Microbial Transformations of Minerals and Metals: Recent Advances in Geomicrobiology Derived from Synchrotron-Based X-Ray Spectroscopy and X-Ray Microscopy

The field of geomicrobiology has embraced efforts to define and quantify the role of microbial organisms in low-temperature geochemical processes. However, any mechanistic understanding of the interactions between microbial organisms and minerals or metals requires analytical tools with the appropriate chemical sensitivity and spatial resolution. In the past several years, increasing application of nanometer-, micron-, and bulk-scale synchrotron-based X-ray techniques has provided new insights regarding the feedbacks among microbial growth, mineral dissolution, redox transformations, and biomineralization processes. In this review, recent findings derived from X-ray absorption spectroscopy, X-ray microprobe mapping, and X-ray microscopy studies are integrated to provide a new view of the dynamic biogeochemistry occurring at the microbe-mineral interface.