-labeled and unlabeled maize litter on top of soil cores. A reciprocal transplantation of the labeled litter on soil cores with unlabeled litter allowed us to follow the C flow into different microbial groups at the early (0-4d), intermediate (4-12d) and late stage (28-36d) of litter decomposition. We analyzed microbial CO2 respiration, microbial biomass and PLFA pattern in the top 3 mm of the soil cores. To identify and quantify microbial species feeding on the substrate and to assess their degree of C-13 assimilation, DNA stable isotope probing followed by gene-targeted sequencing of bacteria and fungi are currently performed on the soil metagenome. We expected specific microbial communities (copio- and oligotrophic) involved in maize litter decomposition at the different stages of litter decay. During the initial days of the experiment, up to 17% of the CO2-C was maize-derived C. The C-13 content in the CO2 decreased with continuous decomposition of the litter. The highest absolute amount of maize-derived C was found in gram-positive bacteria in the early stage of litter decomposition. For fungi, the highest maize C incorporation was in the intermediate stage of litter decomposition. We calculated a faster C turnover in the fungal biomass than in the bacterial biomass for all three decomposition stages. But during the later stage of litter decomposition, maize-derived C was less utilized by both bacteria and fungi. These results will be concluded by the quantitative DNA-SIP method to provide a species-resolved contribution to the C turnover in the microbial food web at different decomposition stages in the detritusphere

Breaching principles of the rule of law in constitutional system of Poland between 2015-2021

Práce přibližuje problematiku ústavní krize v Polsku, která vznikla v roce 2015 a jejím předmětem je kromě reforem justice především systémové porušování principu právního státu. Obsahem je pojednání o jednotlivých přijímaných změnách, především v zákonech o Ústavním soudu, Nejvyšším soudu a Národní soudcovské radě. Dále se práce zaměřuje na kritiku ze strany EU, resp. SDEU, která má za cíl narovnat vadný právní stav.ObhájenoThe thesis presents the issue of the constitutional crisis in Poland, which emerged in 2015 and whose subject, in addition to judicial reforms, is mainly the systemic violation of the rule of law. The content is a discussion of individual changes adopted, especially in the laws on the Constitutional Court, the Supreme Court and the National Judicial Council. Furthermore, the work focuses on the criticism from the EU or the CJEU, which aims to straighten out the defective legal situation

Breaching principles of the rule of law in constitutional system of Poland between 2015-2021

Práce přibližuje problematiku ústavní krize v Polsku, která vznikla v roce 2015 a jejím předmětem je kromě reforem justice především systémové porušování principu právního státu. Obsahem je pojednání o jednotlivých přijímaných změnách, především v zákonech o Ústavním soudu, Nejvyšším soudu a Národní soudcovské radě. Dále se práce zaměřuje na kritiku ze strany EU, resp. SDEU, která má za cíl narovnat vadný právní stav.ObhájenoThe thesis presents the issue of the constitutional crisis in Poland, which emerged in 2015 and whose subject, in addition to judicial reforms, is mainly the systemic violation of the rule of law. The content is a discussion of individual changes adopted, especially in the laws on the Constitutional Court, the Supreme Court and the National Judicial Council. Furthermore, the work focuses on the criticism from the EU or the CJEU, which aims to straighten out the defective legal situation

Spatial variability of hydrolytic and oxidative potential enzyme activities in different subsoil compartments.

© 2015 Springer-Verlag Berlin Heidelberg The spatial heterogeneity of nutrient turnover in subsoils has been rarely studied in the past, although drilosphere and rhizosphere are found to be important microbial hotspots in this oligotrophic environment. In this study, we measured different potential enzyme activities in different soil compartments of subsoil and topsoil. It could be shown that the activities of hydrolases, which cleave readily available organic substrates, are significantly higher in samples from the drilosphere and rhizosphere both in topsoil and subsoil. In bulk soil, hydrolase activities decrease with depth. In contrast, oxidative enzymes, which are involved in the decay of recalcitrant organic material, are released from the microbial community especially in the bulk fraction of subsoil. This emphasizes the importance of subsoil for nutrient acquisition and gives evidence for a distinct spatial separation of microbes with diverging lifestyles

Community structure of prokaryotes and their functional potential in subsoils is more affected by spatial heterogeneity than by temporal variations.

Spatial and temporal dynamics of microbial community structure and function in subsoils have been rarely studied in the past. In this paper we present data on how bacterial communities as well as selected functional groups of microbes change in the rhizosphere, the drilosphere, and in bulk soil over time in topsoil as well as in subsoil. We show that the overall richness of bacteria and abundance of nitrifiers and denitrifiers decreases in bulk soil with soil depth. However, these effects were not or to a much lower degree observed in the rhizosphere and the drilosphere. Temporal fluctuations contributed by far less than spatial factors to the dynamics of bacterial communities and abundance of nitrifiers and denitrifiers in all compartments independent from the soil depth

Characterization of the metallo-cofactors of the tetrachloroethene reductive dehalogenase purified from Sulfurospirillum multivorans

Sulfurospirillum multivorans is an epsilonproteobacterium able to grow anaerobically with hydrogen as electron donor and tetrachloroethene (PCE) as terminal electron acceptor (organohalide respiration). The dechlorination is mediated by the PCE reductive dehalogenase (PceA), which is a corrinoid-containing iron-sulfur protein [1]. This enzyme is located at the periplasmic face of the cytoplasmic membrane [2] and represents the terminal oxidoreductase of a so far uncharacterized membrane-associated respiratory chain. The corrinoid cofactor of PceA was shown to be Norpseudo-B12. However, until now, only little is known about the role of the iron-sulfur clusters in the electron transfer within the enzyme. In this study a mutant strain of S. multivorans producing an affinity-tagged PceA was characterized with regard to growth and the ability to dechlorinate PCE as terminal electron acceptor. A simplified protocol for PceA purification was established and optimized for a fast and efficient isolation of pure and homogenous recombinant PceA in high amounts. The iron content and the number of corrinoids per molecule PceA were quantified. Using electron paramagnetic resonance spectroscopy (EPR) and concomitant redox titration, the type of the Fe-S clusters and their midpoint redox potentials were determined. In addition, the midpoint redox potentials of the corrinoid cofactor were measured and compared to already published data [3]. From the experiments presented here a tentative scheme of the electron transport pathway in the PCE respiratory chain of S. multivorans was derived that combines recent biochemical and spectroscopical results

Abundance of ammonia oxidizing microbes and denitrifiers in different soil horizons of an agricultural soil in relation to the cultivated crops.

The role of subsoils and their microbial communities for the nutrient supply for plants is to a large extent unknown, especially in comparison to well investigated topsoil layers. Therefore, in this study, the influence of three different plant species with different rooting systems and different N uptake strategies on ammonium and nitrate levels and microbial communities involved in ammonia oxidation and denitrification was investigated in different soil horizons. Overall, our results show a higher genetic potential for both processes in topsoils than in subsoils independent of the present plant. Although we found accumulation of N in top and subsoils in plots with legumes, we could not observe an impact of the higher nitrate content on the genetic potential of denitrification and ammonia oxidation. However, differences in the ratios of ammonia oxidizing archaea to bacteria and also between denitrifying bacteria harboring genes for copper- (nirK) or cytochrome- (nirS) dependent nitrite reductase in top and subsoil samples reveal different ecophysiologies of microbes involved in N turnover in top and subsoil habitats

Prokaryotes in subsoil - evidence for a strong spatial separation of different phyla by analysing co-occurrence networks.

Microbial communities in soil provide a wide range of ecosystem services. On the small scale, nutrient rich hotspots in soil developed from the activities of animals or plants are important drivers for the composition of microbial communities and their functional patterns. However, in subsoil, the spatial heterogeneity of microbes with differing lifestyles has been rarely considered so far. In this study, the phylogenetic composition of the bacterial and archaeal microbiome based on 16S rRNA gene pyrosequencing was investigated in the soil compartments bulk soil, drilosphere, and rhizosphere in top- and in the subsoil of an agricultural field. With co-occurrence network analysis, the spatial separation of typically oligotrophic and copiotrophic microbes was assessed. Four bacterial clusters were identified and attributed to bulk topsoil, bulk subsoil, drilosphere, and rhizosphere. The bacterial phyla Proteobacteria and Bacteroidetes, representing mostly copiotrophic bacteria, were affiliated mainly to the rhizosphere and drilosphere—both in topsoil and subsoil. Acidobacteria, Actinobacteria, Gemmatimonadetes, Planctomycetes, and Verrucomicrobia, bacterial phyla which harbor many oligotrophic bacteria, were the most abundant groups in bulk subsoil. The bacterial core microbiome in this soil was estimated to cover 7.6% of the bacterial sequencing reads including both oligotrophic and copiotrophic bacteria. In contrast the archaeal core microbiome includes 56% of the overall archaeal diversity. Thus, the spatial variability of nutrient quality and quantity strongly shapes the bacterial community composition and their interaction in subsoil, whereas archaea build a stable backbone of the soil prokaryotes due to their low variability in the different soil compartments