Fig. 5.

Time course of acetoin production from APC by strain IPE5-4-UD-4 in a fermenter. The cultivation was conducted with 3 L medium containing 5% (w/v) APC at 50 °C for 72 h. Cellulase at a final dosage of 15 FPU/g substrate was diluted, filter sterilized, and added along with seed-culture. The agitation speed was maintained at 200 rpm for the first 24 h, and then increased to 400 rpm with an airflow rate of 0.6 vvm. The pH was controlled at 6.5 by automatic adding 5 M HCl and 5 M NaOH