The behavior against temperature and thermal stability of enzymes is a topic of importance
for industrial biocatalysis. This study focuses on the kinetics and thermodynamics of the thermal
inactivation of Lipase PS from B. cepacia and Palatase from R. miehei. Thermal inactivation was
investigated using eight inactivation models at a temperature range of 40–70 ◦C. Kinetic modeling
showed that the first-order model and Weibull distribution were the best equations to describe
the residual activity of Lipase PS and Palatase, respectively. The results obtained from the kinetic
parameters, decimal reduction time (D and tR), and temperature required (z and z’) indicated a higher
thermal stability of Lipase PS compared to Palatase. The activation energy values (Ea) also indicated
that higher energy was required to denature bacterial (34.8 kJ mol−1
) than fungal (23.3 kJ mol−1
)
lipase. The thermodynamic inactivation parameters, Gibbs free energy (∆G#
), entropy (∆S
#
), and
enthalpy (∆H#
) were also determined. The results showed a ∆G#
for Palatase (86.0–92.1 kJ mol−1
)
lower than for Lipase PS (98.6–104.9 kJ mol−1
), and a negative entropic and positive enthalpic
contribution for both lipases. A comparative molecular dynamics simulation and structural analysis
at 40 ◦C and 70 ◦C were also performed.
