Thomas Wichard
Postdoctoral
Research Associate
Department
of Geosciences
M41 Guyot Hall
Princeton University
Princeton, NJ 08544
Thomas Wichard
My research focuses on the bioavailability of trace metals and the nitrogen cycle in soils. I am interested in the chemical form and bioavailability of trace metals like molybdenum and vanadium, because these elements are found at the active center of the nitrogenase that fixes dinitrogen. Specifically, I look at the production of bis- and tris-catecholates, which are produced by the soil bacterium Azotobacter in order to make the metal available to the organism. I will utilize e.g. X-ray spectroscopy to study trace metal speciation in environmental samples. My goal is to understand how trace metal availability and the regulation of nitrogenase-activity influence nitrogen fixation.
Curriculum vitae
Thomas Wichard
Princeton Environmental Institute
Princeton University
Guyot Hall
Princeton, New Jersey 08544, USA
Education
1995-2001: University of Regensburg (Germany): Diploma in Biochemistry
2002-2006: Max-Planck-Institute for Chemical Ecology, Jena (Germany): Ph.D. in Biochemistry
2004-2006: Member of the International Max-Planck Research School:
The Exploration of Ecological Interactions with Molecular and Chemical Techniques.
Master thesis (Diploma)
“Biochemical and physiological characterization of a swarming inhibitor from Ulva mutabilis”
(University of Regensburg, Prof. Dr. Wolfgang Oertel)
Thesis
“Investigation of lipoxygenase mediated chemical defenses: Diatom and Physcomitrella patens derived oxylipins”
(Max-Planck-Institute for Chemical Ecology, Prof. Dr. Georg Pohnert)
Appointments
Since Oct 2006: Dreyfus Postdoctoral Fellow in Environmental Chemistry through the Princeton Environmental Institute, USA (Prof. Dr. François Morel, Dr. Anne Kraepiel). (Investigation of Mo speciation in soils and the siderophore mediated uptake of Mo/V by the asymbiotic N2-fixing soil bacterium Azotobacter vinelandii.)
Aug 2006 - Oct 2006: Postdoctoral Research Associate at the Institute of Chemical Sciences of the Ecole polytechnique fédérale de Lausanne, Switzerland (Prof. Dr. Georg Pohnert).
Jun 2002 - Mar 2006: Scientific Assistant at the Max-Planck Institute for Chemical Ecology Jena, Germany (Prof. Dr. Georg Pohnert).
(Study on the wound activated formation of oxylipins in lower plants and diatoms. Survey of diatom-derived polyunsaturated aldehydes during the phytoplankton succession in Bretagne (Roscoff, France) and their impact on the reproductive response of copepods. Two scientific stays at the Marine Biological Station in Roscoff, France. Participation in a scientific cruise on the Adriatic Sea.)
Mar 2002- Apr 2002: Scientific Assistant at the Institute of Biochemistry and Genetics of the University Regensburg, Germany (Prof. Dr. Wolfgang Oertel).
(Study on the gametogenesis and the gamete release of the green algae Ulva mutabilis. Purification and biochemical characterization of the swarming inhibitor.)
May 2001-Feb 2002: Technical Assistant at the Institute of Medical Genetics (Hospital, community service) at the Ludwig-Maximilians-University of Munich, Germany (Prof. Dr. Alois Meindl).
Scientific stays and cruises
Spring 2003 & 2004: Scientific stays at the Marine Biological Station of Roscoff under the
supervision of Dr. Serge A. Poulet
March 2005: Participant on the cruise in the North Adriatic Sea (RV Urania, INTERREG monitoring program) in the team of Dr. Adriana Ianora.
Memberships
German Society for Biochemistry and Molecular Biology
British Phycological Society
American Society of Limnology and Oceanography
American Chemical Society
Publications
22. Wichard T. , Bellenger, J-B., Kraepiel A.M.L. 2008. Role of catechol siderophores for tungstate detoxification in the nitrogen fixing bacterium Azotobacter vinelandii. Environmental Science & Technology 42: 2408-2413.
21. Bellenger J.P., Wichard T., Kustka A.B., Kraepiel A.M.L. 2008. Nitrogen fixing soil bacterium uses catechol siderophores for molybdenum and vanadium acquisition. Nature Geoscience 1: 243-246.
20. Bellenger J.P., Wichard T., Kraepiel A.M.L. 2008. Vanadium requirements and uptake kinetics of the nitrogen fixing bacteria Azotobacter vinelandii. Applied and Environmental Microbiology 74: 1478-1484.
19. Wichard T. , Poulet, S.A., Boulesteix A-L., Ledoux J.B., Lebreton B., Marchetti J., Pohnert G. 2008. Influence of diatoms on copepod reproduction. II. Uncorrelated effects of diatom-derived alpha, beta, gamma, delta-unsaturated aldehydes and polyunsaturated fatty acids on Calanus helgolandicus in the field. Progress in Oceanography 77: 30-44.
18. Koski M., Wichard T., Jónasdóttir S. H. 2008. ‘Good’ and ‘bad’ diatoms: development, growth and juvenile mortality of Temora longicornis on diatom diets. Marine Biology 154: 719-734.
17. Poulet S.A., Escribano R., Hidalgo P., Cueff A., Wichard T., Aguilera V., Vargas C.A., Pohnert G. 2007. Collapse of Calanus chilensis reproduction in a marine environment with high diatom concentration. Journal of Experimental Marine Biology and Ecology 352: 187-199.
16. Wichard T. , Gerecht A., Boersma M., Poulet S. A., Wiltshire K., Pohnert G. 2007. Lipid and fatty acid composition of diatoms revisited: Rapid wound activated change of food quality parameters influences herbivorous copepod reproductive success. ChemBioChem 8: 1146-1553.
15. Ribalet F. , Wichard T., Pohnert G., Ianora A., Miralto M., Casotti R. Age and nutrient limitation enhance polyunsaturated aldehyde production in marine diatoms. Phytochemistry 68: 2059-2067.
14. Poulet S.A., Cueff A., Wichard T., Marchetti J., Dancie C., Pohnert G. 2007. Influence of diatoms on copepod reproduction. III. Consequences of abnormal oocyte maturation on reproductive factors in Calanus helgolandicus. Marine Biology 152: 415-428.
13. Wichard T., and G. Pohnert. 2006. Formation of halogenated medium chain hydrocarbons by a lipoxygenase/hydroperoxide halolyase-mediated transformation in planktonic microalgae. Journal of the American Chemical Society 128: 7114-7115.
12. Poulet S. A., Wichard T., Ledoux J.B., Lebreton B., Marchetti J., Dancie C., Bonnet D., Cueff A., Morin P., Pohnert G. 2006. Influence of diatoms on copepod reproduction. I. Field and laboratory observations related to Calanus helgolandicus egg production. Marine Ecology-Progress Series 308: 129-142.
11. Stumpe M., Bode J., Göbel C., Wichard T., Schaaf A., Frank W., Frank M., Reski R., Pohnert ., Feussner I. 2006. Biosynthesis of C9-aldehydes in the moss Physcomitrella patens. Biochimica et Biophysica Acta 1761, 301-12.
10. Wichard T., Poulet S.A., Halsband-Lenk C., Albaina A., Harris R., Liu D.Y., Pohnert G. 2005. Survey of the chemical defence potential of diatoms: Screening of fifty one species for alpha, beta, gamma, delta-unsaturated aldehydes. Journal of Chemical Ecology 31: 949-958.
9. Wichard T., Poulet S.A., Pohnert G. 2005 Determination and quantification of alpha, beta, gamma, delta-unsaturated aldehydes as pentafluorobenzyl-oxime derivates in diatom cultures and natural phytoplankton populations: application in marine field studies. Journal of Chromatography B 814: 155-161
8. Wichard T., Göbel C., Feussner I, Pohnert G. 2005. Unprecedented lipoxygenase/ hydroperoxide lyase pathways in the moss Physcomitrella patens. Angewandte Chemie International Edition 44: 158-161.
7. Senger T., Wichard T., Kunze S., Göbel C., Lerchl J., Pohnert G., Feussner I. 2005. A multifunctional lipoxygenase with fatty acid hydroperoxide cleaving activity from the moss Physcomitrella patens. Journal of Biological Chemistry 280: 7588-7596.
6. Carotenuto Y., Wichard T., Pohnert, G., Lampert W. 2005. Life-history responses of Daphnia pulicaria to diets containing freshwater diatoms: Effects of nutritional quality versus polyunsaturated aldehydes. Limnology and Oceanography 50: 449-454.
5. Horner R. A., Postel J.R., Halsband-Lenk C., Pierson J.J., Pohnert,G., Wichard T. 2005. Winter-spring phytoplankton blooms in Dabob Bay, Washington. Progress in Oceanography 67: 286-313.
4. Paffenhöfer et al. 2005. Colloquium on diatom-copepod interactions. Marine Ecology-Progress Series 286: 293-305.
3. Pohnert G., Adolph S., Wichard T. 2004. Short synthesis of labeled and unlabeled 6Z,9Z,12Z,15-hexadecatetraenoic acid as metabolic probes for biosynthetic studies on diatoms. Chemistry and Physics of Lipids 131, 159-166.
2. Ianora A., Miralto A., Poulet S.A., Carotenuto Y., Buttino I., Romano G., Casotti R., Pohnert G., Wichard T., Colucci-D'Amato L., Terrazzano G., Smetacek V. 2004. Aldehyde suppression of copepod recruitment in blooms of a ubiquitous planktonic diatom. Nature 429: 403-407.
1. Adolph S., Bach S., Blondel M., Cueff A., Moreau M., Pohnert G., Poulet S.A., Wichard T., Zuccaro A. 2004. Cytotoxicity of diatom-derived oxylipins in organisms belonging to different phyla. Journal of Experimental Biology 207: 2935-2946.
Conferences and Symposia
Oral presentations
8. Wichard, T. 2008. Ecological functions of diatom derived aldehydes: deleterious blooms & chemical signals. 7th International Chrysophyte Symposium, New London, CT (invited).
7. Wichard, T . 2007. Catechol production in Azotobacter vinelandii. CEBIC Symposium, Princeton, NJ.
6. Wichard, T. 2006. Der Einfluss des Phytoplanktons auf den Fortpflanzungserfolg von Calanus helgolandicus in den Küstengewässern vor Roscoff (Bretagne, Frankreich): Analysen von alpha, beta, gamma, delta-ungesättigte Aldehyden und Polyenfettsäuren im Jahreszyklus des Phytoplanktons. 11. Sektionstagung Phykologie Helgoland, Germany.
5. Wichard, T. 2006. ESF LESC Exploratory Workshop Influence of Phytoplankton on Herbivore Reproductive Success – Impact of Infochemicals and Food Quality? Roscoff, France (invited).
4. Wichard, T., C. Göbel, M. Stumpe, I. Feussner, and G. Pohnert. 2005. High variability of eicosanoid-transformation in lower plants. 2. European Symposium on Plant Lipids, Copenhagen, Denmark .
3. Wichard, T., S. A. Poulet, and G. Pohnert. 2005. Formation and impact of polyunsaturated aldehydes during the phytoplankton succession. ASLO Summer Meeting, Santiago de Compostela, Spain.
2. Wichard, T. 2004. Cloning and characterization of a lipoxygenase from Physcomitrella patens as a model system in the chemical defence of diatoms. Second German Middle East Plant Molecular Biology Meeting, Jena, Germany.
1. Wichard, T. 2003. Activated chemical defense mechanism of diatoms. 26. Fränkisch-Mitteldeutsches Naturstoffchemikertreffen, Würzburg, Germany.
Poster presentations
6. Wichard, T., Mishra B., Kraepiel A., Myneni S. 2008 Molybdenum Speciation and Complexation in Soils.Goldschmidt Conference, Vancouver, Canada .
5. Wichard, T., Bellenger J-P, Kraepiel A.M.L. 2007. Novel functions of siderophores in Azotobacter vinelandii. Goldschmidt Conference, Cologne, Germany.
4. Wichard, T., Pohnert G. 2006. Formation of Halogenated medium chain hydrocarbons by a lipoxygenase / hydroperoxide halololyase- mediated transformation in planktonic microalgae. 18. Irseer Naturstofftage, Germany.
3. Wichard, T., Poulet S.A., Pohnert G. 2006. The influence of diatoms on copepod reproduction: Field and laboratory observations. 54th Annual Meeting of the British Phycological Society, Plymouth, Untied Kingdom.
2. Wichard, T., Senger T., Göbel C., Kunze S. Pohnert G., Feussner I. 2005. Unprecedented oxylipin pathways in the moss Physcomitrella patens: Isolation and characterization of a new multifunctional lipoxygenase with lyase cleaving activity. XVII International Botanical Congress,Vienna, Austria.
1. Wichard, T., S. A. Poulet, and G. Pohnert. 2004. Determination of deleterious unsaturated aldehydes in phytoplankton. Proceedings XI intenational symposium on marine natural products. Sorrento, Italy.
Workshops
3. School on Synchroton X-ray and IR Methods Focusing on Environmental Sciences, ANKA, Karlsruhe, Germany, 21-23 January 2008
2. ESF LESC EXPLORATORY WORKSHOP Influence of Phytoplankton on Herbivore Reproductive Success – Impact of Infochemicals and Food Quality? Roscoff, France, 29 - 31 March 2006 (invited)
1. Colloquium on Diatom-Copepod Interactions, Benthos Laboratory of the Stazione Zoologica Anton Dohrn on Ischia, Italy, 3 to 6 November 2002
References
Prof. Dr. Georg Pohnert
Institute for Inorganic and Analytical Chemistry
Bioorganic Analytics
Friedrich-Schiller-Universität Jena
Lessingstr. 8
D-07743 Jena
Germany
Tel.: +49 3641 948170
Georg.Pohnert@uni-jena.de
Dr. Serge A. Poulet
Directeur de Recherche, CNRS
Centre National de la Recherche Scientifique,
Station Biologique de Roscoff,
Place Georges Teissier
BP74
F-29682 Roscoff Cedex
France
Tel.: +33 (0)29 8292335
Poulet@sb-roscoff.fr
Prof. Dr. Wilhelm Boland
Max Planck Institute for Chemical Ecology
Beutenberg Campus
Department of Bioorganic Chemistry
Hans-Knöll-Straße 8
D-07745 Jena
Germany
Tel.: +49 (0)3641 571200
Boland@ice.mpg.de
Updated 07/21/08