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Characterization of the lipase immobilized on Mg–Al hydrotalcite for biodiesel

Paper ID Volume ID Publish Year Pages File Format Full-Text
35475 45092 2009 8 PDF Available
Title
Characterization of the lipase immobilized on Mg–Al hydrotalcite for biodiesel
Abstract

Immobilization of Saccharomyces cerevisiae lipase by physical adsorption on Mg–Al hydrotalcite with a Mg/Al molar ratio of 4.0 led to a markedly improved performance of the enzyme. The immobilized lipase retained activity over wider ranges of temperature and pH than those of the free lipase. The immobilized lipase retained more than 95% relative activity at 50 °C, while the free lipase retained about 88%. The kinetic constants of the immobilized and free lipases were also determined. The apparent activation energies (Ea) of the free and immobilized lipases were estimated to be 6.96 and 2.42 kJ mol−1, while the apparent inactivation energies (Ed) of free and immobilized lipases were 6.51 and 6.27 kJ mol−1, respectively. So the stability of the immobilized lipase was higher than that of free lipase. The water content of the oil must be kept below 2.0 wt% and free fatty acid content of the oil must be kept below 3.5 mg KOH g [oil]−1 in order to get the best conversion. This immobilization method was found to be satisfactory to produce a stable and functioning biocatalyst which could maintain high reactivity for repeating 10 batches with ester conversion above 81.3%.

Keywords
Immobilized lipase; Hydrotalcite; Biodiesel; Reuse; Saccharomyces cerevisiae
First Page Preview
Characterization of the lipase immobilized on Mg–Al hydrotalcite for biodiesel
Publisher
Database: Elsevier - ScienceDirect
Journal: Process Biochemistry - Volume 44, Issue 8, August 2009, Pages 791–798
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering