ADVANCING MICROBIAL METABOLOMICS: UNTARGETED LC-MS/MS ANALYSIS FOR INFECTIOUS DISEASE AND NATURAL PRODUCT LIBRARIES

Abstract

Metabolomics is the study of small molecules, often within a biological system. Metabolites, defined as molecules with less than 1500 Da, provide snapshots of the end result of multiple, overlapping biological processes. Among the available instrumental methods which can be used for metabolomics research, mass spectrometry is particularly powerful. Mass spectrometry has the ability to simultaneously detect thousands of metabolites and generate spectra that support both qualitative and quantitative analysis. This enables broad characterization of the entire metabolome and facilitates a wide range of applications. Mass spectrometry-based metabolomics can be applied to study disease-associated metabolic shifts, discover potential biomarkers, identify novel natural products, and explore patterns of chemical diversity. However, the scale and complexity of these datasets present significant analytical and statistical challenges that must be carefully addressed in new applications. In this dissertation, I apply mass spectrometry-based metabolomics to address diverse questions in microbial science, with each project highlighting a distinct application of this approach. Each project demonstrates a new application for this untargeted metabolomics. In my first chapter, I developed a novel method to research small molecules in a chronic wound context. For my second and third chapters, I applied metabolomics to optimize fungal natural product library design for bioactive drug discovery. In chapter two, I did this by generating a method to rationally minimize a large extract collection. In chapter three, I performed a meta-analysis on a large collection of fungi to examine how different factors like culturing conditions, geographical origin, and morphology relate to overall diversity of fungal extracts. Collectively, this dissertation broadens the application for untargeted mass spectrometry.