Economic growth and the growing world energy demand highlight the importance of using
renewable energy resources, therefore, agro-industrial residues emerge as promising
alternatives for raw materials for various bioproducts. Among the various enzymes applied in
biocatalysis, lipases gained great prominence in biotechnology and in the industrial market for
the production of biodiesel. Due to the thematic relevance, the present dissertation aims to
develop a one-dimensional mathematical model, capable of simulating the heat transfer in the
lipase production process, by solid-state fermentation, in a tray bioreactor. For this, individual
equilibrium equations were written for the solid and gaseous phases and the constitutive
relationships that explain the effect of environmental conditions on the performance of the
bioprocess were simulated using Matlab R2022b (MathWorks Inc., Natick, Massachusetts,
United States). The parameters used in the simulation were obtained through previous research,
conducted by students and graduate students in the laboratory. In the simulation, the humidity
and air inflow were considered constant throughout the fermentation process. The proposed
model was able to predict the temperature profiles and the kinetics of lipase production,
obtained based on the release of CO 2 molecules by the respiratory metabolism of the
microorganism, throughout the cultivation process and in any position of the bed. The
simulation data showed a negative influence on the increase in the thickness of the substrate
load, inhibiting the growth of lipases with the expansion of the variation of the temperature
profiles throughout the fermentation. This condition was caused by the accumulation of
metabolic heat generated in the culture medium of the trays in the bioreactor. In the simulation
results, it was observed that the time employed of 7 days and loads of 1 cm of substrate, proved
to be the most efficient combination for enzymatic biosynthesis.
|
