Molecular Geochemistry

After a brief introduction to organic (geo)chemistry, this lecture will center around lipid biomarkers as indicators of active biogeochemical processes in marine sediments. We will define molecular biomarker classes and their isotope signatures associated with the turnover of different organic matter types (i.e. substrates) and interrrelate those with the cycling of C, N, S, Mn and Fe. Specifically, we will discuss recent applications ranging in space from the ocean surface down to the deep biosphere.

At the end of this course the student will be able to:
a) utilize biomolecules as sources of information for the study of biogeochemical processes.
b) interpret the functional relationships between microbially driven carbon cycling and molecular signatures.
c) understand the adaptations of sedimentary microbes to environmental factors using lipid biomarkers.

Oral exam focusing on all three course topics offered in the module (30 min).

oral exam

Killops & Killops (2005) Introduction to organic geochemistry, 2nd edition.
Peters, Walters and Moldowan (2005) The biomarker guide, 2nd edition.

1st SWS: General introduction of the course topic Molecular Geochemistry
2nd SWS: The complexity of organic molecules (membrane lipid layers, biosynthesis, substrate specificity)
3rd SWS: Isotope signatures of organic molecules (substrate specificity, fractionation, fixation pathways)
4th SWS: Molecular signatures of photoautotrophy and associated heterotrophy
5th SWS: Microbial lipids of ammonium-oxidizing microorganisms
6th SWS: Microbial lipids of iron- and sulfate-reducing microorganisms I
7th SWS: Microbial lipids of iron- and sulfate-reducing microorganisms II
8th SWS: Teaching day
9th SWS: Molecular signatures of methanogens and methanotrophs
10th SWS: Molecular isotope signatures in the anaerobic oxidation of methane
11th SWS: Deep Biosphere - Introduction
12th SWS: Deep Biosphere - IODP Expedition 337
13th SWS: Lipids of the deep biosphere I
14th SWS: Lipids of the deep biosphere II