Polyethyleneimine-modified superparamagnetic Fe3O4 nanoparticles for lipase immobilization: Characterization and application

Partial Purification and Characterization of a Thermoalkalophilic Lipase Originated from Bacillus atrophaeus FSHM2 and its Application for Ester Synthesis

“…6b). The same results were reported by Khoobi et al (2015), who determined 72.9% conversion of valeric acid using the immobilized lipase of Thermomyces lanuginosa on polyethyleneimine grafted magnetic nanoparticles compared to that of the solvent-free medium (28.9%). The positive effect of organic solvents on esterification reactions could be attributed to the shifting of the reaction equilibrium toward ester synthesis by total transfer of ester to the organic phase (Khoobi et al, 2015).…”

“…Application of the partially purified lipase for the esterification of valeric acid: The partially purified lipase was used as the biocatalyst for the esterification of valeric acid in the presence of ethanol or methanol in both solvent-free and organic solvent (n-hexane, xylene, isopropyl alcohol and n-butanol) media according to the method described by Khoobi et al (2015). In the case of the solvent-free system, the reaction mixture (final volume of 10 mL) was prepared by adding valeric acid solution in ethanol or methanol (acid/alcohol molar ratios of 2:1, 1:1, 1:2, 1:3, 1:4 and 1:5) to the partially purified lipase (10 U mLG 1 , in phosphate buffer 0.1 M pH 9) followed by incubation at 50°C and 100 rpm for 1, 2, 4, 6, 12 and 24 h. For the non-aqueous medium, 4 mmol of ethanol or methanol and 1 mmol of valeric acid were dissolved in 10 mL of each applied anhydrous organic solvent (n-hexane, xylene, isopropyl alcohol and n-butanol) and the partially purified lipase was added to the reaction mixture and shaken at 50°C and 100 rpm for 1, 2, 4, 6, 12 and 24 h. Thereafter, the alkalimetric titration of the unreacted acid using 0.1 N of NaOH in the presence of phenolphthalein as an indicator was applied for determining the amount of the produced ester.…”

“…DVL2. Khoobi et al (2015) achieved the highest esterification yield (using the immobilized lipase of Thermomyces lanuginosa on polyethyleneimine-modified superparamagnetic Fe 3 O 4 ) at the molar ratio of 1:4 valeric acid/ethyl alcohol. The obtained results of esterification experiments (Fig.…”

Incorporation of superparamagnetic nanoparticles into poly(urea-urethane) nanoparticles by step growth interfacial polymerization in miniemulsion

“…improves stability against aggregation preserving the material in the range of superparamagnetism (single magnetic domain); and the polymer shell can be further functionalized or loaded with a drug [5].Among the applications of MNPs encapsulated in a polymer shell, the most featured ones are: biomedical applications, including cellular therapy, diagnostic applications [6,7], MRI contrastagents [8], hyperthermia [9], drug delivery [10] and for enzymes immobilization [11][12][13][14]with application in biocatalysis [15] including biodiesel production [16,17] andenzymatic synthesis of flavors [18].…”

“…Co-precipitation [18][19][20] thermal decomposition [21]and microemulsion [22]techniques have been reported for MPNs synthesis. The coprecipitation is the most commonly employed technique presenting several advantages as simplicity and high efficiency of the chemical reaction [23].…”