Organische Geochemie

Dr. Thorsten Bauersachs

wiss. Mitarbeiter

Ludewig-Meyn-Straße 10, R. 112
Telefon: +49 431 880-3694
Telefax: +49 431 880-4376


I am generally interested in the lipid biogeochemistry of prokaryotic and eukaryotic microorganisms and how they are involved in the cycling of nutrients on local to global scales with a focus on diazotrophic cyanobacteria. For this, I employ culture-dependent approaches to increase our knowledge on the lipid inventory of microbial organisms and study the effect of growth conditions on lipid distribution patterns on a cellular level. Information obtained from these culture studies is transferred to the geological record to reconstruct fossil ecosystems and their change over time. My research interests thus range from investigating microorganisms under controlled laboratory conditions to the study of modern marine, lacustrine and terrestrial microbial communities and their role in global biogeochemical cycles and the interaction between geo- and biosphere over geological time scales.


A major focus of my current research is cyanobacteria. These microorganisms play a fundamental role in the modern global carbon and nitrogen cycles and are invoked to have played an important role in sustaining the high productivity that lead to repeated deposition of organic-rich sediments during e.g. Cretaceous Oceanic Anoxic Events and the deposition of Pleistocene sapropels of the Mediterranean. Understanding how cyanobacterial activity lead to the deposition of such organic-rich deposits is a key interest of my research.


Heterocystous cyanobacteria are a subgroup of the cyanobacterial lineage and play an important role in the cycling of nitrogen in fresh- and brackish waters. Under nitrogen-limited conditions may form massive blooms, known as harmful cyanobacterial blooms (cyanoHABs). Climate warming may lead to a significant proliferation of cyanoHABs in the future but how climate warming will promote the frequency and intensity of cyanoHABs and determine the community composition is large unknown. To study these blooms in the past, I employ novel biological marker, so-called heterocyst glycolipids (HGs), for which I developed a rapid screening technique using high performance liquid chromatography coupled to tandem mass spectrometry. Previous culture experiments have shown that the relative abundance of HGs shows a strong positive correlated with water temperature and in form of the HDI26 allows reconstructing modern and past lake surface water temperatures. The HDI and other HG-based indices may therefore provide novel lipid paleothermometers to study continental climate change, for which other organic temperature proxies such as the TEX86 or UK37 are not or only to some extend applicable. Closing this

Teaching in WS18/19



  • MNF-geow-B103-V: Biologie für die Geowissenschaften. Do. 16:15 – 17:47 Uhr, LMS12 – Hörsaal 7


  • MNF-geow-BWP07: Angewandte Marine Geochemie. Schiffsausfahrt (27.02.2019) und Laborpraktikum (04-08.03.2019)


  • MNF-geow-BWP012-01a: Organische Geochemie sedimantärer System, Mo. 8:30 - 10 Uhr, Di. 14:00 - 15.30 Uhr, LMS10 - Raum 157




  • MNF-geow-MWPS4: Biogeochemische Prozesse. Do. 12:00 – 13.30 Uhr, LMS10 – Raum 157

        Vorbesprechung zur Veranstaltung am Do.18.10.2018; Vorlesungsbeginn Do. 01.11.2018


  • MNF-geow-MWPS4: Paläoökosysteme. Mi. 8:00 – 9:00 Uhr, LMS10 – Raum 157


Please visit for more information regarding laboratory classes as well as lecture and seminar contents.


Running Projects

  • The role of diazotrophic cyanobacterial blooms in the expansion of bottom water hypoxia in the Baltic Sea since the last deglaciation

        DFG-funded project (see for                    details on the project). Bauersachs, T., Schwark, L.

  • Paleoclimate evolution of the NW-PAcific over the past 25 Ma

        DFG-funded project (see for                    details on the project). Bauersachs, T., Schwark, L.

  • Microbial diversity and processes in Red Sea brines (in cooperation with M. Schmidt, Geomar)
  • Distribution patterns of long chain diols in eustigmatophyte algae (in cooperation with the SAG culture collection)
  • Composition of Shark Bay microbial mats (in cooperation with K. Grice, Curtin University)

Completed Projects

  • Interplay of N2 fixation, anammox and denitrification in the Peruvian oxygen minimum zone (2017-2018)

        Future Ocean-funded project. Bauersachs, T.

  • Characterizing trophic links in pelagic ecosystems with stable isotope fingerprinting of amino acids (2015-2016)

        Future Ocean-funded project. Larsen, T., Bauersachs, T., Piatkowski, U., Andersen

  • Ocean floor hard-rock as a bioreactor (2015-2016)

         Future Ocean-funded project. Schwark, L., Schmitz-Streit, R.A., Devey, C.,                              Bauersachs, T.

  • Reconstruction of the variability of the Kuroshio Ocean Current (SE Japan) over the past 8 Ma (2012-2014)

        DFG-funded project (see for                   details on the project). Bauersachs, T.



Peer-reviewed publications

Publications in review

  • Schaefer, B., Grice, K.,, Coolen, M.J.L., Summons, R.E., Cui, X., Bauersachs, T., Schwark, L., Böttcher, M.E., Bralower, T.J., Lyons, S.L., Freeman, K.H., Cockell, C.S., Gulick, S.P.S., Morgan, J.V., Whalen, M.T., Lowery, C.M., Vajda, V. Microbial life in the nascent Chicxulub crater. Science Advances, in review
  • Bauersachs, T., Miller, S.R., Gugger, M., Mudimu, O., Friedl, T., Schwark, L. Heterocyst glycolipids indicate polyphyly of stigonematalean cyanobacteria. Phytochemistry, in review


  • Seguin, J., Bintliff, J.L., Grootes, P.M., Bauersachs, T., Dörfler, W., Heymann, C., Manning, S.W., Müller, S., Nadeau, M.J., Nelle, O., Steier, P., Weber, J., Wild, E.M., Zagana, E., Unkel, I. 2,500 years of anthropogenic and climatic landscape transformation in the Stymphalia polje, Greece. Quaternary Science Reviews, accepted for publication
  • Yao, Y., Zhao, J., Bauersachs, T., Huang, Y. Effect of water depth on the TEX86 temperature proxy in volcanic lakes of northeastern China. Organic Geochemistry 129, 88-98.


  • Baumann, L.M., Taubner, R.S., Bauersachs, T., Steiner, M., Schleper, C., Peckmann, J., Rittmann, K.M.R., Birgel, D. Intact polar lipids and core lipid inventory of the hydrothermal vent methanogens Methanocaldococcus villosus and Methanothermococcus okinawensis. Organic Geochemistry 126, 33-42.
  • Kars, M., Musgrave, R.J., Hoshino, T., Jonas, A.S., Bauersachs, T., Inagaki, F., Kodama, K. Magentic mineral diagenesis in a high temperature and deep methanic zone in Izu rear arc marine sediments, NW Pacific Ocean. Journal of Geophysical Research: Solid Earth 123, 8331-8348.
  • Warnock, J.P., Bauersachs, T., Kotthoff, U., Brandt, H.T., Andrén, E. Holocene history of the Ångermanälven Estuary. Boreas 47, 593-608.
  • Duda, J.P., Thiel, V., Bauersachs, T., Mißbach, H., Reinhardt, M., Schäfer, N., Van Kranendonk, M.J., Reitner, J. Ideas and perspectives: Hydrothermally driven redistribution and sequestration of early Archaean biomass - the ‘hydrothermal pump hypothesis‘. Biogeosciences 15, 1535-1548.
  • Papadomanolaki, N.M., Dijkstra, N., van Helmond, N.A.G.M., Hagens, M., Bauersachs, T., Kotthoff, U., Sangiorgi, F., Slomp, C.P. Controls on the onset and termination of past hypoxia in the Baltic Sea. Palaeogeography, Palaeoclimatology, Palaeoecology 490, 347-354.


  • Kotthoff, U., Groeneveld, J., Ash, J.L., Fanget, A.S., Quintana Krupinski, N., Peyron, O., Stepanova, A., Warnock, J., van Helmond, N.A.G.M., Passey, B.H., Clausen, O.R., Bennike, O., Andrén, E., Granoszewski, W., Andrén, T., Filipsson, H.L., Seidenkrantz, M.S., Slomp, C.P., Bauersachs, T. Reconstructing Holocene temperature and salinity variations in the western Baltic Sea region: A multi-proxy comparison from the Little Belt (IODP Expedition 347, Site M0059). Biogeosciences 14, 5607-5632.
  • Bauersachs, T., Talbot, H.M., Sidgwick, F., Sivonen, K., Schwark, L. Lipid biomarker signatures as tracers for harmful cyanobacterial blooms in the Baltic Sea. PLOS ONE 12, e0186360.
  • Weidenbach, K., Nickel, L., Neve, H., Alkhnbashi, O.S., Künzel, S., Krupczok, A., Bauersachs, T., Cassidy, L., Tholey, A., Backofen, R., Schmitz, R.A. MetSV, a novel archaeal lytic virus targeting Methanosarcina strains. Journal of Virology 91, e00955-17.
  • Kars, M., Musgrave, R.J., Kodama, K., Jonas, A.S.*, Bordiga, M., Ruebsam, W., Vautravers, M., Bauersachs, T. Impact of climate change on the magnetic mineral assemblage in marine sediments from Izu rear arc, NW Pacific Ocean, over the last 1 Myr. Palaeogeography, Palaeoclimatology, Palaeoecology 480, 53-69.
  • Jonas, A.S.*, Schwark, L., Bauersachs, T. Late Quaternary water temperature variations of the Northwest Pacific based on the lipid paleothermometers TEXH86, UK’37 and LDI. Deep Sea Research I 125, 81-93.




  • Zink, K.G., Vandergoes, M.J., Bauersachs, T., Newnham, R., Schwark, L. A refined paleotemperature calibration for New Zealand limnic environments using differentiation of branched glycerol dialkyl glycerol tetraether (brGDGT) sources. Journal of Quaternary Science 31, 823-835.


  • Mueller-Niggemann, C., Utami, S.R., Marxen, A., Mangelsdorf, K., Bauersachs, T., Schwark, L. Distribution of tetraether lipids in agricultural soils – differentiation between paddy and upland management. Biogeosciences 13, 1647-1667.


  • Bauersachs, T., Schwark, L. Glycerol monoalkanediol diethers: A novel series of archaeal lipids detected in hydrothermal environments. Rapid Communications in Mass Spectrometry 30, 54-60.




  • Bauersachs, T., Rochelmeier, J., Schwark, L. Seasonal lake surface water temperature trends reflected by heterocyst glycolipid based molecular thermometers. Biogeoscienes 12, 3741-3751.


  • Heyng, A.M., Mayr, C., Lücke, A., Moschen, R., Wissel, H., Striewski, B., Bauersachs, T. Middle and Late Holocene paleotemperatures reconstructed from oxygen isotopes and GDGTs of sediments from Lake Pupuke, New Zealand. Quaternary International 374, 3-14.


  • Bauersachs, T., Weidenbach, K., Schmitz, R.A., Schwark, L. Distribution of glycerol ether lipids in halophilic, methanogenic and hyperthermophilic archaea. Organic Geochemistry 83-84, 101-108.


  • Mudimu, O., Rybalka, N., Bauersachs, T., Friedl, T., Schulz, R. Influence of different CO2 concentrations on microalgae growth rate, α-tocopherol content and fatty acid composition. Geomicrobiology Journal 32, 291-303.


  • Andrén, T., Barker Jørgensen, B., Cotterill, C., Green, S., Andrén, E., Ash, J., Bauersachs, T., Cragg, B., Fanget, A.S., Fehr, A., Granoszewski, W., Groeneveld, J., Hardisty, D., Herrero-Bervera, E., Hyttinen, O., Jensen, J.B., Johnson, S., Kenzler, M., Kotilainen, A., Kotthoff, U., Marshall, I.P.G., Martin, E., Obrochta, S., Passchier, S., Quintana Krupinski, N., Ridinger, N., Slomp, C., Snowball, I., Stepanova, A., Strano, S., Torti, A., Warnock, J., Xiao, N., Zhang, R. IODP expedition 347: Baltic Sea basin paleoenvironment and biosphere. Scientific Drilling 20, 1-12.




  • Bauersachs, T., Schouten, S., Schwark, L. Characterization of the sedimentary organic matter preserved in the Messel oil shale by bulk geochemistry and stable isotopes. Palaeogeography, Palaeoclimatology, Palaeoecology 410, 390-400.


  • Mudimu, O., Rybalka, N., Bauersachs, T., Born, J., Friedl, T., Schulz, R. Biotechnological screening of microalgal and cyanobacterial strains for biogas production and antibacterial and antifungal effects. Metabolites 4, 373-393.


  • Bauersachs, T., Stal, L., Grego, M., Schwark, L. Temperature dependency of the distribution of heterocyst glycolipids in N2-fixing heterocystous cyanobacteria. Organic Geochemistry 69, 98-105.


  • Bauersachs, T., Mudimu, O., Schulz, R., Schwark, L. Distribution of long chain heterocyst glycolipids in N2-fixing cyanobacteria of the order Stigonematales. Phytochemistry 98,145-150.




  • Schouten, S., Hopmans, E.C., Rosell-Melé, A., Pearson, A., Bauersachs, T., et. al. An interlaboratory study of TEX86 and BIT analysis of sediments, extracts and standard mixtures. Geochemistry, Geophysics, Geosystems 14, 5263-5285.


  • Bauersachs, T., Miller, S., Hopmans, E.C., van der Meer, M.J.T., Schouten, S., Sinninghe Damsté, J.S. Distribution of long chain heterocyst glycolipids in cultures of the thermophilic cyanobacterium Mastigocladus laminosus and a hot spring microbial mat. Organic Geochemistry 56, 19-24.




  • Henry, P., Kanamatsu, T., Thu Moe, K., Strasser, M., Alves, T., Bauersachs, T., Daigle, H., Ekinci, K., Gao, S., Garcon, M., Kawamura, K., Kitamura, Y., Sverre Laberg, J., Lee, G., Lee, Y., Lu, Y., Marcaillou, B., Matsubayashi, O., Nagahashi, Y., Novak, B., Saito, Y., Satoguchi, Y., Screaton, E.J., Scudder, R.P., Ra Song, B., Yamaguchi, A. IODP Expedition 333: Return to Nankai Trough subduction inputs sites and coring of mass transport deposits. Scientific Drilling 14, 4-17.




  • Bauersachs, T., Compaoré, J., Severin, I., Hopmans, E.C., Stal, L.J., Schouten, S.,  Sinninghe Damsté, J.S. Diazotrophic microbial community of coastal microbial mats of the southern North Sea. Geobiology 9, 349-359.


  • Kim, J.H., Talbot, H.M., Zarzycka, B., Bauersachs, T., Wagner, T.. Occurrence and abundance of soil-specific bacterial membrane lipid markers in the Têt watershed (Southern France): Soil-specific BHPs and branched GDGTs. Geochemistry, Geophysics, Geosystems 12, 1-15.




  • Bauersachs, T., Speelman, E.N., Hopmans, E.C., Reichert, G.J., Schouten, S., Sinninghe Damsté, J.S. Fossilized glycolipids reveal past oceanic N2 fixation by heterocystous cyanobacteria. Proceedings of the National Academy of Science USA (PNAS) 107, 19190-19194.


  • Bauersachs, T., Schouten, S., Compaoré, J., Stal, L.J., Sinninghe Damsté, J.S. Occurrence of C35-C45 polyprenols in filamentous and unicellular cyanobacteria. Organic Geochemistry 41, 867-870.




  • Bauersachs, T., Compaoré, J., Hopmans, E.C., Stal, L.J., Schouten, S., Sinninghe Damsté, J.S. Distribution of heterocyst glycolipids in cyanobacteria. Phytochemistry 70, 2034-2039.


  • Bauersachs, T., Hopmans, E.C., Compaoré, J., Stal, L.J., Schouten, S., Sinninghe Damsté, J.S. Rapid analysis of long-chain glycolipids in heterocystous cyanobacteria using high-performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry. Rapid Communications in Mass Spectrometry 23, 1387-1394.


  • Bauersachs, T., Schouten, S., Compaoré, J., Wollenzien, U., Stal, L.J., Sinninghe Damsté, J.S. Nitrogen isotopic fractionation associated with growth on dinitrogen gas and nitrate by cyanobacteria. Limnology and Oceanography 54, 1403-1411.
  • Bauersachs, T., Schouten, S., Sinninghe Damsté, J.S., Kremer, B. A biomarker and δ15N study of thermally altered Silurian cyanobacterial mats. Organic Geochemistry 40, 149-157.