Fractionation of enzyme B by ultrafiltration indicated
that most of the response occurred with filtrates
containing substances of molecular mass > 100 kDa (Table 3). As the nominal molecular mass cut-off decreased,
the amount of stimulation of gas production
decreased. Autoclaving destroyed the stimulatory activity
of all of the fractions (not shown). The CMCase
activity was mostly > 100 kDa, whereas most of the
xylanase was < 100 kDa, suggesting a stronger relation
between gas production and CMCase rather than xylanase
activity.