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Wolfgang Schmidt-Heck

About Wolfgang Schmidt-Heck:
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SEEK ID: https://data.chembiosys.de/people/31

Location:  Germany

Expertise: Not specified

Tools: Not specified

ORCID: Not specified

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Project positions

A1 (Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute) ; A2 (Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute) ; A3 (Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute) ; A4 (Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute) ; B1 (Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute) ; B2 (Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute) ; B3 (Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute) ; B4 (Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute) ; B05 (Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute) ; B6 (Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute) ; C1 (Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute) ; C2 (Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute) ; C3 (Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute) ; C4 (Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute) ; C5 (Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute) ; Total ChemBioSys (Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute) ; Z01 (Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute) ; Z02 (Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute) ; Associated project 2 (Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute) ; Associated project 1 (Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute)

Related items

C2

Are Plant Defenses Chemicals Commonly Sequestered and Metabolized by their Herbivores to Function as Infochemicals in Higher Trophic Level Interactions in Nature?

Public web page: Not specified

Total ChemBioSys
No description specified

Public web page: Not specified

C1

Algicidal Bacteria in Plankton Communities: Resistance, Lysis and Heterotrophy

Public web page: Not specified

C3

Thiopeptide Signals in Actinomycete Communities

Public web page: Not specified

C4

Metallophores as Mediators for Metal Cycling: Profiling and Ecological Evaluation of Ligands Involved in the Microbial Cycling of Iron in Complex Systems

Public web page: Not specified

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Thermodynamic study on 8-hydroxyquinoline-2-carboxylic acid as a chelating agent for iron found in the gut of Noctuid larvae
C5, Z01

Abstract (Expand)

The recognition of quinolinic carboxylic acids as natural chelants and the recent observation of a high production of 8-hydroxyquinoline-2-carboxylic acid (8-HQA) in the gut of several Noctuid larvae … (e.g. Spodoptera littoralis) has inspired the study of the chelation properties of 8-HQA towards Fe2+ and Fe3+. Here, we report a detailed characterization of the thermodynamic solution behaviour of Fe2+/8-HQA and Fe3+/8-HQA systems as a function of the pH value. The acid–base properties of 8-HQA and its binding ability towards Fe2+ and Fe3+ have been investigated over a wide range of pH values (2.0 ≤ pH ≤ 11.0) by ISE-H+ (glass electrode) potentiometric titrations in KCl(aq) at I = 0.2 mol dm−3 and at T = 298.15 K. For both oxidation states, various FeLqHr species are formed, with q = 1, 2 (and 3), and −2 ≤ r ≤ 1. The presence of the main FeLqHr species was confirmed by HESI-HRMS. ESR measurements have also been performed to get some extra information on the Fe3+ coordination, indicating a distorted octahedral symmetry around the metal center. Quantum mechanical calculations have been carried out in order to characterize the structural features of selected metal complexes. The complexing ability of 8-HQA is generally much higher for Fe3+ than Fe2+. Nevertheless, the sequestering ability of 8-HQA towards these two oxidation states of this metal ion, obtained by the calculation of several pL0.5 values, resulted in it being highly dependent on the pH value: (i) at relatively low pH values, it is higher for Fe3+ (pL0.5 = 6.3 at pH = 3.0) than for Fe2+ (pL0.5 = 3.1 at pH = 3.0); (ii) it is almost the same at pH = 8.1 (Fe3+: pL0.5 = 8.3; Fe2+: pL0.5 = 8.1); (iii) it is higher for Fe2+ at high pH values (pL0.5 = 8.9 for Fe2+ and pL0.5 = 6.2 for Fe3+ at pH = 10.0). The determination of the stability constants of the Fe2+/8-HQA and Fe3+/8-HQA complexes was also complemented by data obtained by the ligand-competition approach, using EDTA as a competing ligand over a wide range of cation and ligand concentrations and ratios. This also allowed a more thorough investigation of both the Fe2+/EDTA and Fe3+/EDTA systems, providing an accurate stability constant dataset for the Fep(EDTA)qHr species under the above-mentioned experimental conditions, which are commonly used in biological studies.

Authors: Sofia Gama, Mariachiara Frontauria, Nico Ueberschaar, Giuseppe Brancato, Demetrio Milea, Silvio Sammartano, Winfried Plass

Date Published: 9th Apr 2018

Publication Type: Not specified

DeltaMS: a tool to track isotopologues in GC- and LC-MS data
C5, Z01, INF

Abstract (Expand)

Introduction: Stable isotopic labeling experiments are powerful tools to study metabolic pathways, to follow tracers and fluxes in biotic and abiotic transformations and to elucidate molecules involved …d in metal complexing. Objective: To introduce a software tool for the identification of isotopologues from mass spectrometry data. Methods: DeltaMS relies on XCMS peak detection and X13CMS isotopologue grouping and then analyses data for specific isotope ratios and the relative error of these ratios. It provides pipelines for recognition of isotope patterns in three experiment types commonly used in isotopic labeling studies: (1) Search for isotope signatures with a specific mass shift and intensity ratio in one sample set. (2) Analyze two sample sets for a specific mass shift and, optionally, the isotope ratio, whereby one sample set is isotope-labeled, and one is not. (3) Analyze isotope-guided perturbation experiments with a setup described in X13CMS. Results: To illustrate the versatility of DeltaMS, we analyze data sets from case-studies that commonly pose challenges in evaluation of natural isotopes or isotopic signatures in labeling experiment. In these examples, the untargeted detection of sulfur, bromine and artificial metal isotopic patterns is enabled by the automated search for specific isotopes or isotope signatures. Conclusion: DeltaMS provides a platform for the identification of (pre-defined) isotopologues in MS data from single samples or comparative metabolomics data sets.

Authors: Tim U. H. Baumeister, Nico Ueberschaar, Wolfgang Schmidt-Heck, J. Frieder Mohr, Michael Deicke, Thomas Wichard, Reinhard Guthke, Georg Pohnert

Date Published: 27th Feb 2018

Publication Type: Not specified

Plant-mediated RNAi silences midgut-expressed genes in congeneric lepidopteran insects in nature.
C2

Abstract (Expand)

BACKGROUND: Plant-mediated RNAi (PMRi) silencing of insect genes has enormous potential for crop protection, but whether it works robustly under field conditions, particularly with lepidopteran pests, … remains controversial. Wild tobacco Nicotiana attenuata and cultivated tobacco (N. tabacum) (Solanaceae) is attacked by two closely related specialist herbivores Manduca sexta and M. quinquemaculata (Lepidoptera, Sphingidae). When M. sexta larvae attack transgenic N. attenuata plants expressing double-stranded RNA(dsRNA) targeting M. sexta's midgut-expressed genes, the nicotine-ingestion induced cytochrome P450 monooxygenase (invert repeat (ir)CYP6B46-plants) and the lyciumoside-IV-ingestion induced beta-glucosidase1 (irBG1-plants), these larval genes which are important for the larvae's response to ingested host toxins, are strongly silenced. RESULTS: Here we show that the PMRi procedure also silences the homologous genes in native M. quinquemaculata larvae feeding on irCYP6B46 and irBG1-transgenic N. attenuata plants in nature. The PMRi lines shared 98 and 96% sequence similarity with M. quinquemaculata homologous coding sequences, and CYP6B46 and BG1 transcripts were reduced by ca. 90 and 80%, without reducing the transcripts of the larvae's most similar, potential off-target genes. CONCLUSIONS: We conclude that the PMRi procedure can robustly and specifically silence genes in native congeneric insects that share sufficient sequence similarity and with the careful selection of targets, might protect crops from attack by congeneric-groups of insect pests.

Authors: S. Poreddy, J. Li, I. T. Baldwin

Date Published: 15th Nov 2017

Publication Type: Not specified

Calcium carbonates: induced biomineralization with controlled macromorphology
C3

Abstract (Expand)

Biomineralization of (magnesium) calcite and vaterite by bacterial isolates has been known for quite some time. However, the extracellular precipitation has hardly ever been linked to different … morphologies of the minerals that are observed. Here, isolates from limestone-associated groundwater, rock and soil were shown to form calcite, magnesium calcite or vaterite. More than 92 % of isolates were indeed able to form carbonates, while abiotic controls failed to form minerals. The crystal morphologies varied, including rhombohedra, prisms and pyramid-like macromorphologies. Different conditions like varying temperature, pH or media components, but also cocultivation to test for collaborative effects of sympatric bacteria, were used to differentiate between mechanisms of calcium carbonate formation. Single crystallites were cemented with bacterial cells; these may have served as nucleation sites by providing a basic pH at short distance from the cells. A calculation of potential calcite formation of up to 2 g L−1 of solution made it possible to link the microbial activity to geological processes.

Authors: Aileen Meier, Anne Kastner, Dennis Harries, Maria Wierzbicka-Wieczorek, Juraj Majzlan, Georg Büchel, Erika Kothe

Date Published: 6th Nov 2017

Publication Type: Not specified

In Vivo Isotopic Labeling of Symbiotic Bacteria Involved in Cellulose Degradation and Nitrogen Recycling within the Gut of the Forest Cockchafer (Melolontha hippocastani).
B3

Abstract (Expand)

The guts of insects harbor symbiotic bacterial communities. However, due to their complexity, it is challenging to relate a specific symbiotic phylotype to its corresponding function. In the present … study, we focused on the forest cockchafer (Melolontha hippocastani), a phytophagous insect with a dual life cycle, consisting of a root-feeding larval stage and a leaf-feeding adult stage. By combining in vivo stable isotope probing (SIP) with 13C cellulose and 15N urea as trophic links, with Illumina MiSeq (Illumina-SIP), we unraveled bacterial networks processing recalcitrant dietary components and recycling nitrogenous waste. The bacterial communities behind these processes change between larval and adult stages. In 13C cellulose-fed insects, the bacterial families Lachnospiraceae and Enterobacteriaceae were isotopically labeled in larvae and adults, respectively. In 15N urea-fed insects, the genera Burkholderia and Parabacteroides were isotopically labeled in larvae and adults, respectively. Additionally, the PICRUSt-predicted metagenome suggested a possible ability to degrade hemicellulose and to produce amino acids of, respectively, 13C cellulose- and 15N urea labeled bacteria. The incorporation of 15N from ingested urea back into the insect body was confirmed, in larvae and adults, by isotope ratio mass spectrometry (IRMS). Besides highlighting key bacterial symbionts of the gut of M. hippocastani, this study provides example on how Illumina-SIP with multiple trophic links can be used to target microorganisms embracing different roles within an environment.

Authors: P. Alonso-Pernas, S. Bartram, E. M. Arias-Cordero, A. L. Novoselov, L. Halty-deLeon, Y. Shao, W. Boland

Date Published: 28th Oct 2017

Publication Type: Not specified

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SFB CHEMBIOSYS KICK-OFF MEETING
No description specified

Start Date: 20th Apr 2015

End Date: 20th Apr 2015

Event Website: Not specified

Country:  Germany

City: Jena

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