Fig. 3

Process kinetics from uncontrolled and pH controlled cultivations in stirred tanks (1.5 L) and culture appearance at harvest time. All cultures were prepared with O. nidiformis cultivated in G13.5/C7 medium at 23 °C, aeration 0.3 vvm (27 sL h⁻¹) and dissolved oxygen (DO) was maintained at 5% by increasing the stirring speed. a No pH control b pH 4.5 c pH 6.0 and d pH6.5. All curves illustrating the course of different process parameters are colored according to the color of the axis labels. Illudin M titers were derived from cell free culture supernatant. The concentration of wet biomass at harvest was as follows for a 45.83 g L⁻¹; b 40.81 g L⁻¹; c 23.59 g L⁻¹ and c 18.07 g L⁻¹