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Group Members and Projects

Dr. Thomas Wichard (Principal Investigator)

Our group investigates symbiotic interactions between eukaryotes and prokaryotes based on information chemicals. By combining bioassays and chemical analytical methods, we gain insights into the complex network of info chemicals/signal molecules and their eco-physiological significance.

The focus of our research:

(1) The chemosphere of the marine green alga Ulva mutabilis with its symbiotic bacteria during biocenosis formation.

(2) Regulation of gametogenesis and release of gametes by sporulation and swarm inhibitors of Ulva mutabilis.

(3) The bacteria induced morphogenesis of Ulva mutabilis.

(4) The mobilisation of trace elements by metallophores.

Our lab at ResearchGate

Email: thomas.wichard at uni-jena.de



Dr. Michiel Kwantes (PostDoc)

Michiel foto IAAA 2016

The main objectives of the project are to elucidate the signal-mediated cross-kingdom interactions between the marine green macroalgae Ulva mutabilis and its associated bacteria applying forward genetics including insertional mutagenesis of Ulva.

Publications

Bösger, J., Kwantes, M., Wichard, T* (2018) Polyethylene glycol (PEG)-mediated transformation in the green macroalgae Ulva mutabilis (Chlorophyta): a forward genetic approach. In Protocols for Macroalgae Research, eds. B. Charrier, T. Wichard, C.R.K. Reddy, Chapter 31. Boca Raton: CRC Press, Francis & Taylor Group.



Gianmaria Califano (PhD Student)

Master degree in Marine Biology and Conservation, Universities of Algarve and Oviedo, Portugal


gianmaria_pic_profile

The project aims to get new insights into the molecular mechanisms of symbiosis or antibiosis between U. mutabilis and its associated bacteria, I am aiming to develop a symbiosis model as a basis to engineer microbial communities for macroalgal aquacultures.

Please see the video about my project.

Califano, G., Wichard, T.* (2018) Preparation of axenic cultures in Ulva (Chlorophyta). In Protocols for Macroalgae Research, eds. B. Charrier, T. Wichard, C.R.K. Reddy, Chapter 9. Boca Raton: CRC Press, Francis & Taylor Group. In Press

Kuhlisch, C., Califano, G., Wichard, T., Pohnert, G.* (2018) Metabolomics of intra- and extracellular metabolites from micro- and macroalgae using GC-MS and LC-MS. In Protocols for Macroalgae Research, eds. B. Charrier, T. Wichard, C.R.K. Reddy, Chapter 18. Boca Raton: CRC Press, Francis & Taylor Group.

Email: Gianmaria.Califano at uni-jena.de



Michael Deicke (PhD Student)

1. Staatsexamen in Chemie und Geschichte (LA Gym.), Friedrich-Schiller-Universität Jena
Postgraduales Studium der Biologie

Michael Deicke

Projektbeschreibung (Promotionsthema):
Identifizierung und Charakterisierung von Metallophoren des stickstofffixierenden Bodenbakteriums Frankia alni. Insbesondere wird die Bedeutung der Metallophore für die Symbiose zwischen Frankia alni und der Erle Alnus glutinosa erforscht. Dieses Projekt wird durch die Hans-Böckler-Stiftung gefördert.

Projektbeschreibung (Staatsexamensarbeit, 2011):
Molybdänaufnahme von Stickstofffixierern: Analyse von Metallkomplexen mittels UPLC/MS

Publications:

Baumeister, T. U. H., Ueberschaar, N., Schmidt-Heck, W., Mohr J. F., Deicke M., Wichard, T.*, Guthke R., Pohnert, G.* (2018) DeltaMS: A tool to track isotopologues in GC- and LC-MS data. Metabolomics 14:41.

Kuhlisch, C.,  Deicke, M., Ueberschaar,  N., Wichard,  T., Pohnert, G. (2016) A fast and direct liquid chromatography-mass spectrometry method to detect and quantify polyunsaturated aldehydes and polar oxylipins in diatoms. Limnology and Oceanography Methods. doi:10.1002/lom3.10143

Noumsi, J., C., Pourhassan, N., Darnajoux, R., Deicke, M., Wichard, T., Burrus, V., Bellenger, J-B. (2016) Effect of organic matter on nitrogenase metal cofactors homeostasis in Azotobacter vinelandii under diazotrophic conditions. Environmental Microbiology Reports, 8: 76-84. doi: 10.1111/1758-2229.12353

Deicke, M., Mohr, J. F., Bellenger, J. P., Wichard, T. (2014) Metallophore mapping in complex matrices by metal isotope coded profiling of organic ligands. Analyst, 23, 6096 - 6099

Deicke, M., Bellenger, J. P., Wichard, T. (2013) Direct quantification of bacterial molybdenum and iron metallophores with ultra-high-performance liquid chromatography coupled to time-of-flight mass spectrometry. Journal of Chromatography A, 1258, 50-60

Email: Michael.Deicke at uni-jena.de



Ralf Keßler (PhD Student)

Diplom in Umweltchemie, Friedrich-Schiller-Universität Jena

 Bild Kessler

Projektbeschreibung (Promotionsthema): Aquakulturen mariner Makroalge
Das Projekt zielt darauf ab das Wachstum, die Fortpflanzung und die Regulation des Lebenszyklus von Ulva am Beispiel des Modellorganismus Ulva mutabilis und seiner symbiontischen Bakterien unter besonderer Berücksichtigung der chemischen Ökologie zu verstehen: Die Alge befindet sich entweder im Lebensabschnitt des Gametophyten oder des Sporophyten. Während der Gametogenese kann sich eine grüne Blattzelle zu einem Gametangium differenzieren (auch "Sporulation" genannt), wenn regulierende Inhibitoren, die Sporulationsinhibitoren SI-1 und SI-2, altersbedingt einen Schwellenwert unterschritten haben. Die Inhibitoren werden isoliert und ihre Strukturen aufgeklärt. Anschließend sollen die Sporulationsinhibitorenn zur Regulation algalen Wachstums in Aquakulturen eingesetzt werden. Dieses Projekt wird durch die Deutsche Bundesstiftung Umwelt (DBU) gefördert.

Projektbeschreibung der Diplomarbeit (2012)
Identifizierung und Charakterisierung von Sporulations- und Swärminhibitoren zur Regulation der Gametogenese in der marinen Makroalge Ulva sp. Zu Beginn der Gametangiendifferenzierung von Ulva lactuca und Ulva mutabilis wird ein "Schwärminhibitor" (SWI) in die Umgebung ausgeschieden, der ein vorzeitiges Ausschwärmen der reifen Gameten aus den Gametangien verhindert. Der synchrone Schwärmvorgang wird erst durch Ausverdünnen des Schwärminhibitors und durch Rotlicht induziert und erfolgt innerhalb weniger Minuten. Der Schwärminhibitor soll bis zur Reinsubstanz gereinigt und seine Struktur aufgeklärt werden.
Die Diplomarbeit wird durch die ASSEMBLE EU-Infrastrukturmaßnahmen gefördert: An der marinen biologischen Station Ramalhete (Faro, Portugal) werden Aquakulturen von Ulva sp. angelegt, um eine ausreichende Biomasse zur Identifizierung von Sporulationsinhibitoren zu erzeugen. (Wichard & Oertel 2010, Journal of Phycology)

Publications:

Kessler, R.W.1, Weiss, A.1, Kuegler, S., Hermes, C. Wichard, T.* (2018) Macroalgal-bacterial interactions: Role of dimethylsulfoniopropionate in microbial gardening by Ulva (Chlorophyta). Molecular Ecology 27: 1808-1819.

Kessler, R.W., Alsufyani, T., Wichard, T.* (2018) Purification of sporulation and swarming inhibitors from Ulva: application in algal life cycle controlling. In Protocols for Macroalgae Research, eds. B. Charrier, T. Wichard, C.R.K. Reddy, Chapter 8. Boca Raton: CRC Press, Francis & Taylor Group.

Kessler, R.W., Crecelius, A.C.*, Schubert, U.S., Wichard, T.* (2017) In situ monitoring of molecular changes during cell differentiation processes in marine macroalgae through mass spectrometric imaging. Analytical Bioanalytical Chemistry 409: 4893-4903. doi:10.1007/s00216-017-0430-7 

Vesty, E.F., Kessler, R. W., Wichard, T.*, Coates, J.C.* (2015) Regulation of gametogenesis and zoosporogenesis in Ulva linza (Chlorophyta): comparison with Ulva mutabilis and potential for laboratory culture. Front. Plant Sci. 6:15. doi: 10.3389/fpls.2015.00015

Email: Ralf.Kessler at uni-jena.de



Jan Frieder Mohr (PhD Student)

Diplom in Environmental Chemistry, Friedrich-Schiller-Universität Jena

Jan Frieder Mohr

This project aims to identify novel metallophores based on recently developed LC/MS analytical techniques and to unravel their multiple functions particularly in nitrogen-fixing and microbial iron-cycling systems. To mimic natural sources of molybdenum, which is an essential cofactor of nitrogenases, we will develop libraries of synthetic chelating agents for molybdenum. The resulting complexes serve as “Mo-buffers” to control the availability of molybdenum species in aqueous cultures. To model redox shuttle systems in communities of Fe(II) oxidizers and Fe(III) reducers appropriate ligands as well as metal complexes will be developed.

Publications:

Kügler, S., Cooper, R.,E., Wegner, C.-E., Mohr, J.F., Wichard, T., Küsel, K.* (2019) Iron-organic matter complexes accelerate microbial iron cycling in an iron-rich fen. Science of Total Environment 646: 972-988.

Hermenau, R., Keishi, I., Gama, S., Hoffmann, B., Pfeifer-Leeg, M., Plass, W., Mohr, J.F., Wichard, T., Saluz H.,P., Hertweck, C.* (2018) Gramibactin is a bacterial siderophore with a diazeniumdiolate ligand system. Nature Chemical Biology. Online https://doi.org/10.1038/s41589-018-0101-9.

Baumeister, T. U. H., Ueberschaar, N., Schmidt-Heck, W., Mohr J. F., Deicke M., Wichard, T.*, Guthke R., Pohnert, G.* (2018) DeltaMS: A tool to track isotopologues in GC- and LC-MS data Metabolomics 14:41.

Deicke, M., Mohr, J. F., Bellenger, J. P., Wichard, T. (2014) Metallophore mapping in complex matrices by metal isotope coded profiling of organic ligands. Analyst, 23, 6096 - 6099.

Email: jan-frieder.mohr at uni-jena.de



Anne Weiß (PhD Student)

Diplom in Biology, Friedrich-Schiller-Universität Jena 

Anne

Ulva mutabilis is developing properly only in association with the two bacterial strains Roseobacter sp. and Cytophaga sp. or their morphogenetic compounds extracted from the bacterial supernatant. The Roseobacter species exhibits a specific chemotactic affinity to the rhizoid cells of U. mutabilis and seems to cooperate with the Cytophaga strain and the alga by chemical communication. We are interested in the cross-kingdom cross-talk and interaction from the "first contact" of axenic U. mutabilis gametes with its symbiotic bacteria till the formation of a tripartite system. This includes: (i) the localisation of epiphytic bacteria and the monitoring of biofilm formation, (ii) metabolic changes in gametes and bacteria during "first contact" and (iii) the identification of the bacterial perception system. This project is funded by the Jena School for Microbial Communication (JSMC).

Publications:

Kessler, R.W.1, Weiss, A.1, Kuegler, S., Hermes, C. Wichard, T.* (2018) Macroalgal-bacterial interactions: Role of dimethylsulfoniopropionate in microbial gardening by Ulva (Chlorophyta). Molecular Ecology 27: 1808-1819.

Weiss, A., Costa, R., Wichard, T. (2017) Morphogenesis of Ulva mutabilis (Chlorophyta) induced by Maribacter species (Bacteroidetes, Flavobacteriaceae). Botanica Marina 60(2): 197-206. doi:10.1515/bot-2016-0083

Katsaros, C., Weiss, A., Llangos, I., Theodorou, I., Wichard, T. (2017) Cell structure and microtubule organisation during gametogenesis of Ulva mutabilis Føyn (Chlorophyta) Botanica Marina 60(2):123-135. doi:10.1515/bot-2016-0073

Alsufyani, T., Weiss, A., Wichard, T. (2017) Time Course Exo-Metabolomic Profiling in the Green Marine Macroalga Ulva (Chlorophyta) for Identification of Growth Phase-Dependent Biomarkers. Mar. Drugs 15: 14. doi:10.3390/md15010014

Email: Anne.Weiss at uni-jena.de