Temperature optimization for reactor operation with chitin-immobilized lactase under modulated inactivation

Area of Science:

• Biotechnology
• Enzyme kinetics
• Biochemical engineering

Background:

• Lactase enzyme is crucial for lactose hydrolysis.
• Enzyme stability and activity are temperature-dependent.
• Immobilized enzymes offer advantages in industrial applications.

Purpose of the Study:

• To determine temperature effects on kinetic and inactivation parameters of chitin-immobilized lactase (CIL) from Kluyveromyces marxianus.
• To model enzyme inactivation mechanisms and the influence of galactose and lactose.
• To optimize the operating temperature for a sequential batch reactor using CIL.

Main Methods:

• Kinetic and inactivation parameters were measured across a range of temperatures.
• Enzyme inactivation was modeled using a two-stage series mechanism.
• Temperature-explicit functions were developed for optimization.

Main Results:

• Maximum reaction rate, Michaelis constant, inhibition constant, and inactivation rates increased with temperature.
• Galactose positively modulated inactivation, while lactose negatively modulated it.
• Temperature optimization functions were integrated into a cost-based objective function.

Conclusions:

• Temperature-dependent kinetic and inactivation parameters are essential for optimizing CIL reactor operation.
• Galactose and lactose modulate CIL inactivation differently with temperature.
• Developed software enables sensitivity analysis for CIL operational criteria.