The analysis was performed as recently described [24] with the following modifications for P. pastoris. For immediate chilling of metabolic activities P. pastoris samples (4 × 2 mL) were immediately mixed with 200 μL inhibition solution (95:5 v/v ethanol/phenol, pre-cooled at -20°C). After centrifugation (2 min, 13000 rpm, 4°C) the supernatant was removed and the pellet was dispensed in 100 μl of RNA Later (Ambion) and stored at -70°C until analysis. Total RNA extraction was performed with the RNeasy Mini Kit and mechanical cell disruption according to the manufacturers instructions (Qiagen).