Results and Discussion
For enzyme production from T. reesei RUT-C30, pretreated corn stover (CF) was used as an inducer. To increase the ratio of cellulose to hemicellulose fraction, corn stover was first pretreated with wet oxidation and then alkali method (composition can be found in Table 3.1). To maintain a high carbon level throughout the fermentation, saccharified corn mash was fed to the reactor gradually such that 0.5-1.5 g/l of glucose could be found unassimilated through the 144 h fermentation. As can be observed in Fig. 3.1, after 6 days of fermentation, the glucose and oxygen assimilation were reduced as the fungus entered into the stationary phase. As a result of 7-day fermentation, a total of 14 mg/mL protein and 4.49 FPU/mL cellulase activities was obtained.
Xylose has previously been shown to induce p-glucosidase production in Aspergillus saccharolyticus, data not shown.
Fig. 3.1 Dissolved oxygen saturation (%), temperature (°C), pH, glucose concentration (gL 1), and protein content (mg mL-1) during fermentation of T. reesei RUT-C30