Isotopic compositions of archaeal membrane lipids in methanogenic sediments

Abstract

A significant contribution of Methanogenic archaea (methanogens) on methanogenesis in marine subsurface sediments has been suggested on the basis of isotopic compositions of methane from sediments and gas hydrate water lattice. However, habitats and activities of methanogens are still unknown. Lipid biomarkers and their isotope analyses can be useful tools to study distribution of methanogens in marine sediment because their unique metabolism is reflected in carbon isotope compositions of their membrane lipids. The techniques to detect methanogens and their membrane lipid analysis are more recently developed and are applied to gas hydrate bearing marine sediments, and a new approach of function specific compound analysis is suggested.