Metcalf_Carter_decomposing_pig_soils_18S. Seasonal variation of postmortem microbial communities

We recently showed that corpse-associated microbes provide a reliable clock of ecological succession that can be used to estimate post-mortem interval (PMI) accurately under laboratory conditions using a rodent model. In this update, we extend the work to larger mammals (swine) under field conditions. We demonstrate that this larger mammalian model also decomposes in a specific, reproducible fashion, and that soil-borne microbes contribute substantially to the gravesoil microbial community of the decomposing corpse. However, the effects on soil microbial communities are season-specific. The results suggest that the microbial clock of ecological succession may be useful in human forensic settings, although measurements at different times of year and under different soil conditions will be required in order to support decisions in the courtroom.

本研究团队此前已证实，尸体关联微生物可作为可靠的生态演替时钟，在实验室环境中借助啮齿动物模型，能够精准估算死后间隔时间（post-mortem interval, PMI）。本研究在此基础上，将实验拓展至野外条件下的大型哺乳动物（猪，swine）模型。研究结果表明，该大型哺乳动物模型同样会以特定且可重复的模式发生腐败，且土壤源微生物对腐败尸体的墓土微生物群落具有显著贡献。但该效应对土壤微生物群落的影响存在季节特异性。本研究结果显示，基于生态演替的微生物时钟可应用于人类法医鉴定场景，不过为支撑法庭裁决，仍需开展不同季节与不同土壤条件下的相关测量工作。