The sensation of smell, driven by volatile organic compounds, is fundamental to all life forms, yet research into microbial volatiles remains limited. Saccharomyces cerevisiae, a key player in biotechnology and ethanol production, has an underexplored gas phase during fermentation. This work seeks to enhance understanding of the yeast volatilome by addressing unwanted volatiles, maximizing valuable ones, and developing new analytical methods. Notably, carbon dioxide, often overlooked in climate discussions, was converted to formic acid using a Ru-catalyst in a high-pressure setup. Additionally, biotechnological processes face high purification costs, which could be alleviated by increasing volatile metabolite yields. For instance, acetaldehyde, primarily derived from petrochemical sources, was produced from glucose using S. cerevisiae with deleted alcohol dehydrogenase activity. This low-boiling compound is stripped from reactors and must be captured from off-gas. A novel method, SESI-Orbitrap MS, was established to analyze the heat-sensitive compound allicin from garlic, measured in various contexts including human breath. Differences among Allium species were also explored. Furthermore, the complete yeast volatilome was analyzed online from fermentation off-gas, revealing over 200 compounds with distinct intensity profiles and two metabolic shifts, while acetaldehyde was detected significantly earlier than with standard tech
