represent the results of three separates bottles. The exponential
growth phase stopped between 36 and 48 h of
fermentation followed with a slow decrease in protein concentration
from particulate fragment. The large standard deviation
at 36 h may have been caused by different lag times in
each of the different bottles prior to the start of growth. The
culture pH continued to drop after the end of the exponential
phase, showing that bacteria were still active until pH reached
5.83 (±0.05), the minimum reached by every sample after 60 h
and beyond of fermentation. C. thermocellum cells were not the
only contributors to the protein content measured in the
particulate fragment, since the protein concentration
measured in the pellets of the uninoculated media was 16.6
(±0.3) g m3