Immobilization of Candida rugosa Lipase on Glutaraldehyde‐Activated Fe₃O₄@Chitosan as a Magnetically Separable Catalyst for Hydrolysis of Castor Oil

Abstract

In this study, the catalyzed hydrolysis of castor oil by Candida rugosa lipase (CRL) immobilized on glutaraldehyde‐activated magnetic Fe3O4@chitosan is investigated. Magnetic Fe3O4 is prepared by hydrothermal method and coated with chitosan (CS). Next, CRL is immobilized on Fe3O4@chitosan using glutaraldehyde as a cross‐linking reagent. The prepared Fe3O4@CS@CRL is confirmed by scanning electron microscopy (SEM), X‐ray powder diffraction (XRD), vibrating sample magnetometry (VSM), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA). The response surface methodology (RSM) based on the Box–Behnken design is used to evaluate and optimize the hydrolysis reaction variables. The optimum reaction conditions for the hydrolysis of castor oil by the Fe3O4@CS@CRL heterogeneous catalyst are found to be a water/oil ratio of 1.60:1, pH of 7.05, reaction temperature of 34 °C, and lipase concentration of 3.27%; under these conditions, the hydrolysis conversion of castor oil reached 46.81%. Moreover, the immobilized lipase showed high stability with no appreciable loss in its activity after three consecutive cycles. Practical Applications: RSM is found to be a useful technique for optimizing hydrolysis of castor oil. The high conversion of the hydrolysis of castor oil indicates that the Fe3O4@CS@CRL have potential to be used in preparing ricinoleic acid from castor oil. Ricinoleic acid have the potential to be used in printing ink as a pigment and dye disperser, plasticizers, surfactants, lubricants, and other valuable products. Ricinoleic acid can be used in pigment and dye disperser in printing ink, sebacic acid, azelaic acid, heptaldehyde, plasticizers, surfactants, lubricants, and other valuable products. Hydrolysis of castor oil catalyzed by Candida rugosa lipase (CRL) immobilized on glutaraldehyde‐activated magnetic Fe3O4@chitosan is investigated. The response surface methodology (RSM) based on the Box–Behnken design is used to evaluate and optimize the hydrolysis reaction variables. Fe3O4@CS@CRL can be easily separated from the suspension using an external strong magnet. Fe3O4@CS@CRL have potential to be used in preparing ricinoleic acid from castor oil.

Substrate-Specificity ofCandida rugosaLipase and Its Industrial Application

“…For example, commercial CRL hydrolyzes butter oil in the absence of organic solvents and showed higher specificity toward butyric acid relative to Pseudomonas fluorescein lipase after 3 h of hydrolysis at 40 °C (22 vs 8 mol %, respectively) rendering it an ideal choice for a biological catalyst to generate useful dairy flavor profiles . Furthermore, immobilized CRL has been used for the enrichment of the production of omega-3 polyunsaturated fatty acids (eicosapentaenoic acid and docosahexaenoic acid) through hydrolysis of fish oil , or the hydrolysis of different plant oils to produce linoleic acid (LA), used as a flavor precursor, e.g., castor oil (conversion of 47%), safflower oil (conversion of 84%) and borage oil (conversion of 46%) …”

Immobilization of Interfacial Activated Candida rugosa Lipase Onto Magnetic Chitosan Using Dialdehyde Cellulose as Cross-Linking Agent

“…The synthesis of supports Fe 3 O 4 -CS, Fe 3 O 4 -CS-GA, and Fe 3 O 4 -CS-DAC were referred to the previously reported literature with a minor modification ( Kim et al, 2017 ; Zhao et al, 2018 ).…”

Recent Trends in Biomaterials for Immobilization of Lipases for Application in Non-Conventional Media

“…The coating of magnetic nanoparticles with biopolymers like chitosan protects them against erosion and provides appropriate functional groups [14]. For example, magnetic Fe 3 O 4 nanoparticles were prepared by the hydrothermal method and coated with chitosan activated with glutaraldehyde and then used to immobilize CRL [66]. The biocatalyst was used to hydrolyze castor oil, with a degree of hydrolysis of 46% being obtained in 60 h at 34 • C. The activity was not stable: in the fourth hydrolysis cycle, the degree of hydrolysis was only 30%.…”

“…The biocatalyst was used to hydrolyze castor oil, with a degree of hydrolysis of 46% being obtained in 60 h at 34 • C. The activity was not stable: in the fourth hydrolysis cycle, the degree of hydrolysis was only 30%. The authors suggested that the loss of activity was due to "irreversible" adsorption of substrate and product on the support, since they washed the biocatalyst with tertiary butyl alcohol and PBS (phosphate-buffered saline 0.02 M, pH 7.0) to remove any substrate or product that had been retained on the support [66].…”