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Heat inactivation of lipase from psychrotrophic Pseudomonas fluorescens P38: Activation parameters and enzyme stability at low or ultra-high temperatures

Biomedical Sciences Research Institute Computer Science Research Institute Environmental Sciences Research Institute Nanotechnology & Advanced Materials Research Institute

Owusu, Richard K, Makhzoum, A and Knapp, JS (1992) Heat inactivation of lipase from psychrotrophic Pseudomonas fluorescens P38: Activation parameters and enzyme stability at low or ultra-high temperatures. Food Chemistry, 44 (4). p. 261. [Journal article]

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URL: http://dx.doi.org/10.1016/0308-8146(92)90048-7

DOI: doi:10.1016/0308-8146(92)90048-7

Abstract

A quantitative model is presented for the heat inactivation of enzymes at low or ultra-high temperatures. As a test of its validity, the heat inactivation of crude or partially purified lipase from Pseudomonas fluorescens, strain P38 (P38 lipase) was investigated. The activation energy (ΔE#), enthalpy (ΔH#), entropy (ΔS#) and Gibbs free energy change (ΔG#) for lipase inactivation at 40–140°C were determined. ΔH# for P38 lipase heat inactivation at 40–60°C, 50–80°C and 90–140°C was 170–221 kJ mol−1, −3 − −20 kJ mol–1 and 44–78 kJ mol−1 respectively. Over these temperature intervals ΔS# was 202–380 J mol−1 K−1, −318 − −375 J mol−1 K−1 and −92 − −186 J mol−1 K−1. ΔG# was 100–115 kJ mol−1 for enzyme inactivation at 40–140°C. The results are consistent with different rate-limiting reactions for P38 lipase heat inactivation at low or ultra-high temperatures. Within a narrow range of (intermediate) temperature, a third rate-limiting reaction may lead to ‘low-temperature inactivation’ phenomena. There was qualitative agreement between experimental results and the current model for enzyme heat inactivation.

Item Type:Journal article
Faculties and Schools:Faculty of Life and Health Sciences
Faculty of Life and Health Sciences > School of Biomedical Sciences
Research Institutes and Groups:Biomedical Sciences Research Institute
Biomedical Sciences Research Institute > Northern Ireland Centre for Food and Health (NICHE)
ID Code:16956
Deposited By:Dr Richard Owusu-Apenten
Deposited On:01 Feb 2011 13:25
Last Modified:01 Feb 2011 13:25

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