Fig. 7

Addition of different cellulase inducers and media supplements to the culture of T. reesei Rut-C30. T. reesei Rut-C30 was grown on 5 g L⁻¹ glucose and 30 g L⁻¹ α-cellulose. Oxygen transfer rate (OTR), cumulative oxygen transfer (OT), filter paper activity and protein content in the culture supernatant of a culture without and with addition of 0.24 g L⁻¹ (0.7 mm) cellobiose or sophorose after 28 h of cultivation (a, c, e) and a culture medium supplemented with 0.3 g L⁻¹ urea, 0.1 % (v/v) tween 80, 2 g L⁻¹ peptone or the mix of all three compounds (b, d, f). The filter paper activity and the protein content in the culture supernatant were measured after 168 h. The OTR was measured in duplicates. As the maximum mean error was as low as 0.5 mmol L⁻¹ h⁻¹, average values are shown. For clarity only every fourth (OTR) and every eighth (OT) measuring point over time is represented by a symbol in (a–d), respectively. In e and f an asterisk marks a significant increase in filter paper activity compared to a culture without additions with significance level of 95 %, two asterisks correspond to a level of 99 %. Error bars represent standard deviation of technical triplicates. Culture conditions: modified Pakula medium, 250 mL flask, filling volume 20 mL, shaking frequency 350 rpm, shaking diameter 50 mm, inoculum 10⁶ spores mL⁻¹, and 30 °C