Abstract:
:In view of a possible application of the alpha-amylase from Bacillus licheniformis as a time-temperature integrator for evaluation of heat processes,(11) thermal inactivation kinetics of the dissolved and covalently immobilized enzyme were studied in the temperature range 90-108 degrees C. The D-values (95 degrees C) for inactivation of alpha-amylase, dissolved in tris-HCl buffer, ranged from 6 to 157 min, depending on pH, ionic strength, and Ca(2+) and enzyme concentration. The z-value fluctuated between 6.2 and 7.6 degrees C. On immobilization of the alpha-amylase by covalent coupling with glutaraldehyde to porous glass beads, the thermoinactivation kinetics became biphasic under certain circumstances. For immobilized enzyme, the D-values (95 degrees C) ranged between 17 and 620 min, depending largely on certain environmental conditions. The z-value fluctuated between 8.1 and 12.9 degrees C. In each case of biphasic inactivation, the z-value of the stable fraction (with the higher D-values) was lower than the z-value of the labile fraction.
journal_name
Biotechnol Bioengjournal_title
Biotechnology and bioengineeringauthors
De Cordt S,Vanhoof K,Hu J,Maesmans G,Hendrickx M,Tobback Pdoi
10.1002/bit.260400309subject
Has Abstractpub_date
1992-07-01 00:00:00pages
396-402issue
3eissn
0006-3592issn
1097-0290journal_volume
40pub_type
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