Effect of Glutaraldehyde Concentration on Catalytic Efficacy of <i>Candida rugosa</i> Lipase Immobilized onto Silica from Oil Palm Leaves

Abstract

Till date, studies that investigated the effect of glutaraldehyde concentration on catalytic efficacy of biocatalyst developed with silica-derived from oil palm leaves (OPL) as support, are unknown. The study presents the preparation of a support consisting of silica extracted from OPL coated over magnetite (G/A/SiO2-M) for the immobilization of Candida rugosa lipase (CRL). Herein, the effect of glutaraldehyde concentration on the catalytic efficacy of immobilized CRL was assessed by the enzymatic production of butyl butyrate as a model. Fourier transform infrared (FTIR) spectra and immobilization parameters indicated that covalent bound CRL on functionalized OPL-derived silica-magnetite composite activated with 4% (v/v) glutaraldehyde solution (100 mM, pH 7.0) (CRL/G/A/SiO2-M) and pretreated in toluene, resulted in a protein loading and an immobilization yield of 68.3 mg/g and 74.3%, respectively. The resultant CRL/G/A/SiO2-M biocatalyst which specific activity was 61.9 U/g catalyzed the esterification production of 76.5% butyl butyrate in just 3 h, as confirmed by analyses of the purified ester using FTIR and 1H NMR spectroscopy. Hence, the finding envisages the promising use of G/A/SiO2-M support fabricated from discarded OPL as a carrier for immobilization and activation of CRL, in conjunction to being a good alternative source of renewable silica.

Electrospun Magnetic Nanocellulose–Polyethersulfone-Conjugated Aspergillus oryzae Lipase for Synthesis of Ethyl Valerate

“…Likewise, the -CH 2 characteristic peak for the propyl group in APTES and glutaraldehyde emerged at 2936 cm −1 . The abovementioned characteristic peaks seen in this study corresponded with previous reports on immobilized lipases[10,42]. The distinctive peaks at 1643, 1566, 1316, and 1234 cm −1 corresponded to amides I, II, and III of the AOL, respectively, implying the successful conjugation of AOL on the MNC/PES surface.…”

“…The amide I and amide II peaks were allotted to the C=O and C=N stretching vibrations and the N-H bending mode. On the other hand, the amide III peak is the stretching vibrations of C-N and C-C and bending vibrations of N-H [10,42] (Figure 1c). A unique peak at 1092 cm −1 for the vibration of C-O and probably PO 4 3− was observed.…”

Operational Stability, Regenerability, and Thermodynamics Studies on Biogenic Silica/Magnetite/Graphene Oxide Nanocomposite-Activated Candida rugosa Lipase

“…The network also protects the attached lipase against physical, chemical, and microbial attacks. The abundant silanol (Si-OH) and siloxane (Si-O-Si) groups at the supports' surface facilitate the effective binding of enzymes to the carriers [4][5][6]. Using graphene oxide (GO) and magnetite (Fe 3 O 4 ) as support components can reduce agglomeration and improve the mechanical and operational stability of immobilized CRL [1,7,8].…”

“…In the beginning, binary nanocomposites were the popular support choice for preparing immobilized lipases [4,5]. A study previously employed the Rhizomucor miehei lipase supported on a chitosan/graphene oxide nanocomposite capable of catalyzing the synthesis of 49.46% geranyl propionate [9].…”

“…Further studies are necessary to gauge the efficacy extent of different nanocomposites to improve the stability and activity of immobilized enzymes. Pertinently, the CRL (hydrolases EC 3.1.1.3) immobilized onto the nanocomposite developed in this study is a versatile enzyme capable of synthesizing high yields of several types of ester [1][2][3][4][5][6]. One major problem is that free CRL is susceptible to deactivation under elevated temperature and pH.…”