The ubiquitous nature of microorganisms and their specificity to certain locations make them potentially useful for forensic investigators. Advances in microbial profiling techniques have made it possible to compare microbial community profiles obtained from evidence or crime scenes to individuals and vice versa. Profiling microbial communities associated with cadaver decomposition may provide useful information concerning post-mortem intervals and aid in the identification of clandestine graves. Four experiments using pigs as human decomposition analogues were performed over the course of 2011 and 2012 in southern Ontario to document changes in soil microbiology following decomposition. Studies were conducted in the spring and summer to document the effect of environmental conditions on the decomposition process and subsequent changes in gravesoil microbiology. Microbial activity was measured using a fluorescein diacetate assay as a preliminary indicator of changes within the soil microbial population. Both decreases and increases in microbial activity were observed throughout each decomposition experiment indicating that the microbial response to decomposition is complex. It is believed that environmental conditions and decomposition rates play a role in determining how taphonomic events affect soil microbial activity. Fatty acid methyl esters (FAME) profiling was used document community level changes throughout decomposition. Shifts in FAMEs profiles were brought on by the onset of active decay and persisted through to the dry remains stage. The fatty acids 3OH 12:0, 12:0, 16:0 and 18:0 were frequently found in higher amounts in gravesoils and may prove useful as markers of cadaver decomposition. Metagenomic profiles of soil microbial communities were obtained using Illumina?? sequencing. Decomposition was associated with changes v in microbial community composition. This allowed gravesoil samples to be differentiated from control samples for an extended period of time. Bacteria responsible for the shift in microbial profiles are those commonly associated with cadaver decomposition. Both sets of soil profiles indicated that weather had an effect on microbial community composition. Results highlight the need to document natural changes in microbial communities over seasons and years to establish normal microbial patterns to effectively use soil microbial profiles as post-mortem interval or clandestine grave indicators.

Traditional fecal indicator bacteria such as fecal coliform, E.coli and enterococci have been shown to be unreliable indicators of the hygienic quality of recreational waters under tropical conditions. One of the major reasons for considering these bacteria as ineffective indicators of water quality in warm, tropical regions is that they are consistently found in natural environments (plants, soil, water) in the absence of any significant contamination of these environments. Since preliminary studies conducted in Hawaii had indicated soil as the major environmental source of elevated concentrations of these bacteria in environmental waters, the aim of this study was to focus on the soil environment to specifically address two assumptions made by regulatory agencies in using fecal bacteria as indicators of water quality: first, there should not be an environmental source of these indicator bacteria unrelated to sewage or fecal matter contamination, and second, the indicator bacteria do not multiply in the environment. To determine the validity of these two assumptions under tropical conditions in Hawaii and possibly other tropical locations, various experiments were conducted. The major findings are as follows. 1) Analysis of soil samples collected from various locations representing major soil groups on the island of Oahu showed that fecal indicator bacteria are naturally found in most of the soil environments, indicating that the fecal bacteria have adapted to the soil conditions to become part of soil biota. 2) Evidence was obtained to show that the soil contains adequate nutrients to sustain the populations of these bacteria. 3) Growth and multiplication of fecal indicator bacteria in natural soil was dependent on available nutrients (particularly carbon), moisture and competing microorganisms. In conclusion, tropical soil conditions are suboptimal for the multiplication of fecal indicator bacteria. Consequently, these bacteria in natural soil conditions will probably grow and multiply sporadically when conditions are relatively optimal. Although concentrations of fecal indicator bacteria in soil represent only a small fraction of the microbiota, their counts are significant enough in numbers not only to impact the quality of recreational waters but also to nullify two of the assumptions used in the application of recreational water quality standards. Thus, there is a need for an alternate and more reliable indicator of water quality in Hawaii and other tropical locations. / Department of Health, State of Hawaii; US Environmental Protection Agency

Thesis (M.Ag.Sc.)--University of Adelaide, Dept. of Soil and Water, Waite Agricultural Research Institute, 2000. / Bibliography: leaves 116-127.

Thesis (Ph.D.) -- University of Adelaide, Dept. of Agronomy and Farming Systems, 2002. / "September 2001" Includes bibliographical references (leaves 206-230).

Thesis (Ph.D.)--University of Western Australia, 2007.

Thesis (M.S.) in Plant, Soil and Environmental Sciences--University of Maine, 2008. / Includes vita. Includes bibliographical references (leaves 88-93).

Thesis (M.Sc.) - Carleton University, 2003. / Includes bibliographical references (p. 108-126). Also available in electronic format on the Internet.

Thesis (M. App. Sc.)--Carleton University, 2004. / Includes bibliographical references (p. 117-123). Also available in electronic format on the Internet.

Thesis (M.S.)--Michigan State University. Dept. of Microbiology & Molecular Genetics, 2008. / Title from PDF t.p. (viewed on July 29, 2009) Includes bibliographical references (p. 162-166). Also issued in print.

Thesis (Ph. D.) -- Lincoln University, 2009. / Also available via the World Wide Web.