Combined Effects of Ultrasound and Immobilization Protocol on Butyl Acetate Synthesis Catalyzed by CALB

Abstract

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 OPEN ACCESSMolecules 2014, 19 9563 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.

Novozym 435: the “perfect” lipase immobilized biocatalyst?

“…Water or glycerin accumulation on Lewatit may be partially reduced using ultrasound and molecular sieves. 44,152,[541][542][543][544][545][546][547][548][549][550] However, the moderate hydrophilicity of the support may complicate the understanding of the results and reuses of the biocatalyst.…”

Ultrasound-assisted lipase catalyzed hydrolysis of aspirin methyl ester

“…Mixing, shearing and mass transfer increase by ultrasound effect lead to high hydrolsysis conversion rates, improving strongly the enzymatic reactions [19][20][21]. Enzyme-ultrasound assisted reactions present several advantages compared with conventional methods namely a decrease of the reaction time, a reduction of the amount of reagents used, a higher yield, and chemo-, region and stereoselectivities of reactions that normally would not occur under normal conditions [18,[22][23][24][25].…”

Biodiesel and flavor compound production using a novel promiscuous cold-adapted SGNH-type lipase (HaSGNH1) from the psychrophilic bacterium Halocynthiibacter arcticus

“…As shown in Fig. 8a, HaSGNH1 could effectively synthesize butyl acetate from 1-butanol and acetic acid based on a gas chromatogram, which is comparable to other enzymes [42,43]. In addition, HaS-GNH1 showed significant catalytic efficiency for butyl butyrate synthesis (Fig.…”