Fig. 4
From: Development of an itaconic acid production process with Ustilaginaceae on alternative feedstocks
Determination of a correlation between the maximum obtained oxygen transfer rate (OTRN,max) and ammonium ion (NH4+) concentration using U. cynodontis ITA Max pH. (A) Course of the oxygen transfer rates with addition of specific NH4+ concentrations in modified Verduyn medium. (B) Correlation between OTRN,max and NH4+ concentration. Cultivations were performed in a 96 round deep-well MTP, filled with 300 µL modified Verduyn medium with 50 g/L sucrose and 0.135-0.675 g/L NH4+ (0.4-2.0 g/L NH4Cl) at 30 °C, 350 rpm shaking frequency and a shaking diameter of 50 mm. 30 mM MES were added to the cultivations. The initial pH was set to 6.5 for all cultivations. Graphs show the mean of three replicates, with standard deviation as shaded area. Due to high reproducibility of the measurements, the standard deviation might not be visible for every data point. For clarity, only every fourth data point is shown