In the present study, the cumulative hydrogen and methane
production data obtained after dark fermentation followed by
biomethanation of raw and pretreated sugarcane top in batch test
were used to fit the modified Gompertz model using MATLAB
(Curve fitting tool box ver. 1.1.7) software. These are shown in
Fig. 4a and 4b. The kinetic parameters i.e. lag time (k), maximum
hydrogen and methane production rate (Rm) and hydrogen and
methane production potential (P) were estimated and these are
summarized in the Table 2. The correlation coefficient (R2
) value
in all the cases ranged over 0.99, indicating a strong correlation
between the experimental data and the fit i.e. the modified Gompertz
equation adequately describe the formation of hydrogen
and methane. Table 2 also show the amount of product formation
increased after pretreatment of sugarcane top. In addition, the lag
times (k) of hydrogen and methane production were decreased
with pretreated sugarcane top. This indicates that pretreatment
of biomass could increase the substrate utilization and decrease
the lag time for hydrogen and methane production using mixed
microflora.