The focus at EML is on microbiology with numerous projects dedicated to geomicrobiology – the study of the role of microbes in geochemical processes – and a growing number of projects focused on gut microbiology.
The focus at EML is on microbiology with numerous projects dedicated to geomicrobiology – the study of the role of microbes in geochemical processes – and a growing number of projects focused on gut microbiology. Research interests combine fundamental investigations of molecular-scale microbial processes that transform metals and field-based research to further our understanding of the role of microbes in contaminant mobility in the environment. Applications include the remediation of metal-contaminated field sites, elucidating the role of microbes in nuclear waste repository stability, and the study of biogeochemical cycling in pristine environments.
To characterize laboratory and field systems, we employ techniques ranging from synchrotron-based spectroscopy and microscopy (XAS, µXAS, STXM), electron microscopy (STEM, HRTEM, cryo-EM), microbial community analyses (pyrosequencing of 16S rRNA, metagenomics, metaproteomics and metatranscriptomics), and geochemical and mineralogical characterizations (ICP-MS, XRD, SAED). More recently, isotopic tools, particularly pertaining to uranium, carbon, sulfur, iron and nitrogen have been added to the panoply of the lab and are primarilry used to identify biological processes.
In addition to using a rich combination of techniques and approaches, we also probe systems at a variety of scales. Our work ranges from characterization of the binding environment of metals (at the nanometer scale) to the study of biological processes in the field (at the meter scale).
The aim of this multi-scale, multi-disciplinary approach is to construct a coherent picture of geomicrobiological processes by integrating information gathered at the various scales and through the various techniques. The ultimate goal is to translate laboratory results to the field to inform bioremediation technologies, further our understanding of fundamental biogeochemical cycles, identify processes that control the mobility of contaminants as well as to help assess the safety case of geological nuclear waste repositories. Further applications, particularly of the isotope work, include probing the rock record for evidence of early life.
The gut microbiology component of the laboratory focuses on the transformation of the bile acids by commensal organisms in the gut. Our particular interest is the 7-dehydroxylation of bile acids that is catalyzed by a specific group of bacteria in large intestine. This bile acid transformation has implications for Clostridium difficile infection as well as a range of human intestinal tract diseases.
New paper in Environmental Science & Technology
Congratulations to Karen Viacava for her paper on "Variability in Arsenic Methylation Efficiency across Aerobic andAnaerobic Microorganisms".
Uranium reveals its true nature
EPFL scientists have made a significant discovery in how nanoscale minerals form naturally, including the way in which they transition from a soluble to a solid state. Their findings could be used to inform radioactive waste management.