<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Thermal inactivation of a commercial <italic>β</italic>-galactosidase from <italic>Aspergillus oryzae</italic> in a 300 g/L lactose solution was studied in the temperature range of 65–75 °C. Lactose exhibited a stabilisation effect when similar inactivation rates as those in lactose solution were observed in a lactose-free solution at temperatures lower by 5°C. Inactivation process in the lactose solution was biphasic. A kinetic model based on the Lumry-Eyring mechanism was proposed and successfully verified. Estimated activation energy values were very different. Rather high activation energy values of the forward reactions were responsible for both the significant change of rate constants and the rate-controlling reaction with temperature. For these two reasons, an increase of the operational lifetime of the enzyme from 7 days at 60 °C to 580 days at 55 °C was predicted.</p></abstract>

Thermal inactivation of a commercial β-galactosidase from Aspergillus oryzae in a 300 g/L lactose solution was studied in the temperature range of 65–75 °C. Lactose exhibited a stabilisation effect when similar inactivation rates as those in lactose solution were observed in a lactose-free solution at temperatures lower by 5°C. Inactivation process in the lactose solution was biphasic. A kinetic model based on the Lumry-Eyring mechanism was proposed and successfully verified. Estimated activation energy values were very different. Rather high activation energy values of the forward reactions were responsible for both the significant change of rate constants and the rate-controlling reaction with temperature. For these two reasons, an increase of the operational lifetime of the enzyme from 7 days at 60 °C to 580 days at 55 °C was predicted.

Thermal inactivation kinetics of <italic>Aspergillus oryzae β</italic>-galactosidase in concentrated lactose solution

Department of Chemical and Biochemical Engineering, Institute of Chemical and Environmental Engineering, Faculty of Chemical and Food Technology

Acta Chimica Slovaca

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Thermal inactivation kinetics of -galactosidase in concentrated lactose solution

Thermal inactivation of a commercial β-galactosidase from Aspergillus oryzae in a 300 g/L lactose solution was studied in the temperature range of 65–75 °C....

Thermal inactivation kinetics of Aspergillus oryzae β-galactosidase in concentrated lactose solution

Publié en ligne: 19 déc. 2018

Pages: 170 - 174

DOI: https://doi.org/10.2478/acs-2018-0024

Mots clés
-galactosidase, thermal inactivation, kinetics, Lumry-Eyring mechanism, multitemperature modelling

© 2018 Viera Illeová et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Thermal inactivation kinetics of Aspergillus oryzae β-galactosidase in concentrated lactose solution

Publié en ligne: 19 déc. 2018

Pages: 170 - 174

DOI: https://doi.org/10.2478/acs-2018-0024

Mots clés-galactosidase, thermal inactivation, kinetics, Lumry-Eyring mechanism, multitemperature modelling

© 2018 Viera Illeová et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Mots clés
-galactosidase, thermal inactivation, kinetics, Lumry-Eyring mechanism, multitemperature modelling