We are currently studying the localization of microbes by apatite (calcium phosphate). A specific question is the role of microbial uptake of phosphorus and excretion of metabolic byproducts in solubilization of otherwise insoluble secondary phosphates that limit the fertility of some soils.

This image shows numerous cells associated with apatite and secondary phosphates in weathered granite. The image below shows the distribution of microorganisms. The cells are visualized by staining their DNA with a fluorescent dye (DAPI).