For the production of crude extracts, a seed culture of the W. anomalus and W. saturnus var. mrakii strains was incubated at 20 °C for 24 h with shaking at 150 rpm in YPD medium. Flasks (500-mL volume) containing 100 mL of YPD buffered at pH 4.6, with 15% glycerol, were inoculated with 1 mL of the seed culture and incubated at 20 °C for 72 h with shaking (150 rpm). After this period, the cells were removed by centrifugation (5000× g, 10 min, 4 °C); the supernatant was filtered through 0.45 µm pore size membranes (Merck Millipore, Darmstadt, Germany) and concentrated (50-fold) through an Amicon Ultra-15 (10-kDa cutoff) filter unit (Merck Millipore) by centrifugation at 4000× g, 4 °C. Accordingly, a concentrated extract of YPD medium used for KT production was prepared. The concentrated crude extracts were stored at 4 °C until use.