Micron-scale resolution of sulfur cycling in a microbial mat

Microbial mats consist of finely laminated layers of diverse microbial communities. Mat organization is thought to result from strong spatial gradients in light intensity and redox in the uppermost few millimeters Optical examination reveals microbial laminations on scales between 5mm and 5um throughout the thickness of the microbial mat. However, such fine laminations at depth have usually been regarded as a 'relict architecture' inherited from an older mat surface. To further our understanding of microbial processes within this laminated architecture, we have investigated sulfur cycling (as recorded by sulfide production) within a benthic microbial mat.