Combined effects of ultrasound and immobilization protocol on butyl acetate synthesis catalyzed by CALB
It is well established that the performance of lipase B from Candida antarctica (CALB) as catalyst for esterification reactions may be improved by the use of ultrasound technology or by its immobilization on styrene-divinylbenzene beads (MCI-CALB). The present research evaluated the synthesis of but...
Published in: | Molecules |
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Main Authors: | , , , , , , , |
Other Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
Molecular Diversity Preservation International
2014
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Subjects: | |
Online Access: | http://hdl.handle.net/10261/130914 https://doi.org/10.3390/molecules19079562 https://doi.org/10.13039/501100003339 https://doi.org/10.13039/501100003329 https://doi.org/10.13039/501100003593 |
Summary: | It is well established that the performance of lipase B from Candida antarctica (CALB) as catalyst for esterification reactions may be improved by the use of ultrasound technology or by its immobilization on styrene-divinylbenzene beads (MCI-CALB). The present research evaluated the synthesis of butyl acetate using MCI-CALB under ultrasonic energy, comparing the results against those obtained using the commercial preparation, Novozym 435. The optimal conditions were determined using response surface methodology (RSM) evaluating the following parameters: reaction temperature, substrate molar ratio, amount of biocatalyst, and added water. The optimal conditions for butyl acetate synthesis catalyzed by MCI-CALB were: Temperature, 48.8 °C; substrate molar ratio, 3.46:1 alcohol: Acid; amount of biocatalyst, 7.5%; and added water 0.28%, both as substrate mass. Under these conditions, 90% of conversion was reached in 1.5 h. In terms of operational stability, MCI-CALB was reused in seven cycles while keeping 70% of its initial activity under ultrasonic energy. The support pore size and resistance are key points for the enzyme activity and stability under mechanical stirring. The use of ultrasound improved both activity and stability because of better homogeneity and reduced mechanical stress to the immobilized system. This work was supported by grants from CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico), and CTQ2013-41507-R from Spanish MINECO. We would like to thank Novozymes Spain for its comprehensive support of this research, in special Ramiro Martínez (Novozymes, Spain) for kindly supplying the enzymes used in the work. We also thank CNPq (Brazil) for a fellowship to A.M. Silva and FAPERGS (Brazil) for a fellowship to J.S. Alves. A Ph D. fellowship from Spanish Goberment to Miss Garcia-Galan is also acknowledged The help and suggestions from Ángel Berenguer-Murcia (Instituto de Materiales, Universidad de Alicante) are gratefully recognized. We acknowledge support by the CSIC Open Access ... |
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