D3018: Seasonal microbial succession in beetles and soil during carrion decomposition

Monday, November 11, 2024

9:00 AM – 5:00 PM MST

Location: Phoenix Convention Center, Exhibit Hall 6, PCC

Presenting Author(s)

KW

Kelly Waters

Graduate Student
Michigan State University
East Lansing, Michigan

Co-Author(s)

AG

Anthony Grigsby

Michigan State University
East Lansing, Michigan
BM

Bethany Mikles

Michigan State University
East Lansing, Michigan
Jennifer Pechal

Assistant Professor
Michigan State University
East Lansing, Michigan
MB

M. Eric Benbow

Professor
Michigan State University
East Lansing, Michigan

When carrion decomposes outdoors, decomposition fluid and organic material are introduced into the soil beneath the carcass, thus altering the microbial communities over time. Several families of beetles interact with this soil while feeding on the carcass or fly larvae, altering their internal microbiome. As part of a seasonal decomposition study, beetles and soil samples were collected underneath replicate stillborn swine carcasses throughout decomposition to investigate differences in bacterial community successional change during the spring, summer, and fall seasons of one calendar year. DNA was extracted from all samples and sequenced using 16S amplicon based high-throughput sequencing. The resulting data were assembled, quality-filtered, and analyzed with the QIIME2 software. During each season, the soil communities significantly changed across time points consistent with trajectories that have been previously reported in other studies of carrion and human cadaver decomposition, but the taxa and rate of change were different among seasons. During the beginning stages of decomposition, Firmicutes is reported to be the most dominant bacterial phyla of soil communities but is then replaced by Proteobacteria as decomposition progresses. All soil samples from underneath the carcasses had communities that were also significantly different from control soil samples. Analysis is ongoing to identify the succession of bacteria in beetle internal microbiomes and how this relates to soil community structure during decomposition. These data demonstrate predictable differences in the soil microbial communities at varying time points during decomposition which could allow for future reliable microbiome-based postmortem interval estimate using bacterial communities.