Abstract
In this article, the mechanisms of thermoinactivation of glucose isomerase (GI) from Streptomyces rubiginosus (in soluble and immobilized forms) were investigated, particularly the contributions of thiol oxidation of the enzyme’s cysteine residue and a “Maillard-like” reaction between the enzyme and sugars in high fructose corn syrup (HFCS). Soluble GI (SGI) was successfully immobilized on silica gel (13.5 μm particle size), with an activity yield between 20 and 40%. The immobilized GI (IGI) has high enzyme retention on the support during the glucose isomerization process. In batch reactors, SGI (half-life =145 h) was more stable than IGI (half-life=27 h) at 60°C in HFCS, whereas at 80°C, IGI (half-life=12 h) was more stable than SGI (half-life=5.2 h). IGI was subject to thiol oxidation at 60°C, which contributed to the enzyme’s deactivation. IGI was subject to thiol oxidation at 80°C, but this did not contribute to the deactivation of the enzyme. SGI did not undergo thiol oxidation at 60°C, but at 80°C SGI underwent severe precipitation and thiol oxidation, which caused the enzyme to deactivate. Experimental results show that immobilization suppresses the destablizing effect of thiol oxidation on GI. A “Maillard-like” reaction between SGI and the sugars also caused SGI thermoinactivation at 60, 70, and 80°C, but had minimal effect on IGI. At 60 and 80°C, IGI had higher thermostability in continuous reactors than in batch reactors, possibily because of reduced contact with deleterious compounds in HFCS.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Volkin, D. B. and Klibanov, A. M. (1989), Biotechnol. Bioeng. 33, 1104–1111.
Quax, W. J. (1993), Trends Food Sci. Technol. 4, 31–34.
Visuri, K., Pastinen, O., Wu, X., Makinen, K., and Leisola, M. (1999), Biotechnol. Bioeng. 64(3), 377–380.
Bailey, J. E. and Ollis, D. F. (1986), Biochemical Engineering Fundamentals. 2nd ed. McGraw-Hill, New York.
Guisan, J. M., Fernandez-Lafuente, R., Rodriguez, V., Bastida, A., Blanco, R. M., and Alvaro, G. (1992), In: Proceedings of the International Symposium on Enzyme Stability. Maastricht, The Netherlands, November 22–25.
Mozhaev, V. V. (1992), In: Proceedings of the International Symposium on Enzyme Stability, Maastricht, The Netherlands, November 22–25.
Weetall, H. H. and Filbert, A. M. (1974) In: Methods in Enzymology. Jakoby, W. B. and Wilchek, M. (eds.), Academic Press, New York, 59–72.
Wiseman, A. (1995), Handbook of Enzyme Biotechnology. 3rd ed. Ellis Horwood, London.
Ninfa, A. J. and Ballou, B. P. (1998), Fundamental Laboratory Approaches for Biochemistry and Biotechnology. Fitzgerald Science Press, Bethesda, MD.
Sadana, A. (1992), In: Thermostability of Enzymes. Gupta, M. N. (ed.), Springer-Verlag, Berlin, pp. 84–93.
Gibbs, P. R., Uehara, C. S., Neunert, U., and Bommarius, A. S. (2005), Biotechnol. Prog. 21, 762–774.
Palazzi, E. and Converti, A. (2001), Enzyme Microb. Technol. 28, 246–252.
Weiss, N. A. (1999), Elementary Statistics. 4th ed. Addison Wesley Longman, Inc., USA.
Lim, L. H. (2006), PhD Thesis, Department of Chemical Engineering and Applied Chemistry, University of Toronto.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2007 Humana Press Inc.
About this chapter
Cite this chapter
Lim, L.H., Saville, B.A. (2007). Thermoinactivation Mechanism of Glucose Isomerase. In: Mielenz, J.R., Klasson, K.T., Adney, W.S., McMillan, J.D. (eds) Applied Biochemistry and Biotecnology. ABAB Symposium. Humana Press. https://doi.org/10.1007/978-1-60327-181-3_11
Download citation
DOI: https://doi.org/10.1007/978-1-60327-181-3_11
Publisher Name: Humana Press
Print ISBN: 978-1-60327-180-6
Online ISBN: 978-1-60327-181-3
eBook Packages: Chemistry and Materials ScienceChemistry and Material Science (R0)