TITLE:
Thermodynamic Characterization of Saccharomyces cerevisiae Catalyzed Fermentation of Cane Sugar
AUTHORS:
Egharevba Felix, Ogbebor Clara, Akpoveta Oshevwiyo Vincent
KEYWORDS:
Fermentation; Substrate Concentration; Kinetics; Cane sugar; Thermodynamic Parameters
JOURNAL NAME:
Open Journal of Physical Chemistry,
Vol.4 No.1,
February
25,
2014
ABSTRACT: The rate of cane
sugar fermentation with Saccharomyces cerevisiae was studied at temperatures between 30°C and 42°C in order to characterize
the process using thermodynamic parameters such as enthalpy (ΔH*), activation energy (ΔE*),
entropy (ΔS*), Gibbs free energy (ΔG*) and equilibrium
constant (K). The parameters were evaluated on the basis of a consideration of
Arrhenius, Eyring and Van’t Hoff’s equations. The results obtained are ΔH*,
91.85 KJ·mol-1; ΔE*, 91.85 KJ·mol-1, ΔS*, 2763 J·mol-1K-1; ΔG*,
-762.09 KJ·mol-1, and equilibrium constant, K, 1.34 dm3·mol-1. These
values were subsequently used to obtain by calculation the rate constant of the
fermentation k, 1.43 × 1011 min-1, Arrhenius constant A
(pre-exponential or frequency factor), 4.79 × 1026 min-1, orientation parameter, P, 4.48 × 1015 and the collision frequency Z, 1.07 × 1011 min-1.
Finally the fermentation efficiency calculated on the basis of a complete
combustion of glucose is 377.8%. The results showed that though the
fermentation process is kinetically controlled, it is suggested that the
positive impact of the feasible thermodynamics is limited by other process
variables.