Ethyl Butyrate Synthesis Catalyzed by Lipases A and B from Candida antarctica Immobilized onto Magnetic Nanoparticles. Improvement of Biocatalysts’ Performance under Ultrasonic Irradiation

Abstract

The synthesis of ethyl butyrate catalyzed by lipases A (CALA) or B (CALB) from Candida antarctica immobilized onto magnetic nanoparticles (MNP), CALA-MNP and CALB-MNP, respectively, is hereby reported. MNPs were prepared by co-precipitation, functionalized with 3-aminopropyltriethoxysilane, activated with glutaraldehyde, and then used as support to immobilize either CALA or CALB (immobilization yield: 100 ± 1.2% and 57.6 ± 3.8%; biocatalysts activities: 198.3 ± 2.7 Up-NPB/g and 52.9 ± 1.7 Up-NPB/g for CALA-MNP and CALB-MNP, respectively). X-ray diffraction and Raman spectroscopy analysis indicated the production of a magnetic nanomaterial with a diameter of 13.0 nm, whereas Fourier-transform infrared spectroscopy indicated functionalization, activation and enzyme immobilization. To determine the optimum conditions for the synthesis, a four-variable Central Composite Design (CCD) (biocatalyst content, molar ratio, temperature and time) was performed. Under optimized conditions (1:1, 45 °C and 6 h), it was possible to achieve 99.2 ± 0.3% of conversion for CALA-MNP (10 mg) and 97.5 ± 0.8% for CALB-MNP (12.5 mg), which retained approximately 80% of their activity after 10 consecutive cycles of esterification. Under ultrasonic irradiation, similar conversions were achieved but at 4 h of incubation, demonstrating the efficiency of ultrasound technology in the enzymatic synthesis of esters.

The occurrence, enzymatic production, and application of ethyl butanoate, an important flavor constituent

“…It has a significant role in food and flavor industries, and the demand is increasing nowadays 27 . To meet the growing demand for ‘natural’ ethyl butanoate, studies have gradually focused on enzymatic synthesis 28,29 . Using ethyl butanoate as an ester example, this review summarizes most of the works that have been done on ethyl butanoate and will help to gather information and find out the future scopes to improve the production of ethyl butanoate.…”

Lipase From Rhizomucor miehei Immobilized on Magnetic Nanoparticles: Performance in Fatty Acid Ethyl Ester (FAEE) Optimized Production by the Taguchi Method

“…After that time, the biocatalyst was separated from the solution by magnetic decanting and washed with sodium phosphate buffer solution (25 mM and pH 7) until neutrality. To determine the amount of enzyme immobilized on the support, the initial and final concentration of RML in the supernatant of the immobilization suspension was measured ( Bezerra et al, 2017 ; Monteiro et al, 2019b ). The protein concentration was determined using the method described by Bradford (1976) and bovine serum albumin was used as a reference ( Bradford, 1976 ).…”

“…Then 10 mL of APTES was added to the mixture. The system remained for another hour in the ultrasonic bath and after that time, the functionalized nanoparticles were washed four times with ethanol and dried under vacuum (Monteiro et al, 2019b).…”

“…For this, 0.1 g of Fe 3 O 4 @APTES previously dried was put in contact with 100 µL of glutaraldehyde. The mixture remained under constant stirring for 1 h at 25 • C. Then, the mixture was washed three times with sodium phosphate buffer solution (25 mM and pH 7) to remove excess glutaraldehyde (Xie and Ma, 2009;Monteiro et al, 2019b).…”

Optimization of the Production of Enzymatic Biodiesel from Residual Babassu Oil (Orbignya sp.) via RSM

“…For monitoring the percentage of ethyl esters formed by the reaction, the methodology described by [98] and [99] was used, the analytical method of determining the acid index, official methodology [100], was used.…”