Enzyme Production of A. oryzae in Solid-State Fermentation
Time profiles for enzyme production by A. oryzae in the
rotating drum bioreactor using the three control systems
were compared (Fig. 8). Based on the results, FLC-No2
was the most effective control system for enhanced
production of both protease and amylase. Enzyme activity
of A. oryzae in the solid-state fermentation process (Table 3)
showed that the fuzzy logic control system No.2 yielded
the highest enzyme activity, which was 1.1-folds higher
than the activity obtained by the conventional control and
1.4-folds higher than the activity obtained by the fuzzy
logic control No.1.
Temperature and moisture content are two important
factors for optimal growth and enzyme production of A.
oryzae in solid-state fermentation. In this study, we proved
that a fuzzy-based control strategy can control these
factors in a rotating drum bioreactor effectively. We also
showed that the designed fuzzy control system enhanced
the production of biomass and the enzyme production of A.
oryzae. Thus, the fuzzy logic control is regarded as a
promising automatic control system that can be applied to
the control of culture parameters in a solid-state fermentation
process. The FLC model presented in this study may also
be used for optimization of other industrial solid-state
fermentation processes.