Universal microbial network decomposes mammals despite varied climate, location, and seasonal influence

Microbial breakdown of organic material is one of the most important processes on earth, yet enormous knowledge gaps exist about its controls. We demonstrate that a universal, inter-kingdom microbial network assembles in response to nutrient-rich, terrestrial mammalian decomposition, despite selection effects of location, climate and season. We created the first metagenome-assembled genome library from mammalian decomposition-associated soils and combined it with metabolomics to identify a microbial decomposer network that interacts by cross-feeding to efficiently metabolize labile decomposition products. The key fungal and bacterial decomposers appear unique to the breakdown of terrestrial cadavers, and are rare in relative abundance across non-decomposition environments. Blow flies are suggested as an important decomposer vector and the observed lockstep of microbial interactions underlies a robust microbial forensic tool for predicting the time since death.