Einfluss fermentierter organischer Dünger auf Spurengasemissionen im Ökologischen Pflanzenbau

Agriculture belongs to the major sources of the trace gases nitrous oxide (N2O) and methane (CH4). However, little is known about the contribution of the increasing area of organically managed arable soils in organic farming systems to the greenhouse gas emissions. The objective of our study was the quantification of the in-situ N2O- and CH4- emissions in common organic crop cultivation without livestock. In comparison to this control variant, we focused on the manuring effect of fermented herbal organic matter on the emissions (biogas variant). The straw of the crops and the growth of the intercrops were harvested, fermented in a biogas reactor and applied as fertilizer on the field when the nutrient demand of the crops occurred. The results obtained in 2003/2004 in winter wheat generally revealed a low level of N2O emissions and indicated reduced losses (458 g N ha-1 yr-1) of the soil in the biogas variant compared to the control variant (770 g N ha-1 yr-1). Measurements of the CH4 fluxes showed a slightly decreased CH4 uptake rate in the biogas variant (484 g C ha-1 yr-1) in comparison to the control variant (591 g C ha-1 yr-1)

Domestication Impacts the Wheat-Associated Microbiota and the Rhizosphere Colonization by Seed- and Soil-Originated Microbiomes, Across Different Fields

The seed-transmitted microorganisms and the microbiome of the soil in which the plant grows are major drivers of the rhizosphere microbiome, a crucial component of the plant holobiont. The seed-borne microbiome can be even coevolved with the host plant as a result of adaptation and vertical transmission over generations. The reduced genome diversity and crossing events during domestication might have influenced plant traits that are important for root colonization by seed-borne microbes and also rhizosphere recruitment of microbes from the bulk soil. However, the impact of the breeding on seed-transmitted microbiome composition and the plant ability of microbiome selection from the soil remain unknown. Here, we analyzed both endorhiza and rhizosphere microbiome of two couples of genetically related wild and cultivated wheat species (Aegilops tauschii/Triticum aestivum and T. dicoccoides/T. durum) grown in three locations, using 16S rRNA gene and ITS2 metabarcoding, to assess the relative contribution of seed-borne and soil-derived microbes to the assemblage of the rhizosphere microbiome. We found that more bacterial and fungal ASVs are transmitted from seed to the endosphere of all species compared with the rhizosphere, and these transmitted ASVs were species-specific regardless of location. Only in one location, more microbial seed transmission occurred also in the rhizosphere of A. tauschii compared with other species. Concerning soil-derived microbiome, the most distinct microbial genera occurred in the rhizosphere of A. tauschii compared with other species in all locations. The rhizosphere of genetically connected wheat species was enriched with similar taxa, differently between locations. Our results demonstrate that host plant criteria for soil bank’s and seed-originated microbiome recruitment depend on both plants’ genotype and availability of microorganisms in a particular environment. This study also provides indications of coevolution between the host plant and its associated microbiome resulting from the vertical transmission of seed-originated taxa

Elevated Atmospheric {CO}2 Modifies Mostly the Metabolic Active Rhizosphere Soil Microbiome in the Giessen {FACE} Experiment

Elevated levels of atmospheric CO2 lead to the increase of plant photosynthetic rates, carbon inputs into soil and root exudation. In this work, the effects of rising atmospheric CO2 levels on the metabolic active soil microbiome have been investigated at the Giessen free-air CO2 enrichment (Gi-FACE) experiment on a permanent grassland site near Giessen, Germany. The aim was to assess the effects of increased C supply into the soil, due to elevated CO2, on the active soil microbiome composition. RNA extraction and 16S rRNA (cDNA) metabarcoding sequencing were performed from bulk and rhizosphere soils, and the obtained data were processed for a compositional data analysis calculating diversity indices and differential abundance analyses. The structure of the metabolic active microbiome in the rhizospheric soil showed a clear separation between elevated and ambient CO2 (p = 0.002); increased atmospheric CO2 concentration exerted a significant influence on the microbiomes differentiation (p = 0.01). In contrast, elevated CO2 had no major influence on the structure of the bulk soil microbiome (p = 0.097). Differential abundance results demonstrated that 42 bacterial genera were stimulated under elevated CO2. The RNA-based metabarcoding approach used in this research showed that the ongoing atmospheric CO2 increase of climate change will significantly shift the microbiome structure in the rhizosphere

The transcriptionally active bacterial communities of grapevine rhizosphere in dependence on rootstock and scion variety

The rhizosphere is where crucial processes for the productivity of viticultural systems occur. The composition of the bacterial communities associated with the rhizosphere of grapevines is known to depend on plant genotype. However, the genotype of grafted grapevines differs between scion and rootstock; the role of each genotype is unclear. To untangle the effect of scion and rootstock, the rRNA (V4–V5 region of 16S rRNA) extracted from the rhizosphere of the grape varieties Riesling and Mueller-Thurgau ungrafted vs grafted on different rootstocks was sequenced. The bioinformatic analysis with tools designed to be robust for compositional data showed that the investigated rootstocks or scions or combinations, respectively, recruited bacterial communities with distinguishable traits. Statistical differences were revealed between ungrafted Riesling vs Mueller-Thurgau, between grafted Riesling vs ungrafted Riesling, and between ungrafted Mueller-Thurgau vs grafted Mueller-Thurgau. Thus, confirming the role of scion and rootstock genotype as a driver of the structure and composition of bacterial communities in the rhizosphere of grapevines

Bacterial Species Associated with Highly Allergenic Plant Pollen Yield a High Level of Endotoxins and Induce Chemokine and Cytokine Release from Human A549 Cells

none10siSensitization to pollen allergens has been increasing in Europe every year. Most studies in this field are related to climate change, phenology, allergens associated with different pollens, and allergic disorders. As a plant microhabitat, pollen is colonized by diverse microorganisms, including endotoxin-producing bacteria which may contribute to pollen allergy (pollinosis). Therefore, bacteria isolated from high allergenic and low allergenic plant pollen, as well as the pollen itself with all microbial inhabitants, were used to assess the effect of the pollen by measuring the endotoxins lipopolysaccharides (LPS) and lipoteichoic acid (LTA) concentrations and their effect on chemokine and cytokine release from transwell cultured epithelial A549 cells as a model of epithelial lung barrier. High allergenic pollen showed a significantly higher level of bacterial endotoxins; interestingly, the endotoxin level found in the bacterial isolates from high allergenic pollen was significantly higher compared to that of bacteria from low allergenic pollen. Moreover, bacterial LPS concentrations across different pollen species positively correlated with the LPS concentration across their corresponding bacterial isolates. Selected bacterial isolates from hazel pollen (HA5, HA13, and HA7) co-cultured with A549 cells induced a potent concentration-dependent release of the chemokine interleukin-8 and monocyte chemotactic protein-1 as well as the cytokine TNF-alpha and interleukin-2 to both apical and basal compartments of the transwell model. This study clearly shows the role of bacteria and bacterial endotoxins in the pollen allergy as well as seasonal allergic rhinitis.Ambika Manirajan, Binoy; Hinrichs, Ann-Kathrin; Ratering, Stefan; Rusch, Volker; Schwiertz, Andreas; Geissler-Plaum, Rita; Eichner, Gerrit; Cardinale, Massimiliano; Kuntz, Sabine; Schnell, SylviaAmbika Manirajan, Binoy; Hinrichs, Ann-Kathrin; Ratering, Stefan; Rusch, Volker; Schwiertz, Andreas; Geissler-Plaum, Rita; Eichner, Gerrit; Cardinale, Massimiliano; Kuntz, Sabine; Schnell, Sylvi

Einfluss von Cd-, Cu- und Zn-Kontaminationen auf die mikrobielle Population und Respiration in bewässerten Kastanozems in SE-Georgien

Das Untersuchungsgebiet befindet sich etwa 80 km südlich der Hauptstadt Tiflis im Mashavera-Tal in SE-Georgien. Aufgrund kontinentaler Klimabedingungen (504 mm) werden die intensiv landwirtschaftlich genutzten Böden mit Wasser aus dem Mashavera-Fluss bewässert. Der Fluss ist stark mit spurenmetallhaltigen (Cd, Cu, Zn) Schwebstoffen belastet, die aus Erosionsprozessen von Abraumhalden und Abwassereinleitungen der Flotationsanlagen einer NE-Metallmine stammen. Hierdurch werden die bewässerten Böden im Mashavera-Tal großflächig mit Cd, Cu und Zn belastet. Im Rahmen der Untersuchungen wurden die Auswirkungen der Spurenmetallbelastung auf die Lebensraumfunktion der Böden geprüft. Die im Mashavera-Tal anthropogen verursachte Cd-, Cu- und Zn-Kontamination der landwirtschaftlich genutzten Böden wirkt sich negativ auf die untersuchten mikrobiellen Parameter aus. Auf stark belasteten Flächen ist ein deutlicher Rückgang der mikrobiellen Respiration zu verzeichen. Zudem zeigt sich eine geringere Diversität in der bakteriellen Populationsstruktur in stark belasteten Bodenproben

Critical raw materials – Advanced recycling technologies and processes: Recycling of rare earth metals out of end of life magnets by bioleaching with various bacteria as an example of an intelligent recycling strategy

The current ongoing transition in the energy and mobility sector is partially based on elements which can be classified as critical, like rare earths and cobalt. For these elements recycling can be one option to lower the demand on primary raw materials. Nevertheless the complexity of devices is high making recycling for technology metals complicated. Therefore the generation of concentrated fractions is an important step in the process chain of treating secondary raw materials. In addition to the established classification and sorting processes based on physical principles there is an increasing demand for intelligent solutions to meet the growing complexity and heterogeneity of material flows. Conventional recycling strategies based on pyrometallurgical or hydrometallurgical processes can quickly become costly due to a high energy requirement and usage of chemicals. Bioleaching offers a green recycling strategy, where leaching of waste material is performed by microorganisms. In this study the recycling potential of end-of life magnets was investigated by means of bioleaching with various bacteria. The experiments were done in shaking batches, whereby in parallel the chemical leaching represented by abiotic controls was followed. As sample material magnets with different alloy composition and particle sizes were examined. The experiments were quantified using ICP-OES, µ-XRF, XRD and SEM with EDX. All samples could be successfully bioleached. The highest leaching efficiencies were determined in approaches with Acidithiobacillus and Leptospirillum ferrooxidans. Leaching efficiencies up to 100% (Dy, Pr) were achieved. According to leaching efficiencies of the abiotic controls were in the same range as in biotic batches a chemical leaching by acids was detected as dominant. However, batches with an iron addition showed higher leaching due to the catalytic effect of Fe3+ ions. On the other hand bioleaching was exposed as more efficient due to lower costs, a less use of chemicals and lower pollution due to emissions and contaminated residues. An up-scaling of the investigated process was done in a bioreactor, wherein no loss in efficiency was recorded. The obtained solution was further purified by processes to extract the rare earth elements. The precipitation with oxalic acid and a two-step extraction was identified as the most efficient methods. Extraction rates of the REE up to 100% with a purity of 98% were achieved

Use of Laser Microdissection for Phylogenetic Characterization of Polyphosphate-Accumulating Bacteria▿

Our novel approach for taxonomic identification of uncultured bacteria harboring specific physiological features in complex environmental samples combines cell collection by laser microdissection and subsequent DNA analysis. The newly developed approach was successfully tested for collection and phylogenetic characterization of polyphosphate-accumulating bacteria in activated sludge and lake sediment