|Authors||Macdonald, L.M., Singh, B.K., Thomas, N., Brewer, M.J., Campbell, C.D. and Dawson, L.A.|
|Publication details||Journal of Applied Microbiology 105, 813-821.|
|Keywords||archaea, bacteria, forensic evidence, fungi, soil archive, soil drying.|
Aims: To evaluate: (i) the impact of air-drying on bacterial, archaeal and fungal soil DNA profiles and (ii) the potential use of multiplex-terminal restriction fragment length polymorphism (M-TRFLP) as a tool for forensic comparison of soil.
Methods and Results: An M-TRFLP approach was used to profile bacterial, archaeal and fungal DNA profiles from five different soil sites. Air-drying soil significantly reduced the quantity of DNA but the number of operational taxanomic units (OTU) was unaffected. The impact of air-drying on soil DNA profiles was dependent on soil site and microbial primers. Fungal profiles were altered the least by air-drying. For prokaryotic profiles, air-drying altered the relative similarity / dissimilarity between soil sites. The M-TRFLP approach was more discriminatory compared with soil colour and single-taxa profiling, but did not significantly improve resolution between two similar soils.
Conclusions: Of those tested, soil fungi were potentially the more robust target for application to soil forensic studies as they were altered less by air-drying and provided clear discrimination of soils from different sites. The M-TRFLP method demonstrated potential to achieve greater resolution, discriminating the soil sites based on both bacterial and fungal components.
Significance and Impact of the Study: Soil DNA profiling has potential as a forensic tool, but sample condition and the appropriate selection of microbial target taxa must be considered.