Abstract
The release of volatile organic compounds (VOCs) by eukaryotic microbes is of interest for several fields, comprising food, environmental, biotechnological and medical applications. In addition, it represents an intriguingly opportunity to conceive and to confirm new hypotheses in fundamental biology and in breeding sciences. For example, VOCs studies in an -omics perspective are generally defined as volatome, indicating with this terms the organic volatile subset of metabolome. The various techniques for VOC anal ysis generally aim tocombine either sample throughput or analytical insight. From this point of view, Proton Transfer Reaction Time of Flight Mass Spectrometry (PTR-ToF-MS) represents a valid compromise, with the advantages of on-line process monitoring and non-invasive analysis. In order to maximize the advantages of on-line bioprocess monitoring, we coupled PTR-ToF-MS with an auto-sampler, adding a tailored data analysis tools. Wedemonstrated the applicability of our comprehensive methodology (automatic sampling, PTR-ToF-MS analysis and tailored data handling and analysis) the study Saccharomyces cerevisiae volatile organic compounds released during alcoholic fermentations. In particular, considering bread-making bioprocess, we use this approach i) to differentiate bakery yeast starter cultures in reason of their release of VOCs and to analyze the effect on VOCs productivity as a function of ii) different bakery yeast starter cultures/flour combinations, ii) the interaction between S. cerevisiae and Lactobacillus sanfranciscensis as model microorganisms in the sourdough environment, iv) different commercial aromatic yeast starter cultures for bakery.