Rainer U. Meckenstock

We investigate limitations of microbial degradation of contaminants in the environment with the main question: “how are environmental contaminants degraded and why are they sometimes not?” Our model system is the anaerobic degradation of Polycyclic Aromatic Hydrocarbons (PAHs). PAHs are ubiquitous and hazardous contaminants and are extremely slowly degraded in anoxic environments. We study the fate of PAHs from the ecology of the degradation processes over the physiology of isolated microorganisms to the biochemistry of the degradation pathways. We discovered novel ecological principles such as microbial life in small water droplets enclosed in oil as well as novel enzymes and biochemical reactions in the anaerobic degradation pathways of naphthalene and phenanthrene. Our study habitats of interest are groundwater, oil reservoirs, and rivers. The knowledge on the degradation processes is contributing to protecting our most important resource for life, clean water and environment, and to foster our understanding about microbial processes in the subsurface, the biggest habitat on earth but also the least investigated. Furthermore, we perform ecological studies on rivers where we study the microbial degradation of dissolved organic carbon (DOC) and dead microorganisms (necromass) as important parts of the microbial loop which recycles organic matter.