Plastifying marine microhabitats -exploring biogeochemical processes in microscale

Abstract

It is essential for understanding biogeochemical processes in sediments to work with virtually undisturbed samples in scales as small as possible, ideally to those scales where the processes take place. To maintain spatial structure and study microorganisms and mineral constituents in high resolution sediment samples were plastified with Glycolmethacrylate (GMA), a water permeable polyester. Special efforts were paid to minimize changes in biological, chemical and physical disturbance during the preparation. Impregnating sediments and microbial mats with GMA enabled characterization of the sediment structure (2D arrangement of particles), and analysis of elemental composition of matrix background and individual particles. Insights in spatial distribution of microorganisms were derived by identifying microorganisms in embedded undisturbed sediment samples adopting staining and fluorescence in situ hybridization (FISH) protocols.