BIORESOURCE TECHNOLOGY
·
2017
·
IF 5.651
Guochao Xu,Yaping Zhang,Yue Wang,Ye Ni
In this work, genome hunting strategy was adopted in screening for reductases from Candida glabrata . A total of 37 putative reductases were successfully expressed in E. coli BL21(DE3). A substrate library containing 32 substrates was established for characterization of each reductase by average specific activity and Shannon-Wiener index. Among them, Cg26 was identified with the highest efficiency and wider substrate spectrum in the reduction of prochiral ketones, with average activity and Shannon-Wiener index of 8.95 U·mg −1 and 2.82. Cg26 is a member of ‘extended’ short chain dehydrogenase/reductase superfamily. Ni 2+ could improve its activity. As much as 150 g·L −1 ethyl 2-oxo-4-phenylbutyrate could be completely converted by 10 g·L −1 Cg26. This study provides evidence for this newly identified Cg26 in the preparation of chiral secondary alcohols.
研究领域:
生物化学
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酶工程
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合成生物学
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DOI
PubMed
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2013
·
IF 1.304
Yi Hu,Xiangjun Jiang,Suwen Wu,Ling Jiang,He Huang
Vitamin E succinate was synthesized by interfacial activated Candida rugosa lipase (CRL) encapsulated in sol-gel materials. The effects of various immobilization parameters were investigated. The optimum conditions were found to consist of n -propyltrimethoxysilane/tetraethoxysilane molar ratio = 1/1, water/silane molar ratio ( R value) = 20, lipase loading = 0.5 mg/ml sol, and PEG400 loading = 12 μl/ml sol. Compared with free enzymes, sol-gel encapsulated enzymes kept its activity of 70.58% and achieved 2.6-fold increased stability after 18 h incubation in phosphate buffer (0.025 mol/L, pH = 7.0) at 50 °C. Based on the interfacial characteristics of CRL, five kinds of surfactants were used for activation. The results demonstrate that olive oil was the most effective in activating CRL. The esterification activity of vitamin E succinate synthesis by interfacial activated CRL encapsulated in sol-gel materials reached up to 6.7-fold and 1.43-fold that of free enzyme and non-interfacial activated enzyme, respectively.
研究领域:
生物化学
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酶工程
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DOI
高影响因子
BIOTECHNOLOGY PROGRESS
·
2021
·Vol. 38
·期 1
·e3218
·
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.
研究领域:
生物化学
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酶工程
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材料科学
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PubMed
高影响因子
BIOPROCESS AND BIOSYSTEMS ENGINEERING
·
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.
研究领域:
生物化学
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酶工程
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工业生物技术
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高影响因子
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2020
·Vol. 192
·期 2
·392-414
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IF 2.277
Chen Sunni,Li Jing,Fu Zejian,Wei Guohua,Li Hongyan,Zhang Bin,Zheng Liufeng,Deng Zeyuan
Phytosterols are regarded as compounds able to reduce total and low-density lipoprotein cholesterol in the blood, and their esterified derivatives could help to improve the effectiveness of this function. In the present study, the water/sodium 1,4-bis-2-ethylhexylsulfosuccinate (AOT)/isooctane reverse micelle (RM) system was set up as a reaction medium for Candida rugosa lipase AY30 (CRL AY30) to synthesize β-sitosterol laurate (β-SLE). The product was identified by TLC, FT-IR, and HPLC–APCI–QqQ–MS/MS and quantified by HPLC. Through stepwise optimization, it was found that CRL AY30 had the highest activity in the water/AOT/isooctane RM system where 50 mM PBS with a pH of 7.5 was adopted as water core to carry CRL AY30, and the proportion of [CRL AY30] (mg/mL), [water] (mM), and [AOT] (mM) was set in 3:375:25, respectively, in isooctane. After screened with single-factor experiments, the esterification reaction conditions in the CRL AY30–water/AOT/isooctane RM system were further optimized by the response surface method as follows: the mole ratio of β-sitosterol to lauric acid of 1:3.5 (25 mM β-sitosterol), the enzyme load of 18% (w/w total reactants), the reaction temperature of 47 °C, and the reaction time of 48 h. As a result, the maximum esterification rate was up to 88.12 ± 0.79%.
研究领域:
生物化学
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食品科学
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制药工程
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PubMed
高影响因子
ENZYME AND MICROBIAL TECHNOLOGY
·
2023
·
IF 3.4
Liwen Shu,Xin Zheng,Shuhua Qi,Shuizhi Lin,Yinghua Lu,Chuanyi Yao,Xueping Ling
Docosahexaenoic acid (DHA) enriched with phospholipids (PLs) (DHA-PLs) is a type of structured PL with good physicochemical and nutritional properties. Compared to PLs and DHA, DHA-PLs has higher bioavailability and structural stability and many nutritional benefits. To improve the enzymatic synthesis of DHA-PLs, this study investigated the preparation of phosphatidylcholine (PC) enriched with DHA (DHA-PC) via enzymatic transesterification of algal oil, which is rich in DHA-triglycerides, using immobilized Candida antarctica lipase B (CALB). The optimized reaction system incorporated 31.2% DHA into the acyl chain of PC and converted 43.6% PC to DHA-PC within 72 h at 50 °C, 1:8 PC: algal oil mass ratio, 25% enzyme load (based on total substrate mass), and 0.02 g/mL molecular sieve concentration. Consequently, the side reactions of PC hydrolysis were effectively suppressed and products with high PC content (74.8%) were produced. Molecular structure analysis showed that exogenous DHA was specifically incorporated into the sn-1 site of the PC by immobilized CALB. Furthermore, the evaluation of reusability with eight cycles showed that the immobilized CALB had good operational stability in the present reaction system. Collectively, this study demonstrated the applicability of immobilized CALB as a biocatalyst for synthesizing DHA-PC and provided an improved enzyme-catalyzed method for future DHA-PL synthesis.
研究领域:
食品科学
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生物化学
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PubMed
高影响因子
Molecular Catalysis
·
2021
·
IF 5.062
Yu Han,Xinying Zhang,Liangyu Zheng
In our previous study, the soluble expression of recombinant Candida antarctica lipase B ( r CalB) in E. coli is achieved through fusion with polyamino acid tails. The present study showed that even in the form of inclusion bodies ( r CalB-IBs), r CalB-IBs were still active towards enzyme-catalyzed reactions. r CalB-IBs could be directly crosslinked by the oxidized dextran in the presence of Fe 3 O 4 nanoparticles to obtain magnetic aggregates ( r CalB-mclIBs), and an activity recovery of 113.9 % ± 2.2 % could be achieved under optimized conditions. The obtained r CalB-mclIBs exhibited excellent thermal and storage stabilities, and a good tolerance in changing pH environmental. r CalB-mclIBs could be effectively recycled and could retain 85.4 % ± 2.5 % of its initial activity, and an e.e. p of 84.4 % ± 2.2 % in ( R , S )-NEMPA-ME hydrolysis was observed after the 10th cycle. After the application of r CalB-mclIBs into a promiscuous carbon–carbon bond-forming reaction, the MBH and the Aldol products could be obtained simultaneously. This study provides a simple and inexpensive strategy to highlight the application potential of r CalB-IBs as a biocatalyst.
研究领域:
生物化学
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酶工程
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合成生物学
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DOI
高影响因子
BIOPROCESS AND BIOSYSTEMS ENGINEERING
·
2024
·
IF 3.5
Liu Jiale,Zhao Shufan,Wei Wan,Yu Shupeng,Wang Zhao,Zheng Jianyong
Lipase is one of the most widely studied and applied biocatalysts. Due to the high enzyme leakage rate of the immobilization method of physical adsorption, we propose a new lipase immobilization method, based on the combination of macroporous resin adsorption and organic polymer coating. The immobilized Candida antarctica lipase B (CALB@resin-CAB) was prepared by combining the macroporous resin adsorption with cellulose acetate butyrate coating, and its structure was characterized by various analytic methods. Immobilized lipase was applied for biodiesel production using acidified palm oil as the starting material, the conversion rate achieved as high as 98.5% in two steps. Furthermore, the immobilized lipase displayed satisfactory stability and reusability in biodiesel production. When the aforementioned reaction was carried out in a continuous flow packed bed system, the yield of biodiesel was 94.8% and space–time yield was 2.88 g/(mL∙h). The immobilized lipase CALB@resin-CAB showed high catalytic activity and stability, which has good potential for industrial application in the field of oil processing.
研究领域:
生物化学
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酶工程
·
可再生能源
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高影响因子
JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC
·
2016
·
IF 2.189
Yicheng Bi,Min Yu,Haiyan Zhou,Hua Zhou,Ping Wei
In our study, oleyl oleate was synthesized through enzymatic esterification of oleic acid with oleyl alcohol using Candida rugosa lipase (CRL) immobilized on macroporous resin in a solvent-free system. CRL was immobilized flexibly on the support via aldehyde-dextran, and the effectiveness of aldehyde-dextrans, as cross-linking agents with different molecular weights, was compared and discussed. The impact of various factors, such as different molecular weights of dextran , molar ratio between oleic acid and oleyl alcohol, and the temperature and stability of enzymes, on esterification was investigated as well. Our study indicated that lipase immobilized by 20000 Da dextran yielded the best result. The optimal condition to produce oleyl oleate using immobilized CRL was found in our study and turned out to be molar ratio of 1, reaction temperature of 40 °C, and a 12-h reaction time to reach reaction equilibrium. Under the optimal reaction conditions, a high percentage yield of ester was achieved (92.6%). The immobilized CRL also reached a conversion rate of 86.7% with excellent stability even after 8 cycles.
研究领域:
生物化学
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酶工程
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高影响因子
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.
研究领域:
生物技术
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化学工程
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材料科学
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DOI
PubMed
高影响因子
Journal of Oleo Science
·
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.
研究领域:
生物技术
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酶工程
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化学工程
·
生物化学
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PubMed
高影响因子
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.
研究领域:
生物化学
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纳米技术
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酶工程
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）