The high value 1.56 for linear coefficient of substrate concentration
(Eq. (4)) illustrates the significant, positive effect of variable
on the cellulase activity. Linear coefficient indicates the increase in
cellulase activity more with increase in the substrate than enzyme
concentration, indicated less enzyme loading rate required. The
negative linear coefficient of pH and temperature demonstrates an
increase in cellulase activity, with rises of these variables initially
in the ranged assay. The negative quadratic coefficient for all the
variables indicates the existence of maximum activity to a point;
beyond that the entire variable had an inhibitory effect on cellulase
activity. In order to determine the optimal levels of each variables
for maximum cellulase activity, counters plots were constructed
by ploting the response. The response surface was selected based
on the interactive effect of two independent variables with another
variable being at fixed level.