FFoQSI 3.3.4 Mould & Metabolite Profiling

Mould identification at the species level in environmental samples is a major challenge. Baker’s yeast, Saccharomyces cerevisiae, is the microorganism of choice for the common fermentation process in bread production. Growth conditions, including humidity and temperature, are optimized in bakeries to allow for ideal proliferation. However, these environmental conditions also enable the growth of microorganisms such as various mould species that can contaminate the final product directly or indirectly via released mycotoxins or other secondary metabolites of fungi. Therefore, these microorganisms pose a marked health risk not only to the end consumer but also to involved bakery workers. Irrespective of the health risks, contamination by mould also negatively affects the shelf-life of bakery goods. If mould preventive measures in bakeries fail, it will be important to identify the contaminating species in order to develop optimized strategies. However, this is still a critical challenge, and better methods are urgently needed. We have previously reported on the identification of moulds using DNA-barcoding in combination with mycotoxin analysis and light microscopy. Based on the combination of eight primer pairs, it is possible to identify mould at the species level within a single PCR run and thereby adequate throughput. However, in order to optimize validity, effectiveness and throughput of the approach, further steps need to be taken. These include: • Establishment of further pure mould cultures from various commercial collections. • An optimization of DNA extraction methods, as the DNA quality is crucial for PCR performance. • Validation of novel primer combinations either self-designed or evidenced from literature. • Combination with complimentary methods including microscopy, NGS technology and LC-MS- based targeted and non-targeted metabolomics-based approaches to study the presence of the whole set of secondary metabolites including novel compounds and mycotoxins.