Using quantitative stable isotope probing to characterize the functional ecology of microbial phylogenetic groups

With such a great diversity of microorganisms in natural habitats such as soil, it is hard to determine if or how community composition influences ecosystem processes. Using a new technique, quantitative stable isotope probing (qSIP), we are beginning to quantitatively measure microbial activity. To date our results suggest that in situ microbial activity exhibits strong phylogenetic organization with distinct activity patterns among phylogenetic groups. This organization extends to relatively ubiquitous functions, for which community members have previously been considered functionally redundant, paving the way to make meaningful connections between microbial community structure and function.