Kinetic and thermodynamic aspects of the process of thermal inactivition of kluyveromyces marxianus inulinase

Abstract

Background: Inulinase is widely found in microorganisms and higher plants. It catalyzes the reaction of the hydrolysis of inulin, which is present in the tubers and roots of many plants, to fructose and a small amount of glucose.

Inulin is one of several plant-based polysaccharides that contain glucose or fructose. It is used as a substrate in industrial fermentation processes and in the food industry due to its relatively cheap and abundant source for the microbiological production of high fructose juices, ethanol, acetone and butanol. Inulin-derived oligosaccharides are also used in the medical and food sectors. Inulinase which produced from the yeast K. marxianus at levels close to commercial use. This indicates that inulinase can be used in the production of fructose and fructose syrups. So our main object is to study the effect of different temperatures on the conformation of the Kluyveromyces marxianus inulinase macromolecule, to provide optimal conditions for aniline hydrolysis by inulinase.

Materials and method: Method of isolation and purification of the inulinase enzyme from Kluyveromyces marxianus, as well as the determination of the protein content and enzyme activity as mentioned in the context of the research. Experiments were carried out to study the thermal stability of enzyme. For this, an enzyme solution at a concentration of 5•10-5 mol / l was incubated in a time interval of 10-60 min at different temperatures, followed by determination of the catalytic activity.

It is known that different types of bonds and interactions participate in the formation of the molecular structure of enzymes, which are covalent bonds, hydrogen bonds, salt bridges, hydrophobic interactions, so our main goal is to study the effect of different temperatures on the formation of the enzyme molecule in order to provide optimal conditions for aniline hydrolysis. by enzyme.

Results: of this study revealed that the residual activity of the enzyme after 60 minutes of incubation at 50 °C was 10% of the initial activity at 60 °C 7%. As for the Rate Constants of thermal inactivation of Inulinase at 70 °C were 3.45.

Conclusions: Results of this study were important and useful in determining parameters of inulinase enzyme. Based on the shape of the curves of the dependence of the catalytic activity of Kluyveromyces marxianus inulinase on the time of thermal inactivation in the temperature range of 20-80 ° C.