Influence of immobilization on the thermal inactivation of yeast invertase

Vrábel, Peter; Polakovič, Milan; Godó, Š.; Báleš, V.; Dočolomanský, Peter; Gemeiner, Peter

doi:10.1016/s0141-0229(96)00266-9

Cited by 25 publications

(8 citation statements)

References 18 publications

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“…In order to verify the first-order model of PME inactivation, multitemperature evaluation was applied (Vrábel, Polakovič, Godó et al, 1997;Vrábel, Polakovič, Š tefuca et al, 1997) where a model is forced to fit all measured Fig. 3.…”

Section: Resultsmentioning

confidence: 99%

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Thermal inactivation of exogenous pectin methylesterase in apple and cloudberry juices

Wilińska¹,

Rodrigues²,

Bryjak³

et al. 2008

Journal of Food Engineering

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Section: Resultsmentioning

confidence: 99%

“…When the model was validated by the isothermal evaluation, it was further tested by the multi-temperature evaluation (Vrábel, Polakovič, Godó et al, 1997;Vrábel, Polakovič, Š tefuca et al, 1997). Eq.…”

Section: Kinetic Analysismentioning

confidence: 99%

Thermal inactivation of exogenous pectin methylesterase in apple and cloudberry juices

Wilińska¹,

Rodrigues²,

Bryjak³

et al. 2008

Journal of Food Engineering

Self Cite

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“…Determination of enzyme deactivation parameters through non-isothermal measurements has been attempted with lipase (6), an esterase-like lipase (Candida antarctica lipase B, CALB) (2), glucoamylase from Aspergillus niger (34), jack bean urease (35), and yeast invertase (28,36). The studies with invertase were the first to show that non-isothermal experiments yield more accurate parameters for deactivation than isothermal ones.…”

Section: Introductionmentioning

confidence: 99%

Accelerated Biocatalyst Stability Testing for Process Optimization

Gibbs

Uehara²,

Neunert

et al. 2008

Biotechnol Progress

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The deactivation of protein biocatalysts even at relatively low temperatures is one of the principal drawbacks to their use. To aid in the development of novel biocatalysts, we have derived an equation for both time- and temperature-dependent activity of the biocatalyst based on known concepts such as transition state theory and the Lumry-Eyring model. We then derived an analytical solution for the total turnover number (ttn), under isothermal operation, as a function of the catalytic constant kcat, the unfolding equilibrium constant K, and the intrinsic first-order deactivation rate constant(s) k(d,i). Employing an immobilized glucose isomerase biocatalyst in a CSTR and utilizing a linear temperature ramp beyond the Tm of the enzyme, we demonstrate an accelerated method for extracting the thermodynamic and kinetic constants describing the biocatalyst system. In addition, we demonstrate that the predicted biocatalyst behavior at different temperatures and reaction times is consistent with the experimental observations.

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“…Series mechanism is quite versatile and can accommodate many of the observed patterns of enzyme inactivation, so it has gained increasing use to develop sound models for describing enzyme inactivation, especially in the case of immobilized enzymes (Vrábel et al 1997;Azevedo et al 1999;Longo and Combes 1999;Aymard and Belarbi 2000).…”

Section: Series Mechanism Of Inactivationmentioning

confidence: 99%

Enzyme Reactors

Illanes

Altamirano

2008

Enzyme Biocatalysis

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More than 80% of the commercial value of enzymes is linked to their applications as process catalysts. Hydrolytic reactions conducted mainly with the enzyme dissolved in the aqueous medium has been the traditional way of using enzymes, this technology still representing a major share of enzyme processes. However, in recent decades the use of enzymes in organic synthesis has widened its scope of application to unprecedented levels.Enzyme reactors can operate batch-wise or continuously; fed-batch operation has also been proposed (Kumar et al. 1996). Batch processes with the enzymes (usually hydrolases) dissolved in an aqueous reaction medium, despite its wide application have several drawbacks, since enzymes are poorly stable and hard to recover in such systems, leading to low productivity; besides, such processes are characterized by a rather low added value so that process optimization is critical for being and keeping competitive. Poor stability is usually the limiting factor in any enzyme process so that enzyme stabilization during reactor operation is a major concern (Ballesteros et O'Fágáin 2003) and among the many strategies for enzyme stabilization (Illanes 1999) enzyme immobilization is the most relevant (Guisán 2006). Immobilized enzymes can be used in batch processes but in this case the enzyme is recovered to be used in subsequent batches until the accumulated inactivation makes necessary to replace the spent biocatalyst. As a consequence, specific productivity (mass of product/mass of biocatalyst · time of operation) is increased and bioreactor design becomes flexible to suit the particular needs of a given process.Immobilized enzymes, despite the complexities introduced by the heterogeneous nature of the catalytic process, are usually much more stable than their soluble

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Influence of immobilization on the thermal inactivation of yeast invertase

Cited by 25 publications

References 18 publications

Thermal inactivation of exogenous pectin methylesterase in apple and cloudberry juices

Thermal inactivation of exogenous pectin methylesterase in apple and cloudberry juices

Accelerated Biocatalyst Stability Testing for Process Optimization

Enzyme Reactors

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