Malt extract

The morphology of strain CBS 554.65 was inspected on minimal medium [22 ] and malt extract agar (30 g/L malt extract (AppliChem, Darmstadt, Germany) and 5 g/L peptone from casein (Merck KGaA, Darmstadt, Germany)). The strain was 4-point inoculated and incubated at 30 °C for one week.

For sterol analysis, wt and tunable A. fumigatus strains were grown in Aspergillus minimal medium (AMM) containing 20 mM ammonium tartrate as the nitrogen source and 1% glucose as the carbon source [47 (link)]. Cultures were inoculated with a final concentration of 1.0 × 10⁶ spores/mL of each strain and incubated for 20 h at 37 °C, 200 rpm. Mycelia were harvested through filtration, shock-frozen and freeze-dried.
For S. cerevisiae, the DSMZ 186 universal medium for yeast was used for cultivation. The medium contained 3.0 g of yeast extract, 10.0 g of glucose and 15.0 g of agar from Sigma Aldrich (Steinheim, Germany); 3.0 g of malt extract from AppliChem GmbH (Darmstadt, Germany); and 5.0 g of peptone from soyabean from Oxoid (Basingstoke, Hampshire, UK). All components were dissolved in 1000 mL of deionized water and autoclaved for 10 min at 121 °C before use. Cell cultures were maintained at 28 °C and split once a week to keep the yeast in a log phase [28 (link),48 (link)].
Cell matrix for method development and validation was obtained by incubating 2 mL of 5.0 × 10⁵ CFU/mL in DSMZ 186 medium in 24-well plates at 28 °C for 48 ± 2 h.