The anaerobic batch fermentations were conducted in 250 mL
Scott Duran bottles with 150 mL of working volume. For all
fermentation experiments conducted in this study, the fermentation
medium was raw POME without any nutrient supplementation. The
initial medium pH was adjusted to 5.8 by 1 M NaOH or 1 M HCl.
POME was sterilized by autoclaving at 121 1C for 15 min; prior to the
inoculation, the medium was sparged with oxygen-free nitrogen to ensure anaerobic conditions. The inoculum of C. saccharoperbutylacetonicum
N1-4 (ATCC13564) was grown in TYA medium in a
250 mL Scott Duran bottle in anaerobic condition at 30 1C for 20 h.
This culture was used as inoculum, and the size of inoculum was 10%
(v/v) and then incubated at 30 1C.