INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2018
·
IF 3.909
Jiandong Cui,Baoting Sun,Tao Lin,Yuxiao Feng,Shiru Jia
Enzyme immobilization on the external surface of solid supports is a commonly adopted method to improve stability and reuse for continuous operations, which, however, is prone to cause the enzyme denaturation due to no carriers protection. Herein, we describe enzyme-shielding strategy to prepare hybrid organic/inorganic nanobiocatalysts; it exploits the self-assembly of silane building blocks at the surface of immobilized enzymes on Fe 3 O 4 /silica core-shell nanospheres to grow a protective silica layer. The silica shell around the immobilized enzyme particles provides a “shield” to protect from biological, thermal and chemical degradation for enzyme. As a result, the recycling of the immobilized catalase with a protective silica layer was improved remarkably compared with immobilized catalase without a protective silica layer. The immobilized catalase with a protective silica layer still remained 70% of their original activity after 9 cycles, whereas the immobilized catalase without a protective silica layer only retained 20% of their original activity. Moreover, the immobilized catalase with a protective silica layer exhibited significantly enhanced resistance to denaturing stresses (such as proteolytic agent, denaturants, and heat). Therefore, the enzyme-shielding strategy showed promising applications for preparing obtain stable and recycled nanobiocatalyst.
研究领域:
纳米生物技术
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酶工程
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材料科学
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生物催化
·
药物递送系统
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DOI
高影响因子
JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC
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2014
·
IF 2.745
Teng Zhang,Xiao-Ling Xu,Yi-Ning Jin,Jian Wu,Zhi-Kang Xu
Carbon nanotubes are widely applied in electronics, which offers great potential for enhancing the activity of redox enzyme. In this work, polyimide (PI) was blended with multiwalled carbon nanotubes (MWCNTs) and then electrospun into nanofibers for the immobilization of horseradish peroxidase (HRP), a redox enzyme. SEM and TEM were used to characterize the surface morphology of the PI/MWCNTs nanofibers and to analyze the protruding parts induced by the blending of MWCNT. The results indicate that, compared to the virgin PI nanofibers, the blending of MWCNTs increases the retention activity of immobilized HRP from 2.38% to 12.50%. Circular dichroism and UV–vis molecular absorption spectrometry were used to explore the interactions between HRP and MWCNTs . It seems that MWCNTs increase the enzyme activity by the facilitation of electron transfer among the catalytic intermediates “HRP I”, “HRP II” and MWCNTs.
研究领域:
生物化学
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纳米生物技术
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酶工程
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生物材料
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分析化学
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DOI
高影响因子
JOURNAL OF APPLIED MICROBIOLOGY
·
2019
·Vol. 126
·期 1
·127-137
·
IF 2.683
Zhang H.‐L.,Zhang C.,Pei C.‐H.,Han M.‐N.,Li W.
AimsWe aimed to explore Yarrowia lipolytica carbonyl reductases as effective biocatalysts and to develop efficient asymmetric reduction systems for chiral alcohol synthesis.Methods and ResultsYarrowia lipolytica carbonyl reductase genes were obtained via homologous sequence amplification strategy. Two carbonyl reductases, YaCRI and YaCRII, were identified and characterized, and used to catalyse the conversion of 2‐hydroxyacetophenone (2‐HAP) to optically pure (S)‐1‐phenyl‐1,2‐ethanediol. Enzymatic assays revealed that YaCRI and YaCRII exhibited specific activities of 6·96 U mg−1 (99·8% e.e.) and 7·85 U mg−1 (99·9% e.e.), respectively, and showed moderate heat resistance at 40–50°C and acid tolerance at pH 5·0–6·0. An efficient whole‐cell two‐phase system was established using reductase‐expressing recombinant Escherichia coli. The conversion of 2‐HAP (20·0 g l−1) conversion with the solvent of dibutyl phthalate was approximately 70‐fold higher than in water. Furthermore, the two recombinant E. coli displayed biocatalyst activity and enantioselectivity towards several different carbonyl compounds, and E. coli BL21 (DE3)/pET‐28a‐yacrII showed a broad substrate spectrum.ConclusionsA new whole‐cell recombinant E. coli‐based bioreduction system for enantiopure alcohol synthesis with high enantioselectivity at high substrate concentrations was developed.Significance and Impact of the StudyWe proposed a promising approach for the efficient preparation of enantiopure chiral alcohols.
研究领域:
生物化学
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生物技术
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酶学
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DOI
PubMed
高影响因子
APPLIED CLAY SCIENCE
·
2019
·
IF 3.89
Ke Wang,Shiyong Sun,Biaobiao Ma,Faqin Dong,Tingting Huo,Xujuan Li,Yulian Zhao,Haili Yu,Yang Huang
Clay minerals provide an excellent platform for enzyme immobilization , which can improve enzyme activity and stability for industrial applications. In this study, lipase from Aspergillus oryzae was immobilized on 3-aminopropyltriethoxysilane (APTES) amphiphilic functionalized montmorillonite (Mt) support via 1-(3-Dimethylaminopropyl)-3-ethyl-carbodiimide hydrochloride (EDC) spacer. The APTES-Mt and APTES-Mt based nanostructured biocatalyst (lipase-Mt) were characterized by XRD, FT-IR, TEM, SEM and contact angle analysis. Optimal immobilization conditions were determined considering parameters of EDC concentration, initial lipase concentration, pH, and reaction time. The results indicated that lipase-Mt activity was 40.65 U/mg, which was nearly 4-fold higher than that of free lipase under optimal conditions. The Michaelis-Menten constant ( K m ) were found as 0.357 mM and 3.406 mM for free and lipase-Mt, respectively. The maximum reaction rate ( V max ) for the free and lipase-Mt were calculated as 63.69 mM/(L·min) and 312.5 mM/(L·min), respectively. Further, the interfacial activation by amphiphilic surface of APTES-Mt and enlarged catalytic interface contributed to the improved activity and storage stability of lipase-Mt. Thus, this work demonstrate an economically viable method for constructing nanostructured biocatalyst for industrial applications based on covalent immobilization of enzyme onto clay minerals.
研究领域:
酶工程
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纳米生物技术
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工业生物催化
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胶体与界面化学
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应用微生物学
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2012
·Vol. 127
·期 6
·4251-4255
·
IF 1.289
Wentao Liu,Hongdong Duan,Xia Meng,Dawei Qin,Xingjian Wang,Juan Zhang
A series of macroporous beaded terpolymers with epoxy groups were synthesized by suspension polymerization with glycidyl methacrylate (GMA), ethylene glycol dimethacrylate (EGDMA), and the third monomers including styrene, methyl methacrylate, n -butyl acrylate (BA), butyl methacrylate (BMA), and 2-hydroxyethyl methacrylate for immobilization of Candida lipolytica lipase. The effect of various third monomers on loading and activity recovery of immobilized lipase were studied. Terpolymers with BA as the third monomer were found to give the biggest loading of lipase, and the activity recovery of lipase immobilized on poly(GMA-EGDMA-BA) terpolymers reached 79.0%. As the content of BA (%) increasing, the loading of lipase enhanced, but the activity recovery reached 88.5% for the initial stage and decreased to 46.9% at last. The poly(GMA-EGDMA-BA-10) showed an optimal result in lipase immobilization. Lipase immobilized on poly(GMA-EGDMA-BA-10) carriers had broader pH and higher temperature stability. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
研究领域:
生物化学
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高分子科学
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酶工程
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生物催化
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材料化学
✓ 已验证
DOI
高影响因子
Catalysts
·
2017
·Vol. 7
·期 10
·302
·
IF 3.082
Ni Tu,Jianxin Shou,Huaping Dong,Jin Huang,Yimin Li
Clay/chitosan composite beads were prepared and used as the carrier to support lipase by adsorption, to improve the activity and stability of lipase in the hydrolysis of olive oil. Under conditions of pH 6.0, 25 °C and adsorption for 10 h, immobilized lipases on chitosan bead (CB–lipase) and three clay/chitosan composite beads, at different clay to chitosan proportions of 1:8 (CCB-8-lipase), 1:5 (CCB-5-lipase) and 1:3 (CCB-3-lipase), were prepared. By comparing the activity of these immobilized lipases, CCB-5-lipase showed the highest activity, followed by CCB-8-lipase > CCB-3-lipase > CB-lipase; this improvement was attributed to the synergetic effect of enrichment of olive oil by clay at the reaction surface and better biocompatibility of chitosan with lipase molecules. The optimum pH and temperature in the reaction respectively changed from 7.0 and 30 °C for free lipase to 7.5 and 35 °C for immobilized forms. Furthermore, the thermal stability and repeated usability of these immobilized lipases were sequenced as CCB-3-lipase > CCB-5-lipase > CCB-8-lipase > CB–lipase, due to greater rigidity of immobilized lipase with the addition of clay, which was further confirmed by SEM. The study shows that the incorporation of clay with chitosan creates a good synergetic effect to improve the catalytic performance of immobilized lipase on clay/chitosan composite.
研究领域:
生物催化
·
酶工程
·
材料科学
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应用微生物学
·
分子生物学
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DOI
高影响因子
BIOCHEMICAL ENGINEERING JOURNAL
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2019
·
IF 3.371
Liya Zhou,Xucong Luo,Jiaojiao Li,Li Ma,Ying He,Yanjun Jiang,Luyan Yin,Liya Gao
The meso-molding three-dimensionally ordered macroporous alumina (3DOM/m-Al) was synthesized via a dual-templating approach (polystyrene (PS) colloidal crystals as hard template and triblock copolymer P123 as soft template) with hydrous aluminum isopropoxide as precursor. The obtained 3DOM/m-Al was characterized, and the results showed that 3DOM/m-Al had ordered macropores ( ca. 300 nm in diameter) with wormhole-like mesopores, relatively high surface areas (338.1 m 2 /g), large pore volumes (0.4030 cm 3 /g) and tunable pore sizes. The amino functionalized 3DOM/m-Al by aminopropyltriethoxysilane (APTES) was activated by glutaraldehyde and used as support for the immobilization of three different commercial enzymes (Lipase B from Candida antarctica (CALB), penicillin G acylase (PGA) and nitrile hydratase (NHase)). The result of confocal laser scanning microscopy (CLSM) indicated that the enzyme was successfully immobilized onto glutaraldehyde-activated NH 2 -3DOM/m-Al. The effect of the immobilized conditions on the specific activity of enzymes was investigated. Compared with free enzymes, the immobilized enzymes exhibited enhanced thermal stability. The three immobilized enzymes (CALB@NH 2 -3DOM/m-Al, PGA@NH 2 -3DOM/m-Al and NHase@NH 2 -3DOM/m-Al) were applied for the synthesis of palmitic acid, 6-aminopenicillanic acid (6-APA) and acrylamide, respectively. After recycling 10 times, CALB@NH 2 -3DOM/m-Al, PGA@NH 2 -3DOM/m-Al and NHase@NH 2 -3DOM/m-Al retained approximately 76%, 87% and 52% of their initial activities, respectively, indicating that the immobilized enzymes had good operational stability. Therefore, this work documented herein provides a versatile platform for enzyme immobilization with several inherent advantages.
研究领域:
材料科学
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生物催化
·
纳米材料
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酶工程
·
多孔材料
✓ 已验证
DOI
高影响因子
Biomed Research International
·
2015
·Vol. 2015
·期 1
·139179
·
IF 1.579
Jingjing Sun,Yiling Chen,Jun Sheng,Mi Sun
To improve the reusability and organic solvent tolerance of microbial lipase and expand the application of lipase (hydrolysis, esterification, and transesterification), we immobilized marine microbial lipase using different methods and determined the properties of immobilized lipases. Considering the activity and cost of immobilized lipase, the concentration of lipase was fixed at 2 mg/mL. The optimal temperature of immobilized lipases was 40°C and 5°C higher than free lipase. The activities of immobilized lipases were much higher than free lipase at alkaline pH (more than 50% at pH 12). The free lipase lost most activity (35.3%) and immobilized lipases retained more than 46.4% of their initial activity after 3 h heat treatment at 70°C. At alkaline pH, immobilized lipases were more stable than free lipase (more than 60% residue activity at pH 11 for 3 h). Immobilized lipases retained 80% of their activity after 5 cycles and increased enzyme activity (more than 108.7%) after 3 h treatment in tert-butanol. Immobilization of lipase which improved reusability of lipase and provided a chance to expand the application of marine microbial lipase in organic system expanded the application range of lipase to catalyze hydrolysis and esterification in harsh condition.
研究领域:
酶工程
·
分子生物学
·
生物催化
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工业微生物学
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蛋白质化学
·
应用酶学
✓ 已验证
DOI
高影响因子
RENEWABLE ENERGY
·
2019
·
IF 5.439
Huaxia Zhang,Tianshu Liu,Yawei Zhu,Li Hong,Tianfeng Li,Xiqing Wang,Yujie Fu
In the present study, modified polyporous magnetic cellulose beads (PMCBs) were synthesized by several organic amines (EDA, DETA, TETA and AST) grafting PMCBs and then utilized as a new kind of support to immobilize Candida antarctica lipase B (CALB) for biodiesel production. The immobilized lipase catalysts based on PMCBs were characterized by Fourier transform infrared and scanning electron microscopy. The results showed that PMCBs-DETA was a more suitable immobilization support and the catalytic activity of immobilized lipases could reach 1.0 U/mg. Then the synthesized catalyst of CALB-PMCBs-DETA was used to produce biodiesel from Yellow horn seed oil via transesterification reaction. A high biodiesel yield (92.3%) was obtained under the optimal reaction conditions and the main compositions of the prepared biodiesel were tested by GC-MS. Moreover, the catalyst of CALB-PMCBs-DETA could be removed easily by a magnet and recycled at least 5 times. As a new kind of support, the modified PMCBs could be a promising alternative for the carriers of immobilizing enzymes used for the green and efficient production of biodiesel.
研究领域:
生物催化
·
可再生能源
·
酶工程
·
绿色化学
·
生物质转化
✓ 已验证
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2018
·
IF 5.807
Junhua Di,Cuiluan Ma,Jianghao Qian,Xiaolong Liao,Bo Peng,Yucai He
In this study, chemo-enzymatic synthesis of furfuralcohol from biomass-derived xylose was successfully demonstrated by a sequential acid-catalyzed dehydration under microwave and whole-cells reduction. After dry dewaxed chestnut shells (CNS, 75 g/L) was acid-hydrolyzed with dilute oxalic acid (0.5 wt%) at 140 °C for 40 min, the obtained CNS-derived xylose (17.9 g/L xylose) could be converted to furfural at 78.8% yield with solid acid SO 4 2− /SnO 2 -Attapulgite (2.0 wt% catalyst loading) in the dibutyl phthalate-water (1:1, v:v) under microwave (600 W) at 180 °C for 10 min. In the dibutyl phthalate-water (1:1, v/v) media at 30 °C and pH 6.5, the furfural liquor (47.0 mM furfural) was biologically converted to furfuralcohol by recombinant Escherichia coli CCZU-Y10 whole-cells harboring an NADH-dependent reductase (PgCR) without extra addition of NAD + and glucose, and furfural was completely converted to furfuralcohol after 2.5 h. Clearly, this one-pot synthesis strategy can be effectively used for furfuralcohol production.
研究领域:
生物资源技术
·
生物催化
·
绿色化学
·
生物质转化
·
可再生能源
✓ 已验证
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2017
·
IF 4.811
Jianfang Jiang,Jiaqi Zhao,Chunyang He,Baodong Cui,Jun Xiong,Hao Jiang,Juan Ao,Guangyan Xiang
The use of cellulase hydrolysis of straw to produce fermentable sugars has many application prospects. However, cellulase is very expensive, which hampers its industrial applications. To improve cellulase’s catalytic activity and reduce the enzyme cost, magnetite carboxymethyl chitosan/calcium alginate – cellulase bioconjugate (MCCCB) was synthesized via an improved hydrothermal method, molecular self-assembly technology, physical absorption, embedding and covalent bonding. Its loading capacity was 3.95 mg/mL, and the catalytic activity increased to 267.18%. We decreased the release rate, improved the reusability, and enhanced the stability of MCCCB. Corn stalk hydrolysis also greatly improved, and the overall yield of fermentable sugars increased by 698.26%. All of these results indicate that MCCCB could significantly improve the efficiency of cellulase, greatly reduce the cost of enzyme, and effectively promote the production of fermentable sugars.
研究领域:
生物化学工程
·
酶技术
·
生物质转化
·
可再生能源
·
生物催化
✓ 已验证
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2017
·
IF 3.154
Shi-Lin Cao,Xiao Deng,Pei Xu,Zi-Xuan Huang,Jian Zhou,Xue-Hui Li,Min-Hua Zong,Wen-Yong Lou
A novel deep eutectic solvent (DES)–DMSO cosolvent system has been, for the first time, successfully used as the reaction medium for the enzymatic acylation of dihydromyricetin (DMY) catalyzed by the immobilized lipase from Aspergillus niger (ANL). The cosolvent mixture, ChCl:Glycerol–DMSO (1:3, v/v) proved to be the optimal medium. With the newly developed cosolvent, the initial reaction rate of enzymatic acylation of DMY achieved 11.1 mM/h and the conversion of DMY was 91.6%. ANL@PD-MNPs is stable and recyclable in this cosolvent, offering 90% conversion rate after repeated use of 5 times. The lipid-solubility of DMY-16-acetate was 10 times higher than that of its raw materials DMY. The results showed that the DMY-16-acetate product exhibits good antioxidative activity. The present research illustrated that the use of DES–DMSO cosolvent may become a feasible alternative for the synthesis of DMY ester.
研究领域:
生物催化
·
绿色化学
·
酶工程
·
药物化学
·
天然产物化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）