Microbial community assembly and metabolic function during mammalian corpse decomposition

 Vertebrate corpse decomposition provides an important stage in nutrient cycling in most terrestrial habitats, yet microbially-mediated processes are poorly understood. Here we combine deep microbial community characterization, community-level metabolic reconstruction, and soil biogeochemical assessment to understand principles governing microbial community assembly during decomposition of mouse and human corpses on different soil substrates. We find a suite of bacterial and fungal groups contributing to nitrogen cycling and a reproducible network of decomposers that emerge on predictable timescales. The results show this decomposer community is derived primarily from bulk soil, but key decomposers are ubiquitous in low abundance. Soil type was not a dominant factor driving community development and the process of decomposition is sufficiently reproducible that it offers unique opportunities for forensic investigations.