Determining Antimicrobial Activity of S. albidoflavus

The modified microplate dilution method described by the Clinical and Laboratory Standards Institute (CLSI) was used to determine the minimum inhibitory concentration (MIC) of the lyophilized supernatant of S. albidoflavus Q (23 (link), 66 ). Briefly, stock solutions were prepared with the lyophilized supernatant in RPMI 1640 medium (Sigma-Aldrich). The yeasts were then grown in YPD liquid yeast medium at 37°C for 24 h. The pre-inoculum OD₆₂₀ = 0.6 was established before performing serial 1:1,000 dilutions to obtain the inoculum. Solutions of the supernatant or fluconazole (the inhibition control) were placed in microplates and incubated at 37°C for 24 h. The absorbance was read in a Thermo Scientific Multiskan FC microplate spectrophotometer at 620 nm (23 (link)).