Environmental Chemistry of Biomolecules

Abstract

This habilitation thesis entitled “Environmental Chemistry of Biomolecules” focusses on determining chemical information to evaluate water quality and to protect human health and ecosystem functioning. Such knowledge is crucial for public authorities to manage water resources especially as we are facing growing inputs of bioactive chemicals with adverse environmental effects. My work is rooted in environmental and analytical chemistry of aquatic enzymes, natural toxins, and micropollutants. I investigate the environmental behavior of these molecules to define the exposure side of human and ecological risk assessment. My team has built an expertise for analytical solutions to study site-specific damage of biomolecules of varied complexity. My aim is to elucidate how long-lived these biomolecules are in environmental and engineered systems. Therefore, we study transformation processes with a particular focus on photochemical and enzymatic reactions. Presented is a cumulative thesis in accordance with the current regulation in the Department of Environmental Systems Science at ETH Zürich. The thesis is structured in three parts: In chapter 1, I highlight the impact of daylight on the environmental chemistry of biomolecules emphasizing some of my contributions. In chapter 2-5, I present detailed studies of each focus area: photochemical transformation of micropollutants (chapter 2), photochemical transformation of enzymes and their building blocks (chapter 3), diversity of bioactive and toxic biomolecules from cyanobacteria (chapter 4), and production dynamics and environmental fate processes of natural products (chapter 5). At the beginning of each chapter, you find a brief overview followed by the individual studies. In chapter 6, I highlight new avenues of my current and future research on the environmental chemistry of cyanobacterial toxins. Chapter 1 and chapter 6 are original parts of this habitation thesis that have not previously been published.