Catalysts
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2021
·Vol. 11
·期 12
·1463
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IF 4.146
Honghai Wang,Wenda Yue,Shuling Zhang,Yu Zhang,Chunli Li,Weiyi Su
Silica xerogels have been proposed as a potential support to immobilize enzymes. Improving xerogels’ interactions with such enzymes and their mechanical strengths is critical to their practical applications. Herein, based on the mussel-inspired chemistry, we demonstrated a simple and highly effective strategy for stabilizing enzymes embedded inside silica xerogels by a polydopamine (PDA) coating through in-situ polymerization. The modified silica xerogels were characterized by scanning and transmission electron microscopy, Fourier tranform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and pore structure analyses. When the PDA-modified silica xerogels were used to immobilize enzymes ofCandida antarcticalipase B (CALB), they exhibited a high loading ability of 45.6 mg/gsupport, which was higher than that of immobilized CALB in silica xerogels (28.5 mg/gsupport). The immobilized CALB of the PDA-modified silica xerogels retained 71.4% of their initial activities after 90 days of storage, whereas the free CALB retained only 30.2%. Moreover, compared with the immobilization of enzymes in silica xerogels, the mechanical properties, thermal stability and reusability of enzymes immobilized in PDA-modified silica xerogels were also improved significantly. These advantages indicate that the new hybrid material can be used as a low-cost and effective immobilized-enzyme support.Keywords:Candida antarcticalipase B;silica xerogel;enzyme immobilization;polydopamine;modification
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FOOD CHEMISTRY
·
2023
·
IF 8.8
Danyu Lv,Muyun Wang,Wanjun He,Jieli Wu,Xiaoyue Liu,Yongguang Guan
Bixin has desirable bioactivities but poor water solubility, which limits its practical applications. Enzymatic transesterification of methyl to alditol groups in bixin by Candida antarctica lipase B (CALB) improves bixin water solubility. Herein, magnetic CALB nanoreactors with diameter of 11.7 nm and CALB layer thickness of 3.5 nm were developed by covalently linking CALB onto silicon covered Fe 3 O 4 nanoparticles. The CALB loading capacity in nanoreactors achieved 30%. The Michaelis constant ( Km ) and maximum reaction rate of magnetic CALB nanoreactors were 56.1 mmol/L and 0.2 mmol/(L·min). Magnetic CALB nanoreactors could circularly catalyze bixin-maltitol ester synthesis and keep catalytic efficiency of 62.6% after eight repetitive enzymatic reactions. Additionally, the optimal bixin-maltitol ester synthesis procedure was heating bixin-maltitol mixture at molar ratio of 1:7 in anhydrous 2-methyl-2-butanol-dimethylsulfoxide (8:2, v/v) at 50 °C for 24 h. Bixin-maltitol ester showed improved water solubility at pH 5.5 and 7.0.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2022
·
IF 8.025
Xue Shi,Xiaoli Qin,Yunxiang Dai,Xiong Liu,Weifei Wang,Jinfeng Zhong
The catalytic activity of Candida antarctica lipase B (CALB) immobilized on modified cellulose nanocrystals (CNC) with different hydrophobicity was investigated using experimental and theoretical approaches. Firstly, the modified CNC were characterized by multi-spectroscopic methods, water contact angle, scanning electron microscopy and thermogravimetric analysis. Moderately hydrophobic CNC were found to be an optimal support for CALB immobilization. Secondly, model systems contained a CALB molecule and different numbers of modified CNC molecules ( [email protected] , [email protected] and [email protected] ) were prepared for molecular dynamics (MD) simulation. Root-mean-square fluctuation values (0.61–2.61 Å) of lid region were relatively high in [email protected] , indicating that modified CNC with moderate hydrophobicity favored forming a lid-open conformation of CALB. Finally, the esterification of oleic acid catalyzed by the immobilized CALB showed higher conversion (54.68 %) than free CALB (12.98 %). Insights into modified CNC with tunable properties provided by this study may be a potential support for improving the catalytic performance of lipases.
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Journal of Oleo Science
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2022
·
IF 1.628
Lihong He,Jiawei Zheng,Siting Feng,Li Xu,Nanjing Zhong
In this study, lipase A from Candida antarctica (CALA) was immobilized onto the macroporous resin NKA-9. Immobilization conditions (pH, time and CALA concentration) were studied, enzymatic activity and immobilization efficiency (IE) up to 968.89 U/g and 53.19% were respectively obtained under optimal conditions (immobilization pH 5.0, time 5 h and CALA concentration at 30 mg/mL). Then, the NKA-9 supported CALA (CALA@NKA-9) samples were used to catalyze glycerolysis in solvent-free system. With 0.25 g of the present CALA@NKA-9 (soybean oil 3.52 g and glycerol 0.184 g) and after 12 h reaction at 50 °C, diacylglycerols (DAG) content up to 64.37% and triacylglycerols (TAG) conversion at 83.33% were obtained. The relationship between temperature and TAG conversion was LnV 0 = 13.9310-6.4212/T for CALA@NKA-9. Meanwhile, the activation energy (Ea) of CALA@NKA-9 was calculated to be 53.39 kJ/mol. In addition, reusability in the glycerolysis reaction was also evaluated, and 57.82% of the initial glycerolysis activity was retained after 9 consecutive applications. Furthermore, the CALA@NKA-9 was also used to catalyze the esterification (esterification of fatty acids with glycerol), however, the present CALA@NKA-9 cannot initiate the esterification. Therefore, the present CALA@NKA-9 is shown to be potential for DAG production through glycerolysis reaction.
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BIOTECHNOLOGY PROGRESS
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2021
·Vol. 38
·期 1
·e3218
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IF 2.681
Xiao-Jian Zhang,Feng-Yu Qi,Jia-Mei Qi,Fei Yang,Jiang-Wei Shen,Xue Cai,Zhi-Qiang Liu,Yu-Guo Zheng
The Candida antarctica lipase B (CALB) was embedded in the metal-organic framework, zeolitic imidazolate framework-8 (ZIF-8), and applied in the enzymatic synthesis of L -ascorbic acid palmitate (ASP) for the first time. The obtained CALB@ZIF-8 achieved the enzyme loading of 80 mg g −1 with 11.3 U g −1 (dry weight) unit activity, 59.8% activity recovery, and 92.7% immobilization yield. Under the optimal condition, ASP was synthesized with over 75.9% conversion of L -ascorbic acid in a 10-batch reaction. Continuous synthesis of ASP was subsequently performed in a packed bed bioreactor with an outstanding average space–time yield of 58.1 g L −1 h −1 , which was higher than ever reported continuous ASP biosynthesis reactions.
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RSC Advances
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2017
·Vol. 7
·期 21
·12518-12523
·
IF 3.108
Pengfei Zhou,Xuping Wang,Bo Yang,Frank Hollmann,Yonghua Wang
Epoxides are important synthetic intermediates for the synthesis of a broad range of industrial products. This study presents a promising solution to the current limitation of enzyme instability. By using simple deep eutectic solvents such as choline chloride/sorbitol, significant stabilization of the biocatalyst has been achieved leading to more robust reactions while using environmentally more acceptable solvents as compared to ionic liquids.
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PROCESS BIOCHEMISTRY
·
2024
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IF 3.7
Shihao Liang,Wei Zhuang,Zhenfu Wang
In this work, isocyanate-based strategy was developed for efficient immobilization of Candida antarctica lipase B (CALB). Of 41 commercial resins, EP109 was chosen and hydrophobized with hydroxyl-terminated polydimethylsiloxane (HTPDMS) for tert-butyl isocyanate (tBIC)-based CALB immobilization due to high loading amount and specific activity. The tBIC-based strategy exhibited shorter immobilization time, higher loading and activity than adsorption strategy by hydrophobic interaction. When compared with free CALB, EP109-HTPDMS-tBIC@CALB owned improved stability (against acid, alkali, and heat) and storability. Subsequently, EP109-HTPDMS-tBIC@CALB was employed in the bio-synthesis of 1,3-diacylglycerol in a solvent-free system with a yield of 76.31%, which was higher than commercial Novozym 435 (53.93%). EP109-HTPDMS-tBIC@CALB exhibited 76.34% of residual activity after 20 repeat uses.
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FIBERS AND POLYMERS
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2018
·Vol. 19
·期 8
·1611-1617
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IF 1.353
Wang Cuie,Wang Ning,Liu Xinhua,Wan Peng,He Xinwei,Shang Yongjia
We propose a green synthesis of benzopyran compound based on immobilized lipase. Firstly, by using a combined electrospun membrane and biocompatible chitosan, we show that the chitosan-functionalized electrospun PMA-co-PAA fibrous membrane can provide effective anchoring sites for immobilization of the Candida antarctica lipase B (CALB), and a maximum loading amount of CALB (152 mg/g) can be achieved. Then, the resulting membrane displays enhanced stability in catalyzing Knoevenagel condensation reaction of salicylaldehyde with active methylene compound in mixed aqueousorganic media. The catalytic activity and stability of the CALB on chitosan-modified fiber is better than its non-immobilized counterpart. Furthermore, this immobilize CALB catalyst still retained about 45 % of the initial activity after 5 cycles, which potentially had implications for the design of “green” enzyme catalyst for sustainable organic synthesis.
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BIOPROCESS AND BIOSYSTEMS ENGINEERING
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2022
·Vol. 45
·期 4
·749-759
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IF 3.434
Zhang Xiao-guang,Xue Yu,Lu Ze-ping,Xu Hua-jin,Hu Yi
In this study, a series of proline ionic liquids with different lengths of hydrophobic alkyl on the side chain were used to modify the Candida Antarctic lipase B (CALB). The catalytic activity, thermal stability and tolerance to methanol and DMSO of the modified enzyme were all improved simultaneously. The optimum temperature changed from 55 to 60 ℃. The hydrophobicity and anion type of the modifier have important influence on the catalytic performance of CALB. CALB modified by [ProC 12 ][H 2 PO 4 ] has a better effect. Under the optimal conditions, its hydrolysis activity was 3.0 times than that of the native enzyme, the catalytic efficiency Kcat/Km improved 2.8 times in aqueous phase, and the tolerance to organic solvent with strong polarity (50% methanol 2 h) was increased by 6.8 times. Fluorescence spectra and circular dichroism (CD) spectroscopy showed that the introduction of ionic liquids changed the microenvironment near the fluorophores of the enzyme protein, the α-helix decreased and β-sheet increased in the secondary structure of the modified enzymes. The root mean square deviation (RMSD), residue root mean square fluctuation (RMSF), radius of gyration (Rg), and solution accessible surface area (SASA) of [ProC 2 ][Br]-CALB, [ProC 12 ][Br]-CALB and native CALB were obtained for comparison by molecular dynamics simulation. The results of dynamics simulation were in good agreement with enzymology experiment. The introduction of ionic liquids can keep CALB in a better active conformation, and proline ionic liquids with long hydrophobic chains can significantly improve the surface hydrophobicity and overall rigidity of CALB. This research offers a new idea for rapid screening of efficient modifiers and provision of enzymes with high stability and activity for industrial application.
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Frontiers in Bioengineering and Biotechnology
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2022
·
IF 6.064
Xue Yu,Zhang Xiao-Guang,Lu Ze-Ping,Xu Chao,Xu Hua-Jin,Hu Yi
Various betaine ionic liquids composed of different chain lengths and different anions were designed and synthesized to modify Candida antarctica lipase B (CALB). The results showed that the catalytic activity of all modified lipases improved under different temperature and pH conditions, while also exhibiting enhanced thermostability and tolerance to organic solvents. With an increase in ionic liquid chain length, the modification effect was greater. Overall, CALB modified by [BetaineC16][H2PO4] performed best, with the modified CALB enzyme activity increased 3-fold, thermal stability increased 1.5-fold when stored at 70°C for 30 min, with tolerance increased 2.9-fold in 50% DMSO and 2.3-fold in 30% mercaptoethanol. Fluorescence and circular dichroism (CD) spectroscopic analysis showed that the introduction of an ionic liquid caused changes in the microenvironment surrounding some fluorescent groups and the secondary structure of the CALB enzyme protein. In order to establish the enzyme activity and stability change mechanisms of the modified CALB, the structures of CALB modified with [BetaineC4][Cl] and [BetaineC16][Cl] were constructed, while the reaction mechanisms were studied by molecular dynamics simulations. Results showed that the root mean square deviation (RMSD) and total energy of modified CALB were less than those of native CALB, indicating that modified CALB has a more stable structure. Root mean square fluctuation (RMSF) calculations showed that the rigidity of modified CALB was enhanced. Solvent accessibility area (SASA) calculations exhibited that both the hydrophilicity and hydrophobicity of the modified enzyme-proteins were improved. The increase in radial distribution function (RDF) of water molecules confirmed that the number of water molecules around the active sites also increased. Therefore, modified CALB has enhanced structural stability and higher hydrolytic activity.
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FOOD CHEMISTRY
·
2023
·
IF 8.8
Lili Yin,Kunpeng Gao,Xiangzhao Mao,Yang Hu
Lipase B from Candida antarctica (CALB) plays a prominent role as a biocatalyst in several industries, especially for biphasic conversion of functional lipids. Herein, an amphiphilic Janus halloysite nanosheet (JHNS) was fabricated and employed simultaneously as a solid surfactant for stabilizing Pickering emulsion and as a carrier for immobilizing CALB, with the aim to realize highly efficient biphasic bioconversion. The obtained JHNS could stabilize Pickering emulsion for at least 7 days. Immobilization of CALB on JHNS improved the substrate affinity, catalytic efficiency, thermal stability, and alkaline tolerance of the enzyme. Moreover, JHNS-based immobilized CALB was exploited as a biocatalytic platform for the conversion of retinyl acetate, with almost twice increase in conversion efficiency. Taken together, the JHNS-based immobilized CALB paves the way for the design of efficient biphasic conversion system for the production of added-value lipids.
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ENZYME AND MICROBIAL TECHNOLOGY
·
2017
·
IF 2.502
Kun Zhang,Zhiyou Pan,Zhoujian Diao,Shuli Liang,Shuangyan Han,Suiping Zheng,Ying Lin
Kinetic resolution of sec -alcohols is a green process with biocatalyst. Candida antarctica lipase B (CALB) displayed on Pichia pastoris cell-surface (Pp-CALB) was characterized in kinetic resolution of sec -alcohols with different structures. The reaction parameters including acyl donors, molar ratio of substrates, solvents and temperatures were examined with 2-octanol as model substrate. 47.4% molar conversion of 2-octanol and 99.7% ee p were obtained after a 5 h reaction with Pp-CALB, and 90% of its original activity still remained after being reused for 10 cycles. Pp-CALB was then used to several sec -alcohols and it showed great enzymatic activity and enantioselectivity to all tested sec -alcohols, more than 93.1% of ee p . The enantioselective characteristics of Pp-CALB catalysed sec -alcohols with different structures were compared with Novozyme 435 which was almost the same. Solvent free system as one way of green chemistry was applied to Pp-CALB and Pp-CALB showed great catalytic activity and enantioselectivity. Pp-CALB was potential biocatalyst of high enzymatic activity and enantioselectivity using in resolution of sec -alcohols.
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