Fig. 4
Organic acid production in shake flask cultivations with different initial malic and succinic acid concentrations. Malic acid was added at concentrations of 2–50 g/L (left column of figure) and combinations of malic and succinic acid were added at concentrations ranging from 1 + 1 g/L to 25 + 25 g/L (right column of figure). Cultures were incubated at 32 °C and 120 rpm using 90 g/L CaCO3. In the pre-culture, A. oryzae was grown using 45 g/L acetic acid as carbon source. M malic acid, S succinic acid. Datapoints represent means ± standard deviation, n = 3