Fig. 6.

Cultivation of U. maydis AB33P5ΔR/AtPgaX on polygalacturonic acid with varying initial glucose concentrations. The strain was grown on glucose (4, 12 and 20 g/L) and polygalacturonic acid (20 g/L) as carbon sources. a Mean value of biological duplicates of oxygen transfer rate. b Mean value of biological duplicates of respiratory quotient. The dotted horizontal line represents RQ = 1. c Predicted residual polygalacturonic acid concentration in the medium (PolyGalA_calc) according to Eq. (6). The RQ drops below 1 after 29 h, indicating depletion of galacturonic acid liberation. Thus, the line for PolyGalA_calc in Fig. 6c is dotted from that time point on. The mean values of biological duplicates are shown for better clarity. Culture conditions: modified Verduyn medium, 0.1 M MOPS and 0.1 M MES, initial pH 6.0, 250 mL flask, filling volume 15 mL, shaking frequency 350 rpm, shaking diameter 50 mm, initial OD₆₀₀ = 0.6, temperature 30 °C