Changes to soil bacterial profiles as a result of Sus scrofa domesticus decomposition

• Bacterial diversity and richness changed due to Sus scrofa domesticus decomposition.
• Temporal and spatial community shifts evidenced relative to buried material.
• Shifts linked also to temporal changes in taphonomic and environmental parameters.
• DGGE can potentially become another forensic tool for clandestine grave location.
• Applicability potential may be tested/advanced with in situ studies and sequencing.

The importance of cadaver decomposition knowledge for clandestine grave location cannot be over emphasised. Notwithstanding this, only a limited understanding is available on the resulting soil microbial community dynamics. To address this paucity, a pig leg (Sus scrofa domesticus; 5 kg) was buried in freshly weighed (20 kg) sandy loamy soil in a sealed microcosm (40 cm height) in parallel with a soil only control. Both microcosms were perforated nine times at equal distances and maintained outside. Soil samples were collected through these perforations from the top (0–10 cm), middle (10–20 cm) and bottom (20–30 cm) segments every three days for the first two weeks, and then weekly up to 14 weeks. PCR-DGGE gels quantified by 1D Phoretix showed increases in the cumulative soil community richness values of 43, 66 and 106 for the top, middle and bottom segments, respectively, in the presence of Sus scrofa domesticus. Shannon–Wiener's (H′) and Simpon's (D) indices confirmed corresponding species diversity increases in the middle (H′ = 1.58–2.33; D = 0.79–0.91) and bottom (H′ = 2.48–3.16; D = 0.85–0.95) depths between days 10 and 71 compared with the control. In contrast, similar evenness was recorded for all segments in both the Sus scrofa domesticus and control soils.