Only recently discovered, the biosphere in deeply buried marine sediments harbors an enormous ecosystem of previously hidden prokaryotic life forms. Although this deep biosphere contains 10 to 30% of the total surface biosphere biomass still little is known about the key processes and their linkage to the overlying ocean. In IODP, the exploration of the Deep Biosphere is now one of the major research themes. Major questions of the deep biosphere research initiative include:
What types of microbes thrive in deeply buried sediments and what are the processes they are mediating?
What impact does this biosphere have on the Earth's surface and on global element cycling?
To adress these important questions I analyzed membrane lipids with
HPLC/MSn for structure elucidation
GC/MS for identification of additional properties like headgroups/ether alkyl chains/fatty acids and for quantification
GC/IRMS to determine the carbon stable isotope ratio