Microorganisms control most of the global biogeochemical cycles necessary to sustain life. Iron minerals especially dominate the solid phase of porous media and their redox cycling supports key biogeochemical processes, which influence the fate of organic matter or contaminant elements. Based on my interdisciplinary background, my research group is focused on the microbial processes and biogeochemistry of a variety of ecosystems from freshwater lakes and sediments, peatlands, and both pristine and heavy metal contaminated streams and aquifers. We use both molecular and cultivation-based techniques to unravel the structure/function relationships of the inherent microbial communities.