Microbial community assembly and metabolic function during mammalian corpse decomposition

TLDR

Vertebrate corpse decomposition is a key stage in terrestrial nutrient cycling, yet the microbially mediated processes remain poorly understood. The study aims to elucidate the principles governing microbial community assembly during mouse and human corpse decomposition on different soil substrates. We combined deep microbial community characterization, community‑level metabolic reconstruction, and soil biogeochemical assessment. We identified bacterial and fungal groups involved in nitrogen cycling, a reproducible decomposer network that emerges on predictable time scales, and found that the community originates mainly from bulk soil with key decomposers present in low abundance, that soil type does not dominate community development, and that the reproducible process offers new forensic opportunities.

Abstract

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 the 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 that contribute to nitrogen cycling and a reproducible network of decomposers that emerge on predictable time scales. Our results show that 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 to offer new opportunities for forensic investigations.