INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2018
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IF 3.909
Yan-Jie Gu,Min-Liang Zhu,Yan-Li Li,Chun-Hua Xiong
A new type of magnetic metal chelating carrier (PCMM-IDA-Cu 2+ ) was prepared for the immobilization of papain, using chitosan as raw material, nano Fe 3 O 4 as magnetic material, SiO 2 as porogen, iminodiacetic acid (IDA) as a chelating ligand, and binding with transition metal ion (Cu 2+ ). The resulting products were well characterized by optical microscopy, scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The BBD (Box-Behnken Design) of RSM (Response Surface Methodology) was applied to analyze the optimum enzyme immobilization conditions. The results showed that the enzyme immobilization capacity was 94.18 mg/g of PCMM-IDA-Cu 2+ , with 7.976 U/mg of relative immobilized enzyme activity under the optimum conditions (pH 6.73, 1.56 mg enzyme/15.0 mg carrier, 30.9 °C), and the recovery of enzyme activity was reached 87.21%. Compared with the free papain, the immobilized papain displayed enhanced enzyme activity, superior enzymatic properties, good operational stability and reusability. It is worth mentioning that the novel carriers exhibited selectively biological adsorption capacity, and this technique is an alternative method for the immobilization of enzyme, making the process more efficient and economic.
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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DOI
PubMed
高影响因子
Microbial Biotechnology
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2017
·Vol. 10
·期 2
·502-512
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IF 3.513
Wei Zhuang,Xiaojing Liu,Jing Yang,Jinglan Wu,Jingwei Zhou,Yong Chen,Dong Liu,Hanjie Ying
Summary Immobilized fermentation has several advantages over traditional suspended fermentation, including simple and continuous operation, improved fermentation performance and reduced cost. Carrier is the most adjustable element among three elements of immobilized fermentation, including carrier, bacteria and environment. In this study, we characterized carrier roughness and surface properties of four types of natural fibres, including linen, cotton, bamboo fibre and silk, to assess their effects on cell immobilization, fermentation performance and stability. Linen with higher specific surface area and roughness could adsorb more bacteria during immobilized fermentation, thereby improving fermentation performance; thus, linen was selected as a suitable carrier and was applied for acetone–butanol–ethanol (ABE) fermentation. To further improve fermentation performance, we also found that microbes of Clostridium acetobutylicum were negatively charged surfaces during fermentation. Therefore, we then modified linen with polyetherimide (PEI) and steric acid (SA) to increase surface positive charge and improve surface property. During ABE fermentation, the adhesion between modified linen and bacteria was increased, adsorption was increased about twofold compared with that of unmodified linen, and butanol productivity was increased 8.16% and 6.80% with PEI- and SA-modified linen as carriers respectively.
研究领域:
生物工程
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微生物学
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DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC
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2017
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IF 2.269
Ying Yuan,Xiaoning Luan,XiaoKu Rana,Mohamed E. Hassan,Deqiang Dou
Cellulase was immobilized on the surface of carrageenan beads activated by using polyethyleneimine and glutaraldehyde, then immobilized cellulase was used to transform ginsenoside Rb 1 . In this work, we studied the functionalization of carrageenan with amine terminal functional group for the covalent immobilization of cellulase. The process of immobilization was performed by amination process on the surface of the carrageenan gel beads with polyethylenimine followed by activation with glutaraldehyde to finally immobilize the enzyme. Different factors affecting the amination and activation processes were studied and their effects on the catalytic activity of the immobilized cellulase were followed, then Fourier transform infrared spectroscopy and scanning electron microscopy were applied to verify the process. Furthermore, the optimum conditions of transformation of ginsenoside Rb 1 were also studied and showed better stability for the immobilized enzyme. The best results were obtained using carrageenan as support and covalent binding method, which consisted of amination process (0.5% PEI (pH 8))) for 3 h and 3% GA in activation process for 3 h. These experiments gave optimum reaction condition of temperature at 60° C and pH 5.0. Enzyme after immobilization exhibited high activity with broader pH and temperature range. Full conversion and kinetic parameters K m and V max for them were also studied. The K m of immobilized enzyme, 3.64 mM, is lower than free one, 4.82 mM; and the V max of immobilized enzyme, 0.04 mM, is lower than free one, 0.06 mM. Results detected also show after using for 5 consecutive times, the immobilized enzyme can retain 60% of its initial activity.
研究领域:
生物技术
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酶学
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药学
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DOI
高影响因子
FOOD HYDROCOLLOIDS
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2018
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IF 5.089
Ziyu Deng,Fang Wang,Bin Zhou,Jing Li,Bin Li,Hongshan Liang
In this study, polygalacturonase (PG) was immobilized in calcium alginate microspheres prepared using endogenous emulsification method and its application in apple juice clarification was evaluated. Preparation conditions of calcium alginate microspheres prepared by endogenous emulsification were optimized, additionally, the formed microspheres were characterized. Under optimal conditions, microspheres with the particle size of 38.0 ± 0.2 μm showed good sphericity, storage stability and a narrow particle size distribution. Meanwhile, single factor experiment and response surface experiment were combined to get the optimum conditions of immobilizing PG. The immobilized enzyme presented the optimum temperature at 60.0 °C, which was almost 10.0 °C higher than the free PG and the activity was less dependent upon pH within the interval of 3.0–4.5 than free enzyme, supporting the immobilized enzyme more stable in apple juice clarification (pH = 4.3 ± 0.1). The immobilized enzyme also exhibited good operational stability and 63.0% of its initial activity retained after three batch reactions. In the present of the immobilized PG, the turbidity of apple juice decreased, as well as apple juice had good thermal and freezing ability.
研究领域:
食品科学
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生物技术
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DOI
高影响因子
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
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2013
·Vol. 172
·期 4
·1859-1865
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IF 1.893
Li Xiaohua,Zhang Zhujun,Li Yongbo
This work presents a new chemiluminescent (CL) probe array assay. The new type CL probe array is based on enzyme mimics of Co 3 O 4 –SiO 2 mesoporous nanocomposite material, which not only have an excellent catalytic effect on the luminol–H 2 O 2 CL reaction in an alkaline medium but also can be used for the immobilization of enzymes. The linear range of the lactose concentration is 3.0 × 10 −7 to 1.0 × 10 −5 g mL −1 and the detection limit is 6.9 × 10 −8 g mL −1 . β-Galactosidase and glucose oxidase were selected as a model for enzyme assays to demonstrate the applicability of Co 3 O 4 –SiO 2 mesoporous nanocomposite material in multienzyme immobilization. The novel bifunctional CL probe array has been successfully applied to the determination of lactose in milk.
研究领域:
生物化学
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分析化学
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DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2017
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IF 4.9
Mingyang Sun,Guanghuan Cheng,Xinlei Ge,Mindong Chen,Cheng Wang,Liping Lou,Xinhua Xu
Stabilized iron sulfide (FeS) nanoparticles have been proven effective in the adsorption of Hg from the water environment. However, previous work with these nanoparticles determined that the separation from the treated water was difficult and time-consuming. In this study, nanoscale FeS-Fe 3 O 4 nanocomposites were firstly synthesized with chitosan as the stabilizer (CTO-MFeS). Then, the Hg adsorption capacity and mechanism were studied. Results showed that the size of the prepared nanoparticles was about 20 nm and the specific surface area was 21.3 m 2 /g. Hg removal by the CTO-MFeS nanoparticles involved both adsorption and precipitation. Further investigation with XPS showed that Hg 2 + was adsorbed on the surface of the CTO-MFeS nanoparticles and reacted with CTO-MFeS to form HgS and [Fe (1 − x) Hg x ]S. It was also found as pH decreased below 4, the adsorption capacity of CTO-MFeS was significantly reduced that might be due to the dissolving of Fe. Additionally, the presence of Cl − resulted in the transformation of Hg 2 + to HgClx 2-x (x = 1, 2, 3, 4) that competed with OH in solution for Hg 2 + and therefore inhibited the adsorption of Hg. Our findings provide additional information that may be useful for a theoretical basis for Hg treatment in water environment.
研究领域:
环境科学
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材料科学
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DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
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2015
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IF 4.513
Juan Qiao,Jin Yong Kim,Yuan Yuan Wang,Li Qi,Fu Yi Wang,Myeong Hee Moon
Fast and effective protein digestion is a vital process for mass spectrometry (MS) based protein analysis . This study introduces a porous polymer membrane enzyme reactor (PPMER) coupled to nanoflow liquid chromatography-tandem MS (nLC-ESI-MS/MS) for on-line digestion and analysis of proteins. Poly (styrene- co -maleic anhydride) (PS- co -MAn) was fabricated by the breath figure method to make a porous polymer membrane in which the MAn group was covalently bound to enzyme. Based on this strategy, microscale PPMER (μPPMER) was constructed for on-line connection with the nLC-ESI-MS/MS system. Its capability for enzymatic digestion with bovine serum albumin (BSA) was evaluated with varied digestion periods. The on-line proteolysis of BSA and subsequent analysis with μPPMER-nLC-ESI-MS/MS revealed that peptide sequence coverage increased from 10.3% (digestion time 10 min) to 89.1% (digestion time 30 min). μPPMER can efficiently digest proteins due to the microscopic confinement effect, showing its potential application in fast protein identification and protease immobilization. Applications of on-line digestion using μPPMER with human plasma and urinary proteome samples showed that the developed on-line method yielded equivalent or better performance in protein coverage and identified more membrane proteins than the in-solution method. This may be due to easy accommodation of hydrophobic membrane proteins within membrane pores .
研究领域:
生物化学
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分析化学
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DOI
PubMed
高影响因子
ACS Applied Nano Materials
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2022
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IF 6.14
Wenyan Wang,Shuo Zheng,Yinhui Hong,Xinlei Xu,Xiang Feng,Heng Song
Immobilization of biomacromolecules offers a favorable protocol for promoting their practical application in biocatalysis, biosensing, and biopharmaceuticals. However, many biomacromolecules are susceptible to deactivation due to the harsh synthetic environment. Here, a simple, scalable, and easily manageable strategy was reported to immobilize several enzymes on the hydrogel–metal–organic-framework nanoparticle composites (HMOFNCs) prepared by simple mixing. That is to say, HMOFNCs are prepared by adding ligands to a metal nitrate mixing solution containing melamine and salicylic acid. Both proteins and DNAs could be immobilized on the surface of HMOFNCs, and their active conformation can be maintained by protecting the biomacromolecules. Moreover, the performance of the biomacromolecules-on HMOFNCs could be fine-tuned by controlling the size of HMOFNCs via the introduction of different amounts of hydrogels. Besides, TPL-on-HMOFNCs also displayed much higher operational stability with a lower loss of conversion rates before six repeated cycles. It is demonstrated that HMOFNCs with the immobilization of active biomacromolecules via simple mixing have great prospects in some significant fields, such as sensing, catalysis, and biomedicine.
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高影响因子
ACS Applied Nano Materials
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2021
·
IF 5.097
Jiawei Lu,Youran Li,Huilin Zhu,Guiyang Shi
Nanoscale particle-based enzyme immobilization carries a risk of dissolving or breaking the material when applied. One effective strategy to improve the stability and functionality of this type of nanomaterial is compounding with polymers. In this study, Fe3O4 nanoparticles were synthesized and coated with SiO2, after which magnetic hollow composite beads with nanoscale porous structures, named, lipase/Fe3O4/PAN (L/FP), were fabricated by compounding polyacrylonitrile and SiO2-coated Fe3O4 nanoparticles to immobilize Candida antarctica lipase B (CALB) in one step. Fourier transform infrared spectroscopy, scanning electron microscopy, the Brunauer–Emmett–Teller method, vibrating sample magnetometer measurements, and thermogravimetry analysis were used to analyze the structure of hollow beads. It was found that composite beads retained nanoscale channels and had a larger specific surface area (27.2 m2/g), a higher pore volume (0.09 cm3/g), and better saturation magnetization values (9.8 emu/g) than PAN hollow beads (6.2 m2/g, 0.03 cm3/g, and 0 emu/g, respectively). After optimizing fabrication and immobilization conditions, L/FP showed a high lipase capacity (50 mg protein/g support) at 2 mg/mL lipase, and the immobilized yield was up to 98.4% when the mass ratio of the starting lipase and support was 1.3 (mg lipase/g support). The immobilized lipase in L/FP showed greater thermal stability and resistance to alkali than free CALB. L/FP also had good stability in most organic solvents. In all tested cycles, it also had better reusability (78.4, 47.2, and 23.8% retained activity after 10, 20, and 30 cycles, respectively) in ester hydrolysis than CALB-immobilized Fe3O4 nanoparticles or PAN beads and had higher activity than the commercial immobilized lipase (Novo 435).
研究领域:
生物化学
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材料科学
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DOI
高影响因子
Catalysts
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2021
·Vol. 11
·期 10
·1158
·
IF 4.146
Zhanyong Wang,Tingting Su,Jingjing Zhao
Genipin was used as a crosslinking agent to prepare magnetic genipin-crosslinked chitosan beads, which were then used as a carrier for immobilizing recombinant cutinase fromFusarium solani(FSC) to obtain immobilized FSC. The optimal temperature for the immobilized FSC was 55 °C, which was 5 °C higher than that of the free enzyme, whereas its optimal pH was increased from 8.0 to 9.0; this indicates that the immobilized FSC had improved pH and thermal stability. After repeated use for 10 cycles, the activity of the immobilized FSC remained at more than 50%; after being stored at 4 °C for 30 days, its activity was still approximately 88%. We also found that the Km of the immobilized FSC was higher than that of the free enzyme. These results indicate that the performance of FSC was improved after immobilization, which is an important basis for the subsequent application of FSC in industrial production.Keywords:immobilization;cutinase;chitosan;genipin
研究领域:
生物技术
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酶学
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材料科学
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DOI
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
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2021
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IF 6.789
Mingjia Yan,Weiquan Li,Jinxin Zhao,Weizhao Yin,Ping Li,Zhanqiang Fang,Li Liu,Jinhua Wu
A biotic iron (Fe 0 ) treatment system combined with mixed microorganisms was applied to remediate cadmium (Cd)-contaminated groundwater under the intervention of sulfate. Due to hydrogenotrophic desulfuration effect, severe iron corrosion was observed in this microbe-collaborative Fe 0 system according to surface morphology analysis as lots of secondary minerals (e.g. magnetite , green rust and lepidocrocite) were generated, which was essential for Cd(II) adsorption and immobilization . The sulfate-mediated biotic Fe 0 system thereafter achieved a significantly enhanced Cd(II) removal efficiency of 86.1%, over 3.3 times than that in the abiotic Fe 0 system. Increasing initial sulfate concentration could improve the removal of cadmium, which further proved that hydrogenotrophic desulfuration played a key role for enhanced Cd removal. According to the experimental results and current reports, the mechanism of Cd(II) removal was revealed into three pathways including adsorption to secondary iron minerals, co-precipitation with iron (hydr)oxides and formation of cadmium sulfide precipitation. Increasing Fe 0 dosages showed positive correlation to Cd(II) removal and neutral pH was preferred to sulfate-mediated biotic Fe 0 corrosion. These results indicated that sulfate-mediated biotic Fe 0 corrosion could greatly relieve the limitation of Fe 0 in Cd(II) immobilization, which could be a promising method to eliminate Cd(II) pollution from groundwater.
研究领域:
环境科学
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微生物学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF CATALYSIS
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2023
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IF 7.3
Yu Cao,Gan Tao,Wei Li,Chuanding Dong,Jingdai Wang,Yongrong Yang
Manipulating the interplay between electron donor and catalytic species is a major approach of optimizing Ziegler-Natta catalysts. To this end, it is essential to reveal the correlation between the involved dynamic processes. In this work, a greatly enhanced mobility of the internal donor tetrahydrofuran (THF) is realized even at room temperature in the MgCl 2 substrate modified with MgCl functionalized polyhedral oligomeric silsesquioxane (POSS-MgCl). A series of spectroscopic characterizations evidence that, thanks to the high mobility of THF, the immobilization of catalytic Ti species and the migration of THF occurs synchronously and leads to a nearly homogenous distribution of Ti sites. In addition, the incorporation of POSS-MgCl promotes the formation of 4-coordinated Mg sites in the substrate. The modified Ziegler-Natta catalyst shows the remarkable performance toward ethylene polymerization, featured by the high catalytic activity (21.6 × 10 6 g PE(mol Ti·h) −1 ) as well as a narrow polydiversity index (3.1) of the synthesized polyethylene. Based on these results, we propose that the Ti immobilization process is directly modulated by the THF migration in this system, which reduces the aggregation of TiCl 4 and enhances the formation of active species.
研究领域:
化学工程
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材料科学
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DOI
高影响因子
危险品化学品经营许可证（带存储）