Fig. 6

Decreased effect of ammonium sulfate supplementation with longer corn steep liquor (CSL) storage times on Ogataea polymorpha in a µTOM device. (A-B) Oxygen transfer rate (OTR) of O. polymorpha RB11 pC10-FMD (P_FMD-GFP) on CSL medium supplemented with different concentrations of ammonium sulfate. The CSL batch 1 used in (A) was stored at 4 °C for 16.5 months. The OTR data in (A) are identical to those displayed in Fig. 4A. The data shown in (B) were generated using the same CSL batch 1 employed in (A), only at a later time, resulting in a storage time of the CSL batch 1 of 23 months. Data points shown are mean values measured from 4–6 individual wells. Shadows indicating the respective standard deviation are barely visible, caused by the low standard deviations < 0.5. Experimental parameters: round deep-well 96-well microtiter plate (MTP), CSL 1 concentration \(\:{c}_{CSL,1}\) = 2.5 g dry substance/L, glucose concentration \(\:{c}_{glucose}\) = 5 g/L, ammonium sulfate concentration \(\:{c}_{(N{H}_{4}{)}_{2}S{O}_{4}}\) = 0–0.7 g/L, MES buffer concentration \(\:{c}_{MES}\) = 0.1 M, initial pH = 6.0, culture volume V_L = 200 µL/well, shaking frequency n = 350 rpm, shaking diameter d₀ = 50 mm, humidity = 80%, temperature T = 37 °C and initial OD₆₀₀ = 0.1