An Investigation to Corroborate Volatile and Biological Profiles of Human Odor for Forensic Subject Identification

Authors

Chantrell J.G. Frazier, Florida International UniversityFollow

Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Biochemistry

First Advisor's Name

Dr. Kenneth G. Furton

First Advisor's Committee Title

Co-Committee Chair

Second Advisor's Name

Dr. DeEtta K. Mills

Second Advisor's Committee Title

Co-Committee Chair

Third Advisor's Name

Dr. Justin Carmel

Third Advisor's Committee Title

Committee member

Fourth Advisor's Name

Dr. Yuk-Ching Tse-Dinh

Fourth Advisor's Committee Title

Committee member

Fifth Advisor's Name

Dr. Lou Kim

Fifth Advisor's Committee Title

Committee member

Keywords

Volatile Organic Compounds (VOCs), Microbiome, Forensic Identification, Human Odor, Headspace Solid phase microextraction (HS-SPME), Gas chromatography mass spectrometry (GCMS), 16S rDNA gene, Next generation sequencing (NGS)

Date of Defense

3-30-2022

Abstract

Hands are an integral part in transferring complex microbial communities to and from our surroundings. As a result, hands are significant in provenance investigations as specific microbiota can be deposited on everyday objects through touch interactions. Skin microbiome, including bacteria, fungi, and viruses, are unique to each person, and this ‘uniqueness’ can be exploited and applied to forensic identification. Skin microbiota and volatile organic compounds (VOCs) are closely related due to specific bacteria breaking down non-volatile organic compounds to volatile organic compounds that are characteristically present in human scent. However, analyses of microbiota from touch interactions have proven to be difficult due to the low levels of genomic DNA (gDNA) that can be collected and analyzed with downstream techniques.

Headspace Solid Phase Microextraction Gas Chromatography Mass Spectrometry (HS-SPME-GCMS) is commonly used to conduct VOC analyses of air and water samples. However, previous studies have utilized HS-SPME-GCMS as a forensic approach to examine VOCs exuded from various regions of the body as a form of identification. Furthermore, the human microbiome has been closely studied in relation to health and disease, but more recently been examined as new potential forensic tool. The objective of this research is to analyze samples collected from subject’s palms to determine the relationship between the bacterial microbiota profile and the VOC profile as it relates to the classification and discrimination of individuals. Palmar sweat samples and epithelial swabs were simultaneously collected for VOC and microbiome analysis, respectively. Supervised linear regression models (PLS-DA, OPLS-DA, and LDA) were evaluated as a tool for the prediction and discrimination of subject gender. The amplified DNA targeting the V1-V2 16S rDNA region was initially screened via Length Heterogeneity Polymerase Chain Reaction (LH-PCR) to obtain an initial assessment of the bacterial community’s diversity. Amplicons were sequenced with Next Generation Sequencing (NGS) technology and further analyzed with bioinformatics, which identified well known skin bacterium on the genus level Staphylococcus, Cutibacterium, Enhydrobacter, Streptococcus, Lawsonella, Fusobacterium, and Micrococcus. The combination of human odor and bacterial microbiome analysis could lead to the utilization of odor as a novel biometric for forensic identification where other physical and trace evidence may be lacking.

Identifier

FIDC010504

ORCID

0000-0003-0838-0530

Recommended Citation

Frazier, Chantrell J.G., "An Investigation to Corroborate Volatile and Biological Profiles of Human Odor for Forensic Subject Identification" (2022). FIU Electronic Theses and Dissertations. 4919.
https://digitalcommons.fiu.edu/etd/4919