Spotting assay on iron deficient media. Serial 1:10 dilutions of P. pastoris CBS7435 wild type, AFT1-OE and Δaft1 cell suspensions were spotted on YP plates containing either 2% glucose or 1% methanol as carbon source and on YNB agar plates containing 2% glucose as carbon source. Iron-deficient conditions were generated by addition of the iron chelator BPS (2000M). Plates were incubated at 28°C for 70h. While addition of BPS resulted in generally delayed growth on both substrates, no difference between the strains was seen.